Silence Therapeutics plc Annual Report 2024

FY2024 Annual Report · Silence Therapeutics plc

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Silence Therapeutics Annual Report 2024

SILENCE THERAPEUTICS PLC

Contents

1
Strategic Report
3

2
Governance

Board of Directors
17
Corporate Governance Report
23
Audit and Risk Committee Report
29
Remuneration Committee Report
32
Directors’ Report
57

Financial Statements
60
Independent Auditors’ Report to the Members of Silence Therapeutics Plc
61
Consolidated Income Statement
67
Consolidated Statement of Comprehensive Income
67
Consolidated Balance Sheet
68
Consolidated Statement of Changes in Equity
69
Consolidated Statement of Cash Flows
70
Notes to the Consolidated Financial Statements
71
Company Balance Sheet
101
Company Statement of Changes in Equity
102
Notes to the Company Financial Statements
103
Company Information and Advisers
114

SILENCE THERAPEUTICS PLC

Strategic Report
Business Overview
We are a biotechnology company focused on discovering and developing novel molecules incorporating short
interfering ribonucleic acid, or siRNA, to inhibit the expression of specific target genes thought to play a role in the
pathology of diseases with significant unmet medical need. Our siRNA molecules are designed to harness the body’s
natural mechanism of RNAi by specifically binding to and degrading messenger RNA, or mRNA, molecules that encode
specific targeted disease-associated proteins in a cell. By degrading the message that encodes the disease-associated
protein, the production of that protein is reduced and its level of activity is lowered. In the field of RNAi therapeutics, this
reduction of disease-associated protein production and activity is referred to as “gene silencing.” Our proprietary mRNAi
GOLD™ (GalNAc Oligonucleotide Discovery) platform consists of siRNA product candidates designed to precisely
target and ‘silence’ specific disease-associated genes in the liver. Using our mRNAi GOLD platform, we have generated
siRNA product candidates both for our internal development pipeline as well as for out-licensed programmes with third-
party collaborators. Our wholly owned pipeline is currently focused in three therapeutic areas of high unmet need:
cardiovascular disease, hematology and rare diseases.
Divesiran (SLN124) is our wholly owned siRNA product candidate designed to inhibit TMPRSS6 expression in the
liver. TMPRSS6 is a negative regulator of hepcidin, the body's master regulator of iron metabolism, including its
absorption, distribution and storage. Divesiran has shown preclinical potential in several hematological disorders and
proof-of-mechanism in a Phase 1 healthy volunteer trial. Divesiran is currently being evaluated in the SANRECO Phase
2 clinical trial in polycythemia vera, or PV, patients. We believe divesiran has the potential to be the first-in-class siRNA
in PV. PV is a rare, myeloproliferative neoplasm – a type of blood cancer - characterized by the excessive production
of red blood cells, often resulting in elevated hematocrit, or HCT, levels. By silencing TMPRSS6 in PV patients, divesiran
aims to increase hepcidin production and release by liver hepatocytes, leading to the restriction of iron to the bone
marrow and, thus, reducing the excessive production of red blood cells, a process dependent on availability of iron. In
December 2024, we presented positive interim results from the Phase 1 portion of the SANRECO clinical trial at the
American Society of Hematology (ASH) annual meeting. Interim results showed divesiran substantially reduced
phlebotomy requirements and lowered HCT levels following infrequent dosing in a range of PV patients. Divesiran has
been well tolerated to-date with no dose-limiting toxicities. In December 2024, we also announced the first subject has
been dosed in the Phase 2 portion of the SANRECO clinical trial which is currently underway. The U.S. Food and Drug
Administration, or FDA, has granted divesiran Fast Track and orphan drug designations for PV. In December 2024, the
European Commission, or EC, granted divesiran orphan drug designation for PV in Europe.
Zerlasiran (SLN360) is our wholly owned siRNA product candidate, which is designed to lower the body's production
of apolipoprotein(a), a key component of lipoprotein(a), or Lp(a), that has been associated with an increased risk of
cardiovascular events. Zerlasiran works by targeting messenger RNA required to translate the LPA gene into particles
of Lp(a), effectively ‘silencing’ the gene to reduce Lp(a) production. High Lp(a), defined as 125nmol/L or higher, is a
genetically determined cardiovascular risk factor affecting at least 20% of the world’s population and is associated with
a high risk of heart attack, stroke and aortic stenosis. Unlike low-density lipoprotein, or LDL, Lp(a) levels are
predominantly genetically determined, typically by age five, and unaffected by diet or lifestyle. There are currently no
approved medicines that selectively lower Lp(a). Lp(a) levels can be measured by a simple blood test and while there
is no generalized consensus on Lp(a) risk thresholds, growing evidence supports three main levels: Low or Normal (less
than 75 nmol/L), Elevated (75 nmol/L to 124 nmol/L) and High (125 nmol/L or higher). A recent US based registry study
in over 16,000 individuals showed that there is substantial risk of major cardiovascular events in individuals with elevated
levels below the current accepted risk threshold of 125 nmol/L. Guidelines from the European Atherosclerosis Society,
or EAS, and Canadian Cardiovascular Society, or CCS, suggest at least one test in an adult lifetime. The American
College of Cardiology, or ACC, and American Heart Association, or AHA, recommend testing for those with a family
history of premature atherosclerotic cardiovascular disease, or ASCVD, or personal history of ASCVD. In Phase 1 and
Phase 2 clinical trials, zerlasiran was shown to substantially lower Lp(a) levels in ASCVD patients with persisting effects
following infrequent dosing and was observed to be well tolerated with no major safety concerns. During the fourth
quarter 2024, we received positive regulatory feedback from the FDA and European Medicines Agency, or EMA, on the
Phase 3 cardiovascular (CV) outcomes study design for zerlasiran in patients with high Lp(a). We are engaged in global
partnership discussions to seek a third-party partner for potential Phase 3 development of zerlasiran as well as potential
future commercialization activities.
In addition to our wholly owned clinical pipeline, we have a third siRNA product candidate from our mRNAi GOLD
platform in Phase 1 development in an undisclosed indication through our collaboration with AstraZeneca.

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We believe the potential for our mRNAi GOLD platform to address disease-associated genes in the liver is
substantial and are progressing several undisclosed preclinical programmes that have shown promising results. We are
committed to maximizing our mRNAi GOLD platform by advancing a pipeline of both wholly owned and partnered
programmes.

Our Pipeline
We are advancing several siRNA programmes in the clinic developed from our proprietary mRNAi GOLD platform.

Background on siRNA Molecules and RNA Interference
Messenger RNA, or mRNA, plays an essential role in the process used by cells to translate genetic information from
DNA to create proteins. Transcription from DNA in the cell nucleus generates different types of RNA, including mRNA,
which carries in the sequence of its nucleotides the genetic information which serves as molecular blueprints required
for translation, or protein synthesis, outside of the nucleus where proteins are made. In some cases, cells produce
mRNA erroneously, resulting in synthesis of too much of a particular protein or a mutated protein variant, which can
lead to disease. Our siRNAs are designed to bind to undesirable mRNA, whereupon a natural process known as RNA
interference, or RNAi, is triggered, resulting in catalytic degradation of the mRNA and reduced production and activity
of the disease-associated protein.
RNAi is a naturally occurring biological pathway within cells for sequence-specific silencing and regulation of gene
expression. RNAi was discovered by Andrew Fire and Craig Mello, for which they were awarded the 2006 Nobel Prize
in Physiology or Medicine. RNAi therapeutics represent a novel advance in drug development that has the potential to
transform the care of patients with genetic and other diseases. Historically, the pharmaceutical industry had developed
only small molecules or recombinant proteins to inhibit the activity of disease-associated proteins. While this approach
is effective for many diseases, a number of proteins cannot be inhibited by either small molecules or recombinant
proteins. Some proteins lack the binding pockets small molecules require for interaction. Other proteins are solely
intracellular and are therefore inaccessible to recombinant protein-based therapeutics, which are limited to cell surface
and extracellular proteins. The unique advantage of RNAi is that, instead of targeting proteins, RNAi silences the
expression of genes themselves via the targeted destruction of the mRNAs made from the gene. Rather than seeking
to inhibit a protein directly, the RNAi approach works upstream to prevent its creation in the first place.
Once inside a cell, siRNA molecules are recognized by the endogenous RNAi cellular machinery, which removes
one of the strands, referred to as a passenger strand, of the siRNA construct, thereby allowing the other strand, referred
to as a guide strand, to find its target mRNA and bind to it through Watson-Crick base pairing. This site-specific binding

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triggers the biological process of RNAi interference, by which natural cellular machinery degrades target mRNA bound
by the guide strand and thereby prevents it from being translated into functional proteins.
Our medicines are designed to harness this natural pathway to develop a new generation of therapeutics by
designing tailored siRNA sequences that are able to bind through Watson-Crick base pairing to mRNAs that code for
specific disease-associated genes, or genes that regulate them. Our siRNA molecules are administered by
subcutaneous injection. Once administered, our siRNA molecules are taken up specifically by target liver cells or cleared
from the body within hours. A single siRNA molecule, once in the liver and incorporated into the RNAi cellular machinery,
can degrade large numbers of targeted mRNAs due to the catalytic nature of the cell’s RNAi machinery. Because the
catalytic activity of the RNAi pathway eventually fades with gradual degradation of the guide strands, RNAi-mediated
protein reduction is not permanent. In our preclinical and clinical studies, we have observed a durable, dose-dependent
silencing effect with our product candidates following subcutaneous injection. The graphic below shows the steps
involved in the pairing of our siRNA molecules with the bases contained in the mRNA sequence for a particular target
gene.

We believe that siRNA molecules can, in theory, be engineered to bind specifically to and silence almost any gene
in the human genome to which siRNA can be delivered. This potentially broad application of siRNA therapeutics could
allow them to become a new major class of drugs. We are currently able to deliver siRNA molecules to liver cells using
GalNAc for receptor-mediated targeting. GalNAc is an amino-modified monosaccharide that binds to asialoglycoprotein
receptors, or ASGPRs, with high affinity and specificity. When GalNAc-conjugated siRNA molecules reach the surface
of liver cells, they are internalized in those cells, with those not internalized being excreted. Once internalized, the
siRNAs specifically bind to their target mRNAs, degrading them through the cell’s natural RNAi pathway. This GalNAc-
siRNA drug modality is intended to enable precision medicine through the accuracy of Watson-Crick base pairing of the
siRNA to its target gene mRNA, coupled with the specificity of GalNAc-mediated delivery to the target gene-containing
liver cell.
Our mRNAi GOLD™ platform uses a novel structure of double-stranded RNA with chemical modifications designed
to improve the stability and efficacy of our siRNA molecules as well as to enhance delivery to targeted liver cells. We

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incorporate proprietary chemical modifications to enhance drug properties of our siRNA molecules, such as potency,
stability and tissue distribution. We believe this approach results in a powerful modular technology that will be well-
suited to tackle life-changing diseases. Particular siRNA molecules are designed to reduce the levels of a disease-
associated protein directly, such as in the case of zerlasiran. In preclinical and clinical studies, zerlasiran was shown to
directly reduce Lp(a) expression. Alternatively, in cases in which a disease-associated protein is normally subject to
inhibition by a regulatory protein, siRNA molecules are designed to increase the levels of the disease-associated protein
by silencing the inhibitory protein, thereby relieving inhibition and indirectly increasing levels of the protein normally
subject to inhibition. In preclinical and clinical studies, divesiran was shown to indirectly up-regulate hepcidin levels by
reducing the expression of a specific gene, TMPRSS6, which normally inhibits the production of hepcidin. We will use
this approach to address ‘iron loading’ anemia conditions in which hepcidin expression is typically low. Using these
techniques, we believe we can design siRNA molecules to decrease high protein levels, and in some cases, to increase
low protein levels, depending on the particular disease genes being targeted.
Our mRNAi GOLD™ Platform
Our mRNAi GOLD™ platform comprises elements of our GalNAc-siRNA toolbox, our liver cell targeting technology
and our target selection and screening process.
GalNAc-siRNA Toolbox.
Our mRNAi GOLD™ platform is a toolbox comprising several different elements that can be incorporated into our
double-stranded siRNA structure, known as blunt-ended 19-mers, either singly or in different combinations depending
on individual siRNA sequences. The toolbox elements include:

sugar modifications of one or more select individual nucleotides;

stabilizing modifications of one or more internucleoside linkages in the sense and antisense strands;

stabilizing modifications at one or more of the ends of the siRNA molecules; and

a versatile linker chemistry for GalNAc ligand conjugation in various numbers and configurations.
When applying these elements of our toolbox, we also aim to reduce the overall content of the sugar modifications
and the number of undefined stereogenic centers in the siRNA molecule.
Liver Cell Targeting Technology. Blood flow and fenestra, or small openings in the endothelium, result in a large
amount of the injected dose of a conjugated siRNA passing through the liver and reaching the main cell type of the liver
known as a hepatocyte. Hepatocytes are cuboidal epithelial cells that line the liver sinusoids. Individual hepatocytes
have approximately 0.5 to 1.0 million cell surface ASGPRs. GalNAc binds to ASGPRs with high affinity so that when
GalNAc-conjugated siRNA reaches the hepatocytes, they are internalized into the cells where siRNA can bind and, as
a result, can degrade the target mRNA, which in turn reduces production of the encoded protein and that protein’s
activity, thereby silencing the respective gene. Only a small fraction of the initial dose reaches the hepatocyte and the
right compartment of the cell, but once the siRNA is there, it can stay active and intact for several months, allowing a
small number of internalized siRNA molecules to exert a potent effect on the target mRNA. We apply the toolbox
elements in the lead optimization phase to identify candidates that we believe will be potent with a long duration of action
and have a favourable safety profile.
Target Selection and Screening Process. We are able to source potential product candidates through a
proprietary target selection process. The selection of new targets involves a careful analysis of human genetics
evidence, the biology underlying an indication, disease epidemiology and addressable population, the current standard
of care and resulting medical need, the commercial landscape and the envisaged clinical path.
Our screening process relies on a proprietary in silico algorithm that seeks to predict the most efficacious and
specific siRNAs for any given target. This bioinformatics function is designed to continuously improve in silico predictions
for finding potentially potent and safe siRNA sequences. The highest scoring drug candidates subsequently undergo a
multi-step evaluation process involving several rounds of in vitro screening in cell lines and primary hepatocytes to
identify the most potent molecules. Top candidates identified in vitro are then tested for safety and potential efficacy in
animal models. At this point in the process, additional modification patterns and new chemistries are introduced for
improvement of activity and duration of action while maintaining the desired safety profile. To be selected as a drug
candidate for clinical trials, it further needs to be shown that a molecule is well tolerated, elicits no serious adverse
effects, and achieves strong and long-lasting knockdown of the targeted gene in a study with non-human primates.

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Divesiran (SLN124)
Overview
Divesiran is our wholly owned siRNA product candidate in Phase 2 development for PV. We believe divesiran has
the potential to be the first-in-class siRNA in PV. PV is a rare myeloproliferative neoplasm - a type of blood cancer -
characterized by the overproduction of blood cells and platelets, often resulting in elevated HCT. Elevated HCT above
45-percent is associated with a four-times higher rate of death from cardiovascular or thrombotic events. PV is
associated with a range of burdensome symptoms including fatigue, cognitive disturbance and pruritis and additionally,
longer term can transform to myelofibrosis and Acute Myeloid Leukemia. The aim of treatment is to maintain HCT less
than 45%, a level that is associated with a reduced incidence of thrombosis and cardiovascular-associated death. The
current standard of care includes repeated phlebotomies to reduce HCT and/or cytoreductive agents to reduce red blood
cell production. There are currently no approved therapies that specifically target red blood cells and HCT. PV is a rare
disease affecting approximately 150,000 individuals in the United States and around 3.5 million individuals worldwide.
Divesiran is administered subcutaneously and works by specifically binding to and inducing RNAi-mediated
degradation of mRNAs made from the TMPRSS6 gene. TMPRSS6 is a negative regulator of hepcidin, which is the main
hormone controlling iron homeostasis in the body. By silencing TMPRSS6 in PV patients, divesiran aims to increase
hepcidin production and release by liver hepatocytes, leading to the restriction of iron to the bone marrow and, thus,
reducing the excessive production of red blood cells, a process dependent on availability of iron.
In December 2024, we presented positive interim results from the Phase 1 portion of the SANRECO Phase 1/2
clinical trial of divesiran in PV patients at the 66th American Society of Hematology (ASH) Annual Meeting. Interim
results showed divesiran substantially reduced phlebotomy requirements and lowered HCT levels following infrequent
dosing in a range of PV patients. Further, divesiran has been well tolerated to-date with no dose-limiting toxicities. In
December 2024, we also announced that the first subject has been dosed in the Phase 2 portion of the SANRECO
clinical trial which is currently underway. We anticipate full enrolment by year-end 2025. The FDA has granted divesiran
Fast Track and orphan drug designations for PV. In December 2024, the EC granted divesiran orphan drug designation
for PV in Europe.
Disadvantages of existing treatment options
The primary treatment goal in PV is to reduce the risk of thrombotic events by reducing hematocrit (the percent
volume of red blood cells in the blood) to within target levels. The mainstay of treatment is therapeutic phlebotomy to
reduce the number of blood cells by regularly removing blood from the patient. Phlebotomy results in erratic, suboptimal
control of hematocrit, and regular phlebotomies can be burdensome to the patient. Patients over 60, or those with prior
thrombotic events or additional cardiovascular risk factors are also treated with chemotherapy drugs (cytoreductive
agents) to suppress blood cell production. The majority of these patients are treated with hydroxyurea, which is poorly
tolerated and carries the risk of potential long term side effects. Patients who are resistant or intolerant to hydroxyurea
may be treated with the JAK2 inhibitor ruxolitinib (Jakafi), which carries the risk of thrombocytopenia (low platelet count).
Finally, some patients are treated with synthetic hepcidin mimetic dosed weekly by subcutaneous injection in clinical
trials. In contrast to synthetic hepcidin mimetics, divesiran elevates endogenous hepcidin produced and secreted by the
liver, avoiding high local concentrations of hepcidin at the injection site. Based on initial results from the Phase 1 portion
of the SANRECO clinical trial, divesiran has shown the potential to substantially reduce phlebotomy requirements and
lower HCT levels following infrequent dosing in a range of PV patients. Importantly, divesiran has also been well
tolerated to-date with no dose-limiting toxicities.
GEMINI Trial
The GEMINI trial was a randomized, double-blind, placebo controlled, single-ascending dose study to investigate
the safety, tolerability, PK and PD response of divesiran (1.0, 3.0 and 4.5 mg/kg doses) administered subcutaneously
in 24 healthy volunteers. Key outcomes included:

All 3 dose levels were well tolerated with no serious or severe treatment emergent adverse events, or
TEAEs, leading to withdrawal.

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Average hepcidin, a key endogenous regulator of iron balance and distribution, increased up to ~4-fold after
a single dose with effect sustained for at least 2 months.

Serum iron reduced by ~50% after a single dose with effect sustained for at least 2 months.

Divesiran was rapidly distributed (median tmax was 4.0 or 5.0 hours) and largely eliminated from plasma
within 24 hours post-dose in all dosing groups. Divesiran plasma concentrations increased in a greater than
dose-linear fashion between dosing groups.

All divesiran doses induced marked reductions in transferrin saturation, or TSAT; absolute levels of TSAT
achieved (10–16%) are below the level (< 20%) where iron availability to tissue is restricted and at or below
that (< 16%) required to support normal erythropoiesis in health.
GEMINI II Phase 1 Programme
The GEMINI II Phase 1 clinical trial evaluated divesiran in non-transfusion dependent thalassemia patients. In the
trial, divesiran was observed to be well tolerated with no safety issues identified. While proof of mechanism has been
established in healthy volunteers, the effects on indicators of iron metabolism were variable in the trial population of
heterogeneous thalassemia subjects. Accordingly, we have made the decision to prioritize R&D efforts related to the
ongoing PV programme and do not have plans to advance development in thalassemia at this time.
SANRECO Phase 1/2 Programme
SANRECO is Phase 1/2 clinical trial with an open-label dose escalation phase followed by a randomized placebo
controlled and double-blind phase of divesiran in PV patients.
The Phase 1 portion of the SANRECO clinical trial is a 34-week, open-label study evaluating divesiran (3 mg/kg, 6
mg/kg and 9 mg/kg) administered subcutaneously every six weeks for four doses, with a 16-week follow-up period
following the date of the last administered dose in 21 PV patients. Key inclusion criteria include a PV diagnosis and a
history of requiring at least three phlebotomies in the last six months or five phlebotomies in the last year prior to
screening. Patients are allowed to be on stable doses of cytoreductive agents. Given the exploratory nature of this
Phase 1 clinical trial, both well-controlled patients - defined as those with HCT levels at 45% or less – as well as those
with HCT levels greater than 45% at baseline on current standard of care treatment were enrolled.
In December 2024, we presented positive interim results from the Phase 1 Portion of the SANRECO Phase 1/2
clinical trial of divesiran in 19 PV patients at the 66th ASH Annual Meeting. Interim results showed divesiran substantially
reduced phlebotomy requirements and lowered HCT levels following infrequent dosing in a range of PV patients.

Interim results included 19 PV patients with a combined history of 79 phlebotomies prior to enrolment.
Following dosing with divesiran , only five phlebotomies occurred during the 18-week treatment period and
all five occurred in patients who entered the trial with high baseline HCT levels (over 45%). Two
phlebotomies occurred in the 16-week follow-up period following the last administered dose.

A sustained reduction in HCT during the treatment period and favourable effects on indices of iron
metabolism were observed. Hepcidin levels increased and were sustained within physiological levels in all
dose groups, demonstrating consistent target engagement.

Divesiran continues to be well tolerated to-date with no dose limiting toxicities.
The Phase 1 portion of the SANRECO clinical trial completed follow-up in February 2025. Phase 1 data
presentations are planned for medical congresses in 2025.
In December 2024, we also announced the first subject has been dosed in the Phase 2 portion of the SANRECO
clinical trial which is currently underway. We anticipate full enrolment by year-end 2025.
Zerlasiran (SLN360)
Overview
Zerlasiran is a siRNA molecule designed for the treatment of cardiovascular disease associated with elevated Lp(a),
a lipoprotein in the blood. Available human data validate Lp(a) as an independent risk factor increasing the chances of
developing premature cardiovascular diseases, including coronary heart disease and unstable angina, as well as
myocardial infarction and ischemic stroke. Zerlasiran is administered by subcutaneous injection and has the potential

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to reduce these diseases by specifically binding to and inducing RNAi-mediated degradation of the mRNAs made from
LPA, the gene that encodes apolipoprotein(a), a protein specifically found in Lp(a). Zerlasiran’s mode of action creates
an opportunity to develop this product candidate for several indications for which Lp(a) has been shown to be a causal,
independent risk factor.
population. The incidence of elevated Lp(a) is thought to be higher in people with established cardiovascular disease
and calcific aortic valvular stenosis. Additionally, elevated Lp(a) concentrations are associated with an increased risk of
myocardial infarction and ischemic stroke, particularly in stroke patients 55 years of age and younger. There is a genetic
link between plasma Lp(a) level and cardiovascular risk. Mutations that genetically cause elevated Lp(a) levels have
been linked with increases in myocardial infarction, ischemic stroke, carotid stenosis, peripheral arterial disease
(including femoral artery stenosis), abdominal aortic aneurysm, obstructed coronary vessels (i.e. coronary
atherosclerotic burden), earlier onset of coronary artery disease, cardiovascular and all-cause mortality, increased risk
of heart failure and reduced longevity. Importantly, these causal relationships are independent of concentrations of other
lipids and lipoproteins, including low-density lipoprotein, or LDL, and conventional cardiovascular disease risk factors.
Conversely, a genetically determined decrease in Lp(a) has been associated with a 29% lower risk of coronary artery
disease, 31% lower risk of peripheral vascular disease, 17% lower risk of heart failure, 13% lower risk of stroke and a
37% lower risk of aortic stenosis.
In Phase 1 and 2 clinical trials, zerlasiran has shown the potential to substantially reduce Lp(a) levels in ASCVD
patients, with maximum reductions exceeding 90% during the treatment period and effects persisting 60 weeks following
first dose. Zerlasiran continues to be well tolerated to-date with no major safety issues. Based on clinical data generated
to-date, we believe zerlasiran has promising potential to address major unmet needs in cardiovascular disease. We are
engaged in global partnership discussions to seek a third-party partner for potential Phase 3 development of zerlasiran
as well as potential future commercialization activities.
Disadvantages of existing treatment options
Lp(a) is not susceptible to lifestyle changes and there are no currently available pharmacological treatments that
cause an appreciable reduction in Lp(a). The only existing treatment to reduce Lp(a) is apheresis, which involves the
removal of blood plasma from the body by the withdrawal of blood, its separation into plasma and cells, and the
reintroduction of the cells, used especially to remove antibodies in treating autoimmune diseases. This process can take
between two and four hours and is performed every one to two weeks. Consequently, it is invasive and burdensome for
patients, and it is only available at limited centers at a high cost. Apheresis is primarily used in Europe and it is not
incorporated in the treatment guidelines in the United States.
There are currently no approved lipid-lowering agents specific to Lp(a). Several non-specific agents, largely
targeting LDL cholesterol, have been observed to have only marginal or modest Lp(a) reductions, including ezetimibe
(7%), niacin therapy (23%), cholesteryl ester transfer protein, or CETP, inhibitors (25-60%), and antisense
oligonucleotide-mediated inhibition of apolipoprotein B (ApoB) by mipomersen (26%). Additionally, two monoclonal
antibodies that inhibit proprotein convertase subtilisin/kexin type 9, or PCSK9, have been observed to reduce Lp(a)
levels by 20%-30%. However, randomization studies have suggested that to produce a clinically significant reduction in
cardiovascular risk, a larger reduction in Lp(a) may be required, something that we believe may be achieved by targeted
RNA-based approaches such as ours.
APOLLO Phase 1 Clinical Programme
The APOLLO Phase 1 clinical programme was a global randomized, double-blind, placebo controlled, single-
ascending dose and multiple-ascending dose study investigating the safety, tolerability, pharmacodynamic and
pharmacokinetic response of zerlasiran administered subcutaneously in healthy adults and ASCVD patients with high
Lp(a) levels of approximately greater than 60mg/dL or less than 150 nmol/L.
In April 2022, we presented positive results from the single-ascending dose portion of the APOLLO Phase 1
programme in 32 healthy adults with high Lp(a) greater than 150 nmol/L in a late-breaking presentation at the American
College of Cardiology, or ACC, Annual Scientific Session & Expo. Results were simultaneously published in The Journal
of American Medical Association, or JAMA. In the single dose trial, participants in the top two dose groups (300 mg and
600 mg) were observed to have experienced up to a 96% and 98% median reduction in Lp(a) levels, respectively, and
median reductions of up to 71% and 81% from baseline persisted at 150 days. Other efficacy measures included the
effects of zerlasiran on low-density lipoprotein cholesterol (LDL cholesterol) and ApoB, both of which are associated
with an increased risk of cardiovascular events. The highest doses of zerlasiran reduced LDL cholesterol and ApoB by

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about 25%. In the trial, zerlasiran was observed to be well tolerated with no serious safety concerns reported. In
November 2022, we presented a further analysis from the APOLLO trial up to 365 days at the American Heart
Association’s 2022 Annual Scientific Sessions. This analysis showed median time-averaged Lp(a) reductions over 150
days exceeded 80% in the zerlasiran 300 mg and 600 mg dose groups. At day 365, some participants still exhibited
substantially reduced levels of Lp(a) of approximately 50% compared to baseline. Additionally, the extension data we
presented related to dosing of zerlasiran to day 365 showed no new drug related safety findings.
In November 2023, we reported positive results from the multiple-ascending dose portion of the APOLLO
programme in 36 adults with stable ASCVD and high Lp(a) greater than 150 nmol/L. In the multiple dose trial, zerlasiran
(200 mg, 300 mg and 450 mg) was administered twice subcutaneously at two different dosing intervals to ASCVD
patients. This data demonstrated a significant reduction from baseline in Lp(a) of up to 99% at 90 days following injection
of repeated doses. Lp(a) levels remained approximately 90% lower than baseline at 201 days (end of treatment period)
at the two highest doses. A dose dependent reduction in low-density lipoprotein cholesterol, or LDL cholesterol, and
apolipoprotein B, or ApoB, was also observed. Zerlasiran continued to be observed to be well tolerated with no serious
safety issues identified.
In April 2024, additional results from the APOLLO Phase 1 programme were published in the JAMA and our analysis
showed that zerlasiran was observed to be well tolerated and significantly reduced Lp(a) after single and multiple
dosing regimens.
ALPACAR-360 Phase 2 Clinical Programme
The ALPACAR-360 Phase 2 clinical trial was a randomized, double-blind, placebo-controlled trial in 178 patients
with high Lp(a) greater than 125nmol/L at high risk of ASCVD events. Baseline Lp(a) concentration was 213
nmol/L. Patients were randomly assigned to one of three active subcutaneous doses of zerlasiran (300 mg Q16 weeks,
300 mg Q24 weeks, 450 mg Q24 weeks) or placebo. The primary endpoint was time-averaged change in Lp(a) from
baseline to 36 weeks. Secondary endpoints included time-averaged changes in LDL-C as well as time-averaged Lp(a)
to 48 weeks (end of treatment period) and 60 weeks (end of study). This is the first study to report time-averaged Lp(a)
analyses, which more accurately evaluates the effects of treatment over time, including intervals between doses.
In November 2024, positive results from the ALPACAR-360 Phase 2 clinical trial were presented at the American
Heart Association’s 2024 Scientific Sessions and simultaneously published in JAMA. Results from the study showed
that zerlasiran produced greater than 80% mean time-averaged placebo-adjusted reductions from baseline in Lp(a)
concentrations over 36 weeks. Maximum Lp(a) reductions exceeded 90%. At the final visit, 60 weeks following initial
drug administration, reductions in Lp(a) persisted with infrequent dosing. Zerlasiran was also observed to reduce time-
averaged LDL-C by ~25-30% and Apo B by ~10-15%. Zerlasiran was observed to be well tolerated with no major safety
issues identified.
Phase 3 Preparedness
During the fourth quarter 2024, we received positive regulatory feedback from the FDA and EMA on the Phase 3
cardiovascular outcomes study design for zerlasiran in patients with high Lp(a). We also progressed core Phase 3
readiness activities for zerlasiran, including the scale up of product supply to enable the full start-up of the Phase 3
CVOT study in the first half of 2025. We are engaged in global partnership discussions for this programme and will only
initiate the Phase 3 cardiovascular outcomes study once a partner is secured.
Collaborations
AstraZeneca
In March 2020, we entered into a collaboration agreement with AstraZeneca to discover, develop and commercialize
siRNA therapeutics for the treatment of cardiovascular, renal, metabolic and respiratory diseases. Under this agreement,
AstraZeneca made an upfront cash payment to us of £17.1 million ($20.0 million) in May 2020. AstraZeneca made an
additional unconditional cash payment to us of £30.8 million ($40.0 million) which was received in May 2021. In March
2020, an affiliate of AstraZeneca also subscribed for 4,276,580 new ordinary shares for an aggregate subscription price
of $20.0 million.
The collaboration covers five targets initially, with AstraZeneca having the option to extend the collaboration to a further
five targets. AstraZeneca has agreed to pay us $10.0 million upon the exercise of each option to collaborate on an

SILENCE THERAPEUTICS PLC

additional target. In May 2023, AstraZeneca nominated the first product candidate under our collaboration, triggering a
£7.9 million ($10 million) option fee to us to advance development on an undisclosed programme. In February 2024,
AstraZeneca initiated a Phase 1 clinical trial for this undisclosed programme which triggered another £7.9 million ($10
million) milestone payment to us. In March 2024, we completed our obligations for the second product candidate under
the collaboration. For each target selected, we will be eligible to receive up to $140.0 million in potential milestone
payments upon the achievement of milestones relating to the initiation of specified clinical trials, the acceptance of
specified regulatory filings and the first commercial sale in specified jurisdictions. For each target selected, we will also
be eligible to receive up to $250.0 million in potential commercial milestone payments, upon the achievement of specified
annual net sales levels, as well as tiered royalties as a percentage of net sales ranging from the high single digits to the
low double digits.
Mallinckrodt
In July 2019, we entered into a collaboration agreement with Mallinckrodt to develop and commercialize RNAi drug
targets designed to silence the complement cascade in complement-mediated disorders. In connection with the
execution of this agreement, Mallinckrodt made an upfront cash payment to us of £16.4 million ($20.0 million). Under a
separate subscription agreement, Cache Holdings Limited, a wholly owned subsidiary of Mallinckrodt, concurrently
subscribed for 5,062,167 new ordinary shares for an aggregate subscription price of $5.0 million. Under the agreement,
we granted Mallinckrodt an exclusive worldwide license to our C3 targeting programme, SLN501, with options to license
two additional undisclosed complement-mediated disease targets from us. In July 2020, Mallinckrodt exercised options
on the two additional complement targets.
In March 2023, we reacquired exclusive worldwide rights from Mallinckrodt to the two undisclosed preclinical
complement targets. Under the terms of the modified agreement, we did not make any upfront payment to get the two
assets back and will potentially pay future success-based milestones and low single digit royalties on net sales if the
projects advance. SLN501, the C3 targeting programme, remained under the original collaboration agreement. In March
2024, Mallinckrodt notified us that they will not pursue further development of SLN501 following the completion of the
phase 1 clinical trial. This completion also concludes all required development activities and commitments under the
collaboration.
Hansoh
In October 2021, we announced a collaboration agreement with Hansoh, one of the leading biopharmaceutical
companies in China, to develop siRNAs for three undisclosed targets leveraging our proprietary mRNAi GOLD™
platform. Under the terms of the agreement, Hansoh will have the exclusive option to license rights to the first two targets
in Greater China, Hong Kong, Macau and Taiwan following the completion of phase 1 trials. We will retain exclusive
rights for those two targets in all other territories. We are responsible for all activities up to option exercise and will retain
responsibility for development outside the China region post phase 1 trials. Hansoh will also have the exclusive option
to license global rights to a third target at the point of IND filing. Hansoh will be responsible for all development activities
post option exercise for the third target. Hansoh made a £11.9 million ($16 million) upfront payment to us in December
2021. We achieved our first £1.5 million ($2 million) research milestone payment in the Hansoh collaboration in April
2022. In 2023, we achieved two additional preclinical milestones and received £3.2 million ($4 million) from the
collaboration. In 2024, we achieved an additional preclinical milestone of £1.6 million ($2.0 million) from the Hansoh
Collaboration. In December 2024, Hansoh notified us that it will not pursue further development under the Hansoh
Collaboration. This represented the conclusion of all required development activities and commitments under the terms
of the Hansoh Collaboration and we will retain exclusive rights globally for all three targets.

SILENCE THERAPEUTICS PLC

Financial Review
Revenue
Revenue for the year ended 31 December 2024 was £33.8 million (2023: £25.4 million). The increase was primarily due
to revenue associated with the Hansoh Collaboration. We recognized £19.2 million in 2024 related to the Hansoh
Collaboration resulting from a cumulative catch up as we have now completed all required obligations under the Hansoh
Collaboration. This was partially offset by a decrease in revenue from the Mallinckrodt Collaboration as we have
completed all required obligations under the Mallinckrodt Collaboration in 2024.
Cost of Sales
Cost of sales consists of research and development expenditure that is directly related to work carried out on revenue
generating contracts, which decreased to £9.2 million for the year ended 31 December 2024 (2023: £10.3 million). The
change is due to activity associated with our collaboration agreements, which fluctuate based on the timing of activities
and project progression.
Research and Development Expenses
Research and development costs for the year ended 31 December 2024 were £53.3 million as compared to £44.0 million
for the year ended December 31, 2023. Contract development costs increased by £5.4 million from 2023 as a result of
additional clinical trials and an increase in contract manufacturing activities for our proprietary programmes. Other costs
also increased by £3.0 million from 2023, mainly associated with associated with increased shipping and license fees.
General and Administrative Expenses
General and administrative expenses were £20.3 million for the year ended 31 December 2024 as compared to £20.6
million for the year ended 31 December 2023. The is largely consistent with the prior period.
Finance and Other Income (Expense)
Finance income and other income increased from £1.4 million for the year ended 31 December 2023 to £4.0 million for
the year ended, 31 December 2024. This primarily relates to accretion from U.S. Treasury Bills. For the year ended 31
December 2024 this was £3.5 million compared with £1.4 million for the same period in 2023.
Finance expense for the year ended 31 December 2024 was £0.1 million compared with £2.2 million in 2023. The
expense in 2023 primarily relates to foreign exchange losses of £2.1 million compared with gains in 2024 included in
finance and other income.
Taxation
During 2024 and 2023, we have recognized U.K. research and development tax credits of £10.5 million and £7.8 million,
respectively in respect of R&D expenditures incurred; the higher tax credit in current year due to an increase in R&D
expenditure compared to previous year. This amount was offset by tax charges in our foreign tax expense.
Liquidity, cash and cash equivalents
As of 31 December 2024, we had cash and U.S. treasury bills of £117.5 million ($147.3 million).
In 2024, the Group raised additional proceeds of £21,7 million ($27.7 million) before deducting £0.7 million ($0.9 million)
in placement agent fees and other expenses, from sales of ADSs under its Sales Agreement. On February 5, 2024, the
Group announced a private placement of 5,714,286 of the Group’s American Depositary Shares (“ADSs”), each
representing three ordinary shares, at a price of $21.00 per ADS, with new and existing institutional and accredited
investors (the “Private Placement”). The aggregate gross proceeds of the Private Placement was £95.4 million ($120.0
million) before deducting approximately £6.1 million ($7.7 million) in placement agent fees and other expenses. In 2024,

SILENCE THERAPEUTICS PLC

the Group received a £7.9 million ($10.0 million) milestone payment from the AstraZeneca Collaboration and achieved
another £1.6 million ($2.0 million) in milestone payments from the Hansoh collaboration.
Key performance Indicators (“KPIs”)
The Company is a development stage business and does not yet generate revenues or other operating cash inflows
from commercial sales. The Company therefore has primary KPI of cash and short-term investments.
Strategic objective: Availability of financial resources to progress the development of research and development
activities of the Company and its subsidiaries.
Key Performance Indicator: Year-end cash and U.S. treasury bills: £117.5 million (2023: £54.0 million).
Principal Risks
We constantly monitor and assess the overall risk of doing business in the biopharmaceutical industry and the particular
risks associated with our current activities and corporate profile. Having carried out a review of the level of risks the
Company and its subsidiaries is taking in pursuit of its strategy, the board of directors of the Company (the “Board”) is
satisfied that the level of retained risk is appropriate and commensurate with the financial rewards that should result
from the achievement of its strategy. The main risks have been identified as follows:

We will require additional financial resources to continue the ongoing development of our product candidates
and pursue our business objectives. If we are unable to obtain these additional resources when needed or on
acceptable terms, we may be forced to delay or discontinue our planned operations, including clinical testing
of our product candidates.
The approach we are taking to discover and develop drugs is novel and we may not be successful in our efforts
to identify or discover potential drug product candidates to bring into clinical trials.
If clinical trials of our product candidates fail to commence or, once commenced, fail to demonstrate safety and
efficacy to the satisfaction of regulatory authorities, or do not otherwise produce positive results, we may incur
additional costs or experience delays in completing, or ultimately be unable to complete, the development and
commercialisation of our product candidates.
We have a history of net losses and we anticipate that we will continue to incur significant losses for the
foreseeable future.
We face competition from other companies that are working to develop novel drugs and technology platforms
using technologies similar to ours. If these companies compete with us for limited manufacturing supplies, or
for animals critical for preclinical testing, or otherwise develop drugs more rapidly than we do or their
technologies, including delivery technologies, are more effective, our ability to successfully commercialise
drugs may be adversely affected.
We rely on third parties to conduct some aspects of our manufacturing, research and development activities,
and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of
research or clinical testing.
If we are unable to obtain or protect intellectual property rights related to our current or future product candidates,
we may not be able to compete effectively in our markets.
As part of our U.S. listing on Nasdaq, we no longer qualify as an “emerging growth company” as of .31 December
2024, and, as a result, we will no longer be able to avail ourselves of certain reduced reporting requirements
applicable to emerging growth companies.
As part of our U.S. listing on Nasdaq, the transition from foreign private issuer to U.S. domestic issuer status
effective from January 1, 2025, requires us to comply with the U.S. domestic reporting requirements under the
Exchange Act and will result in significant additional compliance activity and increase our costs and expenses.

SILENCE THERAPEUTICS PLC

Corporate Social Responsibility
Our vision is to transform peoples’ lives around the world by silencing diseases through our precision engineered
medicines whilst driving positive change for the communities around us. As part of this we are committed to corporate
social responsibility.
Social, Community & Human Rights
Our aim is to improve global health by bringing transformative treatments to adults and children in need, including for
rare diseases for which there are currently limited or no treatments. During 2024, Silence’s potential treatments
continued to progress:
Zerlasiran: presented positive results from the ALPACAR-360 Phase 2 study in ASCVD patients with high Lp(a).
Divesiran: presented positive interim results from the SANRECO Phase 1 study in PV patients.
We are committed to creating inclusive policies and equal opportunities for our current generation, while encouraging
the future generation of scientists who will deliver tomorrow’s medical breakthroughs.

Greenhouse Gas Report

Period

Year ended 31 December 2024

Year ended .31 December 2023

metric tons of CO2 equivalent
emissions

metric tons of CO2 equivalent
emissions
Estimated greenhouse gas emissions from
our own activities, including the
combustion of fuel and the operation of
our facilities

-
Estimated greenhouse gas emissions from
purchased electricity, heat, steam or
cooling for our own use.

120

112
Total estimated greenhouse gas
emissions

120

112
Intensity ratio: Total greenhouse gas
emissions per employee on the basis
of the average number of 116 full-
time equivalent employees during the
year ended 2024 (2023: 115)

1.03

0.97

We have used the most recent estimates provided by our energy supply partners to generate our disclosures of
emissions for the period. These include the purchase of electricity, heat, steam, or cooling. Standard emissions factors
from the “UK Government CHG Conversion Factors for Company Reporting 2024” guidance was applied in order to
estimate emissions. The group considers the intensity ratio of tonnes of carbon dioxide per full time equivalent
employees is a suitable metric for its operations.
Electricity usage at our leased facilities in the United States, Germany, and the United Kingdom drive the majority of our
gas emissions. The Group’s estimated electricity usage for the reporting period is 578,000 kWh (an estimated 120 metric
tons of CO2 equivalent emissions), with 12% of that estimated usage occurring in the United Kingdom (2023: 543,000
kWh).
As a matter of course, the group actively looks to minimise indirect areas of emissions by enabling remote working and
promoting online conferencing facilities to reduce business travel.

SILENCE THERAPEUTICS PLC

Employees
We are proud to say that in 2024 Silence maintained its ‘Great Place to Work’ status in the UK and Berlin and was
certified in the United States. We have focused on building a diverse and inclusive culture in which upward
communication and feedback is valued and encouraged. Silence recognizes that flexibility positively impacts employee
productivity, commitment, and loyalty and believes in trying to assist staff to achieve a good balance between their work
and home life.
We provide private medical insurance to all employees for acute medical conditions to cover full out-patient treatment,
therapies, mental health support, dentist and optician cashback and extra cancer cover as a taxable benefit.
We also provide several other health and wellbeing programmes to our employees. For example, we provide for all
employees to have a subscription to the app-based wellbeing programme called Headspace. We also provide an
Employee Assistance programme with the aim to give people access to 24/7 advice and help in personal and work-
related matters.
Environment
We are monitoring our production processes and investigating new ways to increase the efficiency and reduce the mass
intensity. In addition, we have issued company recommendations to reduce individual employee’s environmental impact
and better work-from-home practices.
Gender of Directors and Employees
As of 31 December 2024, we had 116 employees. Of these employees, 85 employees are engaged in research and
development activities and 31 employees are engaged in general and administrative activities. We have no collective
bargaining agreements with our employees and we have not experienced any work stoppages.
Diversity
Appointments within the Group are made on merit accounting to the balance of skills and experiences offered by
prospective candidates. Whilst acknowledging the benefits of diversity, individual appointments are made irrespective
of personal characteristics such as race, disability, gender, sexual orientation, religion or age.
A breakdown of the employment statistics on the basis of employees as at 31 December 2024 is as follows:
Gender Identity
female
male
non-binary
didn't disclose
total

Directors
0
4
0
0
4
Senior Leaders
8
9
0
0
17
Other employees
54
45
0
0
99
*Of the Directors, there is one executive director, that is considered both a director and an employee.
**Senior Leadership includes Department Heads and Vice Presidents.

Human Rights
The Group supports the UN Universal Declaration of Human Rights and recognises the obligation to promote universal
respect for and observance of human rights and fundamental freedoms for all, without distinction. The Group complies
with all applicable human rights laws.

SILENCE THERAPEUTICS PLC
16
Companies Act 2006, s.172 Compliance
The Company is required to provide information on how the directors have performed their duty under section 172 of
the Companies Act 2006 to promote its success, including how the interests of its stakeholders have been taken into
account in Board discussions and decision-making; stakeholders include:
Investors
The interests of its shareholders have been taken into account on a fair basis. This is described in more detail
in the Corporate Governance Report on page 23. The Company has a frequent and transparent dialogue with
its investors throughout the year. Meetings take the form of roadshows, investor conferences and one-on-one
dialogue as required.
Regulators
Good dialogue is maintained with regulatory agencies and the Board ensures our clinical trials are designed
appropriately to allow the maximum potential for our products in development.
Suppliers
The Company’s supply chain is crucial to the project work that is being undertaken; policies are in place to
identify suppliers with the right profile and capabilities. Good relationships are kept with suppliers; high
standards are expected in product and service, and the Company reciprocates by paying on a prompt basis,
within agreed terms. We meet with our significant suppliers regularly, monitoring the quality of products and
services on a constant basis to ensure that there is no negative impact or delays on our research programmes.
This ensures that the Company’s and our significant suppliers’ interests are aligned.
Employees
The Board has a good relationship with the Company’s employees. The Board maintains productive interactions
with employees. Appropriate remuneration and incentive schemes are maintained to align employees'
objectives with those of the Company. As a result, the Company has a high staff retention rate. More detail on
how the board takes into account the interests of employees can be found in the Remuneration Committee
report on page 32.
Community & Environment
Policies are being formulated with emphasis on matters like carbon footprint, for example holding virtual
meetings where possible rather than travelling between our sites in the U.K., Germany and U.S. Diversity in the
workplace is actively encouraged. The Company has policies on anti-slavery and anti-bribery which are actively
promoted.
The Board focuses on maintaining high standards of business conduct. The Company operates a Code of Business
Conduct and Ethics and provides mechanisms for whistle blowing and complaints.
The directors continue to review and improve on the Company’s engagement with its stakeholders.
The strategic report has been approved by the Board and is signed on its behalf by:
Craig Tooman
Chief Executive Office

SILENCE THERAPEUTICS PLC

Board of Directors
Our Board is comprised of five accomplished members, one Executive and four Non-Executive Directors.
Together, they bring highly valuable experience across a variety of relevant disciplines to effectively execute
our business plan.
Iain Ross
Chairman
Appointed April 2019
Iain Ross joined Silence as Chairman in April 2019. He previously served as Chairman at Silence from 2004 to 2010.
Mr. Ross has over 40 years’ experience in the international life sciences and technology sectors and has held significant
roles in multi-national companies including Sandoz, Hoffman La Roche, Reed Business Publishing and Celltech Group
plc. He has completed multiple financing transactions and has over 30 years’ experience in cross-border management
as a chairman and CEO. He has led and participated in eight Initial Public Offerings (IPOs) and has direct experience
of M&A transactions in Europe, the USA and the Pacific Rim.
Currently Mr. Ross serves as Executive Chairman of Oxford Biodynamics plc (LSE), Non-Executive Chairman of
ReNeuron Group and internationally holds other non-executive director roles.
Areas of Expertise
Corporate Strategy, M&A, Business Development and Governance

Craig Tooman
Executive Director
Appointed February 2022
Craig Tooman was appointed President, Chief Executive Officer and Executive Director of Silence in February 2022.
In this role, he has overseen the clinical progression of the lead program SLN360 to treat LP(a) and initiated the study
of SLN124 for polycythemia vera. He was promoted from his role as Chief Financial Officer of Silence which he held
since January 2021. He successfully raised over $200 million and shifted emphasis to the company’s Nasdaq listing.
Mr. Tooman has experience in the biopharmaceutical industry spanning more than 30 years, including 15 years of
experience as a public company CEO and CFO. Mr. Tooman served as CEO and Board Director of Aratana
Therapeutics, Inc., where his team successfully built an award-winning company for innovation, and ultimately
negotiated a merger with Elanco. Before Aratana, from 2005 to 2010, Mr. Tooman served as the CFO of Enzon
Pharmaceuticals, Inc. until its acquisition by Sigma Tau. Prior to that, at ILEX Oncology, he led the transformation of a
CRO into a successful proprietary pharma business before the $1.1 billion M&A initiative and integration of the
company with Genzyme Corporation. He has also held key positions at Pharmacia and Upjohn.
Mr. Tooman has served on seven pharmaceutical Boards and chaired the audit committees at four of those. He
currently serves on the Supervisory Board and chairs the Remuneration Committee of CureVac. He received a BA
degree in Economics from Kalamazoo College and studied at Waseda University in Tokyo as part of that program. He
earned his MBA in finance from the University of Chicago.
Areas of Expertise
Leadership, Global Commercialisation, Strategy, M&A, Business Development, Biotech build

SILENCE THERAPEUTICS PLC

Dave Lemus
Non-Executive Director
Appointed June 2018
Dave Lemus joined Silence as Non-Executive Director in June 2018.
At 31 December 2024, Mr. Lemus is currently on the board of directors of BioHealth Innovation, Inc. and miRecule Inc.,
where he also serves presently as Chief Operating Officer and Chief Financial Officer. Mr. Lemus was the Chief
Executive Officer of Ironshore Pharmaceuticals Inc., and prior to this, served as Medigene AG’s Chief Operating Officer
& Chief Financial Officer. Previously, Mr. Lemus was the Chief Executive Officer of Sigma Tau Pharmaceuticals, Inc.,
and was also Chief Financial Officer and Executive VP of MorphoSys AG for 13 years, taking the company public in
Germany’s first biotechnology initial public offering in 1999.
Mr. Lemus received an M.S. from the Massachusetts Institute of Technology and received a B.S. from the University of
Maryland. Mr. Lemus is a Certified Public Accountant in the United States.
Areas of Expertise
Drug Commercialisation, Strategic Partnerships, Corporate Financing,

James Ede-Golightly
Non-Executive Director
Appointed April 2019
James Ede-Golightly joined Silence as Non-Executive Director in April 2019.
Mr. Ede-Golightly is currently Chairman of Oxehealth Ltd, Oxeco Ltd and ORA Global Ltd. Among other directorships,
Mr. Ede-Golightly is also Non-Executive Director of Sarossa plc and Gulfsands Petroleum plc. Mr. Ede-Golightly was a
founder of ORA Capital Partners in 2006, having previously worked as an analyst at Merrill Lynch Investment Managers
and Commerzbank.
Mr. Ede-Golightly is a CFA Charterholder and holds an M.A. degree in economics from Cambridge University. In 2012,
he was awarded New Chartered Director of the Year by the Institute of Directors.
Areas of Expertise
Investment and Corporate Finance

Michael Davidson, MD
Non-Executive Director
Appointed January 2021
Dr. Michael H. Davidson joined Silence as Non-Executive Director in January 2021.
Dr. Davidson is Professor of Medicine and Director of the Lipid Clinic at the University of Chicago and also serves as
Chief Executive Officer of New Amsterdam Pharma. He is a leading expert in the field of Lipidology. He has conducted
over 1000 clinical trials, published more than 350 medical journal articles and written three books on Lipidology. His
research background encompasses both pharmaceutical and nutritional clinical trials including extensive research on
statins, novel lipid-lowering drugs, and omega-3 fatty acids. Dr. Davidson founded the Chicago Center for Clinical
Research, which became the largest investigator site in the United States and was acquired by Pharmaceutical Product
Development in 1996. Additionally, he founded Omthera Pharmaceuticals in 2008, which was acquired by AstraZeneca

SILENCE THERAPEUTICS PLC

in 2013 for $440M, and most recently, he was Founding CEO/CSO of Corvidia Therapeutics, which was acquired by
Novo Nordisk for up to $2.1B in 2020. In August 2020, he became the founding CEO of New Amsterdam Pharma based
in Amsterdam and Adventura, Florida. New Amsterdam Pharma was listed on the NASDAQ (NAMS) in November,
2022. He is also an Independent Director of Nasdaq-listed Tenax Therapeutics. And serves on the board of two private
biotech companies, Sonothera and NanoPhoria Bioscience.
Dr. Davidson is board-certified in internal medicine, cardiology, and clinical lipidology. He was President (2010-2011) of
the National Lipid Association, named as one The Best Doctors in America for the past 20 years and “Father of the
Year” by the American Diabetes Association, 2010.
Areas of Expertise
Lipidology and Clinical Development

SILENCE THERAPEUTICS PLC

Chairman’s Statement
Introduction
The Group’s strategy continues to be to maximize the potential of our proprietary mRNAi GOLD™ platform by
advancing a pipeline of both wholly owned and partnered programmes. Our wholly owned programmes focus and
leverage our internal expertise in specific areas with the most opportunity while our partnered programmes provide
collaboration for a broader reach and potential source for non-dilutive capital. We believe this business model balances
risk and creates more opportunities.
During the year, we made excellent progress advancing both our wholly owned and partnered portfolios.
mRNAi GOLD™ Proprietary Programmes
Divesiran for haematological diseases
Divesiran is our wholly owned siRNA product candidate in Phase 2 development for PV. Divesiran has the potential
to be the first-in-class siRNA in PV. PV is a rare myeloproliferative neoplasm - a type of blood cancer - characterized by
the overproduction of blood cells and platelets, often resulting in elevated HCT. Elevated HCT above 45-percent is
associated with a four-times higher rate of death from cardiovascular or thrombotic events. PV is associated with a
range of burdensome symptoms including fatigue, cognitive disturbance and pruritis and additionally, longer term can
transform to myelofibrosis and Acute Myeloid Leukemia. The aim of treatment is to maintain HCT less than 45%, a level
that is associated with a reduced incidence of thrombosis and cardiovascular-associated death. The current standard
of care includes repeated phlebotomies to reduce HCT and/or cytoreductive agents to reduce red blood cell production.
There are currently no approved therapies that specifically target red blood cells and HCT. PV is a rare disease affecting
approximately 150,000 in the U.S. and around 3.5 million worldwide.
Divesiran is administered subcutaneously and works by specifically binding to and inducing RNAi-mediated
degradation of mRNAs made from the TMPRSS6 gene. TMPRSS6 is a negative regulator of hepcidin, which is the main
hormone controlling iron homeostasis in the body. By silencing TMPRSS6 in PV patients, divesiran aims to increase
hepcidin production and release by liver hepatocytes, leading to the restriction of iron to the bone marrow and, thus,
reducing the excessive production of red blood cells, a process dependent on availability of iron.
In December 2024, we presented positive interim results from the Phase 1 portion of the SANRECO Phase 1/2
study of divesiran in PV patients at the ASH Annual Meeting. Interim results showed divesiran substantially reduced
phlebotomy requirements and lowered HCT levels following infrequent dosing in a range of PV patients. Divesiran has
been well tolerated to-date with no dose-limiting toxicities. In December 2024, we also announced the first subject has
been dosed in the Phase 2 portion of the SANRECO study which is currently underway. We anticipate full enrolment by
year-end 2025. The FDA has granted divesiran Fast Track and orphan drug designations for PV. In December 2024,
the European Commission (EC) granted divesiran orphan drug designation for PV in Europe.
SANRECO Phase 1/2 Programme
SANRECO is Phase 1/2 study with an open-label dose escalation phase followed by a randomized placebo
controlled and double-blind phase of divesiran in PV patients.
The Phase 1 portion of SANRECO is a 34-week, open-label study evaluating divesiran (3 mg/kg, 6 mg/kg and 9
mg/kg) administered subcutaneously every 6 weeks for four doses, with a 16-week follow-up period following the date
of the last administered dose in 21 PV patients. Key inclusion criteria include a PV diagnosis and a history of requiring
at least three phlebotomies in the last six months or five in the last year prior to screening. Patients are allowed to be
on stable doses of cytoreductive agents. Given the exploratory nature of this Phase 1 study, both well-controlled patients
- defined as those with HCT levels at 45% or less – as well as those with HCT levels greater than 45% at baseline on
current standard of care treatment were enrolled.
In December 2024, we presented positive interim results from the Phase 1 portion of the SANRECO Phase 1/2
study of divesiran in 19 PV patients at the American Society of Hematology (ASH) Annual Meeting. Interim results

SILENCE THERAPEUTICS PLC

showed divesiran substantially reduced phlebotomy requirements and lowered HCT levels following infrequent dosing
in a range of PV patients.

Interim results included 19 PV patients with a combined history of 79 phlebotomies prior to enrolment.
Following divesiran dosing, only five phlebotomies occurred during the 18-week treatment period – all were
in patients who entered the study with high baseline HCT levels (over 45%). Two phlebotomies occurred in
the 16-week follow-up period following the last administered dose.

Divesiran continues to be well tolerated to-date with no dose limiting toxicities.
The Phase 1 portion of the SANRECO study completed follow-up in February 2025. Phase 1 data presentations are
planned for medical congresses in 2025.
In December 2024, we also announced the first subject has been dosed in the Phase 2 portion of the SANRECO study
which is currently underway. The Phase 2 study is evaluating PV patients with baseline HCT <45% prior to dosing. We
anticipate full enrolment by year-end 2025.
Zerlasiran for cardiovascular disease
Zerlasiran is our wholly owned siRNA product candidate for high lipoprotein(a), also known as “Lp(a)”, a key
cardiovascular risk factor that is almost entirely genetically determined. This means that unlike other cardiac risk factors,
Lp(a) can’t be modified by diet or exercise. High Lp(a) is considered to affect up to 1.4 billion people worldwide, or
around 20% of the world’s population. It’s associated with a high risk of heart attack, stroke and aortic stenosis. You
need pharmacological intervention to manage high Lp(a) and currently there are no approved therapies that selectively
lower Lp(a). In clinical trials to-date, zerlasiran has shown the potential to address this major unmet need in
cardiovascular disease.
ALPACAR-360 Phase 2 Clinical Programme
In November 2024, we presented positive results from the ALPACAR-360 phase 2 study evaluating zerlasrian in
nmol/L at high risk of ASCVD events. This data was featured during the Late-Breaking
Science Session of the American Heart Association (AHA) 2024 Annual Meeting and simultaneously published in the
Journal of the American Medical Association (JAMA). Results showed that zerlasiran (300 mg every 16 weeks, 300 mg
every 24 weeks or 450 mg every 24 weeks) produced greater than 80% mean time-averaged placebo-adjusted
reductions from baseline in Lp(a) concentrations over 36 weeks. This is the first study to report time-averaged Lp(a)
analyses, which more accurately evaluates the effects of treatment over time, including intervals between doses.
Maximum Lp(a) reductions exceeded 90%. At the final visit, 60 weeks following initial drug administration, reductions in
Lp(a) persisted and no safety concerns emerged with infrequent dosing.
The clinical data we’ve generated to-date support our firm belief that zerlasiran is poised to be a major player in the
emerging Lp(a) space with multi-billion-dollar potential. During the year, we finalized the design for the Phase 3
cardiovascular outcomes study which we believe can further buildout zerlasiran’s competitive profile. We have met with
global regulatory agencies and received positive feedback on the Phase 3 programme. We are continuing to evaluate
partnership opportunities for this programme and will only initiate the Phase 3 cardiovascular outcomes study once a
partner is secured. Our priority is to ensure we maximize the value of this important asset for Silence shareholders and
patients.

SILENCE THERAPEUTICS PLC

mRNAi GOLD™ Partnered Programmes
AstraZeneca
We were pleased to have a third siRNA from our mRNAi GOLD platform enter the clinic in 2024 under our
AstraZeneca collaboration. We value this partnership very much and are proud of the programme we have been able
to advance together. We look forward to its further progress and the potential to earn additional milestones.
Hansoh
In December 2024, Hansoh Pharma opted not to pursue further development under our collaboration agreement to
develop siRNAs for three undisclosed preclinical liver targets using our mRNAi GOLD platform. Hansoh formerly had
options to license China region rights on two of the targets and global rights on the third target. All three programmes
have generated promising preclinical data, and we are evaluating them as part of our broader portfolio to determine
which ones we want to bring forward ourselves or potentially partner.

Great Place to Work certified
We are proud to say that in 2024 Silence maintained its ‘Great Place to Work’ status in the UK, Berlin and was
certified in the United States. We have focused on building a diverse and inclusive culture in which upward
communication and feedback is valued and encouraged. Silence recognizes that flexibility positively impacts employee
productivity, commitment, and loyalty and believes in trying to assist staff to achieve a good balance between their work
and home life.

Outlook
2024 was marked by strong clinical execution and pipeline advancement, highlighting the broad potential of our
mRNAi GOLD™ platform to silence disease causing genes. In 2025, we are prioritizing investment in programmes
targeting rare conditions where we believe we can deliver on clear unmet needs with first-in-class and/or best-in-class
siRNAs. We believe divesiran is a great example of this strategy and clinical commitment. We continue to believe in
zerlasiran’s potential, and the Silence team has done an excellent job designing what we believe is a highly differentiated
Phase 3 programme. There are very few cardiovascular assets in development that aim to treat an unmet medical
condition as large as the Lp(a) opportunity. We are hopeful we will secure the right partner to bring this very promising
programme forward. The decision not to initiate the zerlasiran Phase 3 outcomes study without a partner extends our
projected cash runway into 2027 and gives us flexibility to invest in our innovative pipeline while we continue partnering
discussions. Our ultimate goal is to maximize the value of our mRNAi GOLD™ platform for Silence stakeholders and
patients.

Iain Ross
Chairman

SILENCE THERAPEUTICS PLC

Corporate Governance Report
The Directors remain committed to maintaining high standards of transparency, ethics and corporate
governance.
What corporate governance standards does the Company follow?
In July 2018, the Board approved the application of The Quoted Companies Alliance (QCA) Corporate Governance
Code (the QCA Code). While the Company is no longer required to comply with the QCA code as the Company is no
longer listed on AIM, the Company has voluntarily continued to comply, where applicable, through the reporting period.
The QCA Code is a practical, outcome-oriented approach to corporate governance that is tailored for small and mid-
size quoted companies in the UK. The Board views this as an appropriate corporate governance framework for Silence
Therapeutics plc and consideration has been given below to each of the ten principles set out in the QCA Code.
How frequently does the Board meet?
The Board holds four scheduled meetings per year, aligned with quarterly management reporting; regular monthly Board
update calls and additional meetings and Board calls when circumstances and urgent business dictate. In the 12-month
period under review, there were 11 meetings. The Board meetings are scheduled to keep Board members fully updated
on business developments.

Type of meeting
Number of meetings
Board
11
Audit and Risk Committee
6
Remuneration Committee
4
Nomination Committee (1)
0
(1) During 2024, no new board members were recruited or selected.
All Board and Audit and Risk Committee and Renumeration Committee meetings were fully attended by the relevant
Directors throughout the year either in person or virtually. All Directors receive the agenda and Board papers in advance
of Board meetings to enable them to make an effective contribution. Between Board meetings, the Chairman maintains
regular informal contact with Non-Executive Directors. The Board continues to meet on a regular basis in order to review
progress and agree strategy.
The Board reviews the strategy and at each meeting evaluates the progress of the Company towards achieving its
annual objectives. It also analyses the risk of potential activities and monitors financial progress against budget.
How does the Board apply the ten principles set out in the QCA Code?
1. Establish a strategy and business model which promote long-term value for
shareholders
The Board has a clear strategy, which is set out in the Chairman’s statement on pages 20 to 22.
To support the execution of this strategy, the Board performs the following key tasks:
setting the Company’s values and standards;
approval of long-term objectives and strategy;
approval of revenue, expense and capital budgets and plans;
approval for therapeutic candidate progression through key development and clinical stages;
oversight of operations ensuring that adequate systems of internal controls and risk management are in place,
ensuring maintenance of accounting and other records, and compliance with statutory and regulatory obligations;

SILENCE THERAPEUTICS PLC

review of performance in light of strategy and budgets ensuring that any necessary corrective actions are taken;
review progress towards and consider options and terms of business development and corporate collaboration and
development deals;
approval of the annual report and financial statements, quarterly results, material contracts and major projects;
changes to structure, size and composition of the Board;
determining remuneration policy for the Directors and approval of the remuneration of the Non-Executive Directors;
and
approval of communications with shareholders and the market.
2. Seek to understand and meet shareholder needs and expectations
Contact with major shareholders has been principally maintained by the CEO and the Chairman during the reporting
period, and they have ensured that their views are communicated to the Board as a whole. The Board believes that
appropriate steps have been taken during the reporting period to ensure that the members of the Board, and in particular
the Non-Executive Directors, develop an understanding of the views of major shareholders about the Company.
Whilst we are aiming to hold our Annual General Meeting in June, a Notice of Annual General Meeting will be issued in
due course and will be available on our website. Separate resolutions will be provided on each issue so that they can
be given proper consideration. Proxy votes are counted and the level of proxies lodged on each resolution reported after
it has been dealt with by a show of hands.
3. Take into account wider stakeholder and social responsibilities and their implications for
long-term success
The Board considers the Company’s ability to help patients and their caregivers to be highly important and critical to the
long-term success of Silence. For more information on how the Company’s lead drug candidates, SLN124 and SLN360,
can help patients, refer to pages 7 to 10. Our sustainable development goals including goals related to community,
health and environment, are set out on pages 14 to 16.
4. Embed effective risk management, considering both opportunities and threats, throughout
the organisation
A Risk Register is maintained for regular review by the Audit and Risk Committee and the Board. Principal risks are set
out on page 13 where mitigating activities are also explained.
Additionally, the Audit and Risk Committee report on page 29 sets out how risks are reviewed.
5. Maintain the Board as a well-functioning, balanced team led by the Chairman
Currently the Board has a majority of Non-Executive Directors, consisting of one Executive and four Non-Executive
Directors. The Board’s composition is geared towards its current stage of development and priorities.
The skillsets of the Board include extensive knowledge of the pharmaceutical and biotechnology industries, strategic
consultancy and corporate finance.
The Nomination Committee is chaired by the Chairman of the Board, Iain Ross.
Details of each of the Directors’ experience and background are given in their biographies on pages 17 to 19.
The Chairman is responsible for leading the Board and ensuring its effectiveness and is responsible for the operational
management of the Company and implementation of Board strategy and policy.
The Board delegates certain activities to the Committees, with terms of reference which are available on the Company
website (www.silence-therapeutics.com). Membership of all three Board Committees comprises a Non-Executive Chair
and at least one other Non-Executive Director. All of the Board Committees are authorised to obtain, at the Company’s

SILENCE THERAPEUTICS PLC

expense, professional advice on any matter within their terms of reference and to have access to sufficient resources in
order to carry out their duties.

Board Structure
The Board Committee memberships are as follows:
Audit and Risk Committee
Dave Lemus (Chair)
James Ede-Golightly
Dr. Michael Davidson

Remuneration Committee
James Ede-Golightly (Chair)
Dr. Michael Davidson
Dave Lemus

Nomination Committee
Iain Ross (Chair)
James Ede-Golightly
Dr. Michael Davidson
Dave Lemus

6. Ensure that between them the directors have the necessary up-to-date experience, skills
and capabilities
The Board has delegated the tasks of reviewing Board composition, searching for appropriate candidates and making
recommendations to the Board on candidates to be appointed as Directors, to the Nomination Committee.
The Nomination Committee chair is held by the Chairman of the Company.
The main duties of the Nomination Committee are set out in its terms of reference and include:

regularly reviewing the structure, size and composition (including the skills, knowledge, experience and
diversity) required of the Board compared to its current position and making recommendations to the Board
with regard to any changes;

SILENCE THERAPEUTICS PLC

determining the qualities and experience required of the Company’s Executive and Non-Executive Directors
and identifying suitable candidates, assisted where appropriate by recruitment consultants;

formulating plans for succession for both Executive and Non-Executive Directors and in particular for the key
roles of Chair and Chief Executive Officer;

assessing the re-appointment of any Non-Executive Director at the conclusion of their specified term of office,
having given due regard to their performance and ability to continue to contribute to the Board in the light of
the knowledge, skills and experience required; and

assessing the re-election by shareholders of any Director, having due regard to their performance and ability
to continue to contribute to the Board in the light of the knowledge, skills and experience required and the
need for progressive refreshing of the Board.
With regard to the re-election of Directors, the Company is governed by its Articles of Association (the Articles). Under
the Articles, the Board has the power to appoint a Director during the year, but any person so appointed must stand for
election at the next Annual General Meeting. Any Director who has been a Director at each preceding two Annual
General Meetings and has not been appointed or re-appointed since, must retire from office at the next Annual General
Meeting.
The Director is then eligible to stand for re-appointment by the shareholders.
The annual performance evaluation for 2024, resulted in recommendations, which are being implemented by the Board,
to allocate more time at Board meetings to consider business development and opportunities to grow the business.
Silence is committed to diversity in all aspects of its mission and activities and at all levels of the organisation, including
its Board of Directors. The Board understands the value in having directors of diverse gender, race, and ethnicity, along
with varied skills, perspectives and experiences. We are constantly looking for opportunities to improve our diversity
and inclusion practices.
7. Evaluate Board performance based on clear and relevant objectives, seeking continuous
improvement
The Silence Therapeutics plc Board remains mindful that it needs to continually monitor and identify ways in which it
might improve its performance and recognises that board evaluation is a useful tool for enhancing a board’s
effectiveness.
A review of the CEO was initiated and concluded in December 2024. The CEO reviewed the performance of the CFO
for 2024. Any performance-related remuneration is determined by the Remuneration Committee and recommended to
the Board.
The Directors are responsible for evaluating the Chairman’s performance.
In conducting the formal annual evaluation, the Board undertakes a rigorous assessment of its own performance,
balance of skills, experience, independence, diversity (including gender diversity) and other factors relevant to its
effectiveness (and also that of its Committees) and the performance of its individual Directors. During 2023, the
Chairman and the Senior Independent Non-Executive Director, solicited the views of the other Directors, including the
completion by each Director of a confidential questionnaire in respect of the Board, the Audit and Remuneration
Committee and one specifically relating to the performance of the Chairman. The Senior Independent Non–Executive
Director had individual discussions with the Directors about the performance of the Chairman. In the case of the
Directors, all questionnaires were returned to the Senior Independent Non-Executive Director, who summarised the
overall assessment of each director.
Following the reviews, the Chairman, shared the observations with the other Directors at a Board Meeting in Q1 2024
during which an open feedback session was held in an executive session of the Non-Executive Directors. The individual
director evaluations were aimed to confirm that each Director continues both to contribute effectively and to demonstrate
commitment to the role (including the allocation of necessary time for preparation and attendance at Board and
Committee meetings and any other duties).
The results of the review were satisfactory overall, actions emerged which can be summarised as follows:

SILENCE THERAPEUTICS PLC

Strategy and Contingency Planning - As the Company expands its development pipeline, in-house
capabilities and corresponding operational infrastructure globally, it was agreed that there should be more emphasis
at Board meetings on strategic discussions and risk analysis and in addition that the annual strategy session for the
Board of Directors should be expanded to include external and professional input. External environment we are
likely to face should also be considered, both metric based and qualitative. Also, the Board and its Committees
should pro-actively consider, review and assess contingency scenarios on a regular basis.

Succession Planning - as the Company expands it was agreed that the Board needs to formalise its approach to
Board & Management succession planning in terms of skills, geography and diversity. The Chairman is committed
to lead this initiative in liaison with the CEO. In addition, be open and transparent around any concern about conflict
of interest if, and when, that exists.

Non-Executive Directors ongoing training and development and interaction with senior management -
Following a concerted effort led by the Chairman, this will be implemented to introduce a more structured approach
to the induction and broader development of Directors and interaction with the Senior Management on a more
frequent basis to enhance their knowledge and understanding of the business as it evolves. Further, each
Committee should be given the challenge to modernize, in light of changes in regulation and capital markets and
other external issues which many include potential changes in scope of the committee.
The Nomination Committee is responsible for succession planning and making recommendations to the Board in this
respect, as set out above.
8. Promote a corporate culture that is based on ethical values and behaviours
Ethical values and behaviours are important to the Company and the Company is dedicated to driving positive change
for communities around the world. The policies to implement this are explained on page 14.
9. Maintain governance structures and processes that are fit for purpose and support good
decision-making by the Board
The Board is supported by the Committees, explained above, in the task of maintaining good practice governance
processes and structures. Furthermore, the following governance matters support good decision-making by the Board.
Internal Controls and Risk Management
The Company has in place a system of internal financial controls commensurate with its current size and activities,
which is designed to ensure that the possibility of misstatement or loss is kept to a minimum. These procedures include
the preparation of management accounts, variance analysis, controls in place for one-off accounting items and other ad
hoc reports. In 2024 the Group engaged EisnerAmper as consultants to test ICFR (Internal controls over financial
reporting). As a result, the Group was able to build up of evidence from an internal control perspective and allow
management and external auditors to attest over the ICFR as required under the Sarbanes-Oxley Act 2002.
Risks throughout the Company are considered and reviewed on a regular basis. Risks are identified and mitigating
actions put into place as appropriate. Principal risks and uncertainties identified are set out in the strategic report on
page 13.
Internal control and risk management procedures can only provide reasonable and not absolute assurance against
material misstatement.
Financial and Business Reporting
The Board seeks to present a balanced and understandable assessment of the Company’s position and prospects in
all quarterly, full year and price-sensitive reports and other information required to be presented by statute. The Board
receives a number of reports to enable it to monitor and clearly understand the Company’s financial position. The
Company maintains a Disclosure Policy to enhance the process for ensuring that price-sensitive information is identified
effectively and all communications with the market are released in accordance with expected timescales.

SILENCE THERAPEUTICS PLC

Conflicts of Interest
Under the Articles of Association, the Directors may authorise any actual or potential conflict of interest a Director may
have and may impose any conditions on the Director that are felt to be appropriate. Directors are not able to vote in
respect of any contract, arrangement or transaction in which they have a material interest and they are not counted in
the quorum. A process has been developed to identify any of the Directors’ potential or actual conflicts of interest.
This includes declaring any new conflicts at the start of each Board meeting.
Board Advice
All the Directors have access to the advice and services of the Company Secretary, who is responsible for ensuring that
Board procedures and applicable regulations under the Company’s Articles of Association or otherwise are complied
with. Each Director is entitled, if necessary, to seek independent professional advice at the Company’s expense. The
Company maintains Directors’ and officers’ liability insurance.
10. Communicate how the company is governed and is performing by maintaining a dialogue
with shareholders and other relevant stakeholders
Contact with major shareholders is principally maintained by the Chairman and CEO, to discuss governance and other
matters directly with major shareholders, both private and institutional.
The Company uses its corporate website (www.silence-therapeutics.com) to communicate with institutional
shareholders and private investors, and the website also contains the latest announcements, press releases, published
financial information, current projects and other information about the Company. The annual report which includes the
financial statements is a key communication document and is available on the Company’s website.
Iain Ross
Chairman

SILENCE THERAPEUTICS PLC

Audit and Risk Committee Report
Commensurate with Silence’s Nasdaq listing allowing substantially greater investor access will be the Committee’s
heightened focus on all aspects related to company financings, internal controls and additional financial reporting
requirements.

Dave Lemus
Chair of the Audit and Risk Committee
Who are the members and who do they interact with?
Dave Lemus is Chair of the Audit and Risk Committee.
Dave currently also serves as audit committee chair of Sorrento Therapeutics, Inc. (Nasdaq: SRNE), and previously
served on multiple public and private company boards as a non-executive board member in his more than 25 years of
experience in the biopharmaceutical industry. Most recently he was CEO of Ironshore Pharmaceuticals, Inc., and has
been previously a CEO, COO and CFO in several public and private companies in the U.S and in Europe. Dave is also
a Certified Public Accountant in the USA.
In addition to Dave, the members of the committee comprise James Ede-Golightly and Dr. Michael Davidson. The
Committee met six times during 2024, including prior to results announcements.
The Committee interacts primarily with Silence management, external auditors, and internal audit consultants.
What does the Audit and Risk Committee do?

Monitors the integrity of the Company’s financial and narrative reporting

Monitors enterprise and systemic risks

Monitors the company’s fraud risk mitigation and whistleblower results

Reviews accounting policies and key estimates and judgements

Reviews the appropriateness and completeness of the internal controls

Makes recommendations to the Board, to be put to shareholders for approval at the Annual General Meeting, in
relation to the appointment, re-appointment and removal of the Company’s external auditors

Meets with the external auditors, ensuring that they report to it on all relevant matters to enable the Committee to
carry out its oversight responsibilities
How does the Committee monitor the Company’s financial reporting?
The Committee monitors the integrity of the Company’s financial statements, preliminary announcements and any other
formal announcements relating to the Company’s financial performance. In 2024, the Committee reviewed the 2023
annual report and the 2024 interim announcements. The Committee reviews and challenges where necessary any
changes to, and the consistency of, accounting policies, advising whether the Company has followed appropriate
accounting standards and made appropriate estimates and judgements (notably in respect to the adoption of any new
accounting pronouncements, the accounting of the partnership agreements and financings, and the impairment of
investments in subsidiaries), taking into account the views of the external auditors, the going concern assumption and
all material information presented with the financial statements.

SILENCE THERAPEUTICS PLC

What does the Committee do to review risks?
To assess the appropriateness and completeness of internal controls, the Committee reviews changes to the detailed
risk matrix which identifies high level control issues classified as critical under the Company’s risk matrix that require, or
are subject to, remedial action. The Committee considers whether the necessary actions are being taken to remedy any
significant failings or weaknesses.
Is there an internal audit function?
At present the Company does not have an internal audit function. Given the Nasdaq listing and recent transition to a US
domestic large accelerated filer, the Company is required to be compliant with additional Sarbanes-Oxley requirements
in 2024. This initially was achieved by in-house initiatives supported by external specialists. However, the Committee
will review the need for an internal audit function at least annually. In 2024, EisnerAmper was engaged as the Company’s
internal audit consultants used to review and test the ICFR (Internal controls over financial reporting). As a result, the
Group was able to acquire sufficient evidence from an internal control perspective and allow management and external
auditors, PricewaterhouseCoopers LLP, to attest over the ICFR as required under the Sarbanes Oxley Act 2002.
Who are the external auditors and how long have they been appointed?
PricewaterhouseCoopers LLP were appointed as the external auditors in 2014. The Committee reviews industry
comparables for audit services and evaluates the overall service provided by the external auditors each year. Having
reviewed the auditors’ independence and performance, the Committee is recommending that PricewaterhouseCoopers
LLP be re-appointed as the Company’s auditors at the next Annual General Meeting.
How does the Audit and Risk Committee assess the effectiveness of the external audit
process?
The Committee oversees the relationship with the external auditors, including approval of their remuneration, approval
of their terms of engagement, annual assessment of their independence and objectivity, taking into account relevant
professional and regulatory requirements, and the relationship with the auditors, as a whole, including the provision of
any non-audit services. The breakdown of fees between audit and non-audit services is provided in note 5 to the financial
statements. The auditors prepare an Audit Plan for the audit of the full year financial statements, which was presented
to the Committee and discussed in November 2024. The Audit Plan sets out the scope of the audit, areas to be targeted
and the audit timetable. Following the audit, the auditors present their findings to the Committee for discussion. The
Committee has ongoing discussion throughout the year with the external auditors. The Committee chair also provides
feedback at the conclusion of the external audit.
Review of Accounting and Financial Reporting Matters and Matters of Significance and
Judgement
The Committee received reports from management and the external auditors setting out the significant accounting and
financial reporting matters and judgements applicable to the following key areas. Following discussion and challenge,
the Committee reviewed management's conclusions on certain significant company accounting policies, which included
but were not limited to:
R&D costs related to CROs including associated accruals and prepayments
In determining the R&D expense in relation to contract research organisations (CROs) management have estimated the
total percentage of completion of each contract to date and included consideration of future costs to be incurred. These
estimates have also been used in determining accruals and prepayments at the year end.

SILENCE THERAPEUTICS PLC

Accounting for Revenue (collaboration agreements)
In determining the revenue recognised for collaboration agreements, management have calculated the revenue
recognised for the period based on the percentage of completion of each performance obligation, by determining the
proportion of costs incurred to date in comparison to the total expected costs (both internal and external).
Carrying value of the investment in Silence Therapeutics GmbH (to parent company)
Different methodologies can be used to determine the carrying value of this investment. In determining the carrying
value of Silence Therapeutics plc’s investment in Silence Therapeutics GmbH management assessed it as being based
on its estimated “value in use” (which utilizes an NPV methodology). In doing this the Company has had to estimate the
value and timing of future milestone cash inflows, which is however a standard industry practice.
Through constant communication and interaction with management and the Company’s auditors, the Audit and Risk
Committee aims to ensure appropriate corporate compliance with all accounting, internal controls, risk management
and financial reporting requirements and in order to best ensure the Committee is carrying out its oversight
responsibilities to the fullest extent possible.

Dave Lemus
Chair of the Audit and Risk Committee

SILENCE THERAPEUTICS PLC

Remuneration Committee Report
Having the right team to execute on an internationally competitive strategy in the fast-moving field of RNAi is
a key priority for the Board and the Company.
James Ede-Golightly
Chair of the Remuneration Committee
Dear Shareholder,
On behalf of the Remuneration Committee (the “Committee”), I am pleased to present our Directors’ remuneration report
for the year ended 31 December 2024.
Having the right team to execute on an internationally competitive strategy in the fast-moving field of RNAi is a key issue
for the Board and the Company. Craig Tooman has served as our President, Chief Executive Officer and as a member
of our board of directors since February 2022. Craig has experience in the biopharmaceutical industry spanning more
than 30 years, including 15 years of experience as a public company CEO and CFO. In February 2022 we also appointed
Rhonda Hellums as our Chief Financial Officer. Rhonda has over 25 years of corporate finance, accounting, strategic
planning, M&A, treasury management, investor and public relations experience, largely in the biopharmaceutical
industry. Though she is not a U.K director, she sits in on all board meetings.
We continue to deliver a remuneration programme that rewards both achievement of short-term goals and fulfilment of
our longer-term objectives, linked with the ultimate exploitation of our platform and its application in generating novel
RNAi medicines. We recognise the need to retain and motivate Executive Directors and the senior management team
and avoid making remuneration decisions solely based on shorter-term volatility. Accordingly, we include two
performance-based elements in our remuneration programme: a shorter-term annual bonus programme, with payment
amounts based on the previous year’s achievement against pre-set goals for that year; and a longer-term equity-based
programme of share options, vesting over four years and directed towards the achievement of substantial, longer-term
strategic objectives. The short-term programme and the long-term incentive programme are providing a balance
designed to incentivise Executive Directors and senior management to work toward achievement of the corporate
strategy.
During the year, share options were awarded to Craig Tooman; vesting dates for these options are detailed later in this
report. This remuneration policy has the intention of ensuring that Silence is in line with biotech industry best practices.

James Ede-Golightly
Chair of the Remuneration Committee

SILENCE THERAPEUTICS PLC

Directors’ Remuneration Policy

This part of the Remuneration Report sets out the Remuneration Policy and has been prepared in accordance with the
Large and Medium-sized Companies and Groups (Accounts and Reports) (Amendment) Regulations 2013, the
Companies (Miscellaneous Reporting) Regulations 2018, and the Companies (Directors’ Remuneration Policy and
Directors’ Remuneration Report) Regulations 2019.

The remuneration report sets out the Directors’ remuneration policy approved by a binding vote of shareholders on 17
May 2024 and which took effect on that date. Thereby, as intended the remuneration policy will remain in effect from
the date of approval and apply for a maximum period of three years (or until a revised policy is approved by
shareholders). The Remuneration Policy is unchanged this year, and as such is not subject to a shareholder vote.

The scenario charts have been updated to reflect the intended application of the approved policy for the 2025 financial
year and references to prior financial years have been updated where appropriate to aid understanding. A copy of the
shareholder-approved policy (including the scenario charts for the 2024 financial year) is in this Annual Report and
Financial Statements for the Year Ended 31 December 2024, which is available on the Company’s website.

The policy is designed to align to the Company’s strategy and business model and to reflect the Committee’s
remuneration philosophy, as summarised below.

Philosophy: Support value creation for shareholders over the longer term and create alignment with shareholders

Fixed Remuneration
Variable Remuneration
Element
Base Salary
Benefits
Pension
Annual Bonus
EIP
How it is influenced by
the remuneration
philosophy
Assessed with
reference to industry
compensation
benchmarks
Assessed with
reference to industry
compensation
benchmarks
Assessed with
reference to industry
compensation
benchmarks
Set considering industry
benchmarking data and
consistent with positions
held.
The more significant
element of the package
linked to longer-term share
performance.
Determined by corporate
and individual targets that
support Silence’s annual
goals and its overall
strategy.
Under the Silence
Therapeutics plc 2024
Equity Incentive Plan with
Non-Employee Sub-Plan
and CSOP Sub-Plan (the
“EIP”), equity awards, can
be issued with performance
and/or time based criteria.

In developing its policy, the Committee has regard to the policy for remuneration of employees across the
Company. The Directors’ remuneration policy was set considering the pay and conditions for other employees and the
Committee does not engage in a wider consultation with employees on the policy. Remuneration across the Company
is implemented in the following ways:

All employees are rewarded with a remuneration package that includes certain key benefits such as life assurance,
private medical insurance, 401(k) matching, access to pension benefits (or cash in lieu), and eligibility to receive a
bonus. All employees are eligible to participate in Silence’s EIP. Internal reviews are carried out to ensure that
levels of remuneration for all key employees are up to date and competitive within the sector.

The bonus arrangements for our Executive Directors and employees are designed to reward performance, and all
individuals work towards challenging corporate and individual goals.

In setting the remuneration policy for Directors, the pay and conditions of other employees are taken into account,
including any base salary increases awarded. The Committee is provided with data on the remuneration structure
for management level tiers below the level of Executive Director and uses this information to ensure consistency of

SILENCE THERAPEUTICS PLC

approach throughout the Company. The views of shareholders expressed in respect of Directors’ remuneration
were considered when formulating the Directors’ remuneration policy. The remuneration of senior executives below
Board level is reviewed by the Committee on an annual basis. The remuneration packages of these executives are
broadly consistent with the policy outlined above, with the overall impact of the role and the individual being
considered as well as relevant market comparative data, save that lower bonus percentages and lower share option
opportunities are applicable.

Remuneration Policy Table

The table in the following pages sets out, for each element of pay, a summary of how remuneration is structured and
how it supports the Company’s strategy.

Executive Directors
Purpose and Link

Operation
Maximum Opportunity
Performance Metrics
Base Salary
To attract and retain
executives of the highest
calibre who are capable
of delivering the
Company’s strategic
objectives, reflecting the
individual’s experience
and role within the
Company.
Base salary is designed
to provide an appropriate
level of fixed income to
avoid an over-reliance on
variable pay elements
that could encourage
excessive risk taking.
The Committee aims to set base salary at
levels that are broadly aligned with the mid-
points for equivalent roles in comparable
global companies, adjusted to reflect
Company size and complexity.
Salaries are normally reviewed annually,
and changes are generally effective from 1
January.
The annual salary review of the Executive
Directors takes into consideration a number
of factors, including, but not limited to:

business performance;

salary increases awarded to the
overall employee population;

skills and experience of the
individual over time;

scope of the individual’s
responsibilities;

changes in the size and
complexity of the Company;
market competitiveness and UK, European
and US market practice; and the underlying
rate of inflation.
Executive Director level salaries are
determined considering industry
benchmarking data.
Base salary increases are awarded at the
discretion of the Committee; however,
salary increases will normally be no
greater than the inflationary pay rises
awarded to the wider workforce.
Executive Director level salaries are
approved by the Committee in line with
corporate performance and are
consistent with the role currently being
undertaken by the individual.

Where there has been a change in the
role or, if the individual is new to the role,
initial base salary may be set at a lower
level and/or future increases could be
higher. Subsequent demonstration of
strong performance may also result in a
salary increase that is higher than that
awarded to the wider workforce.

No formal metrics, although any
increases take account of
Company performance and
Executive Director appraisal

Benefits
Benefits in kind offered to
Executive Directors are
provided on a market-
competitive basis, to
assist with their
recruitment and
retention.
The Company aims to offer benefits that
are in line with market practice.

The main benefits currently provided
include private health insurance, dental, life
insurance and retirement plan. The
Company may make a cash payment to
provide a gross up where penalty taxes are
There is no defined maximum value for
benefits, but the Committee will consider
the aggregate value of any such benefits
when determining what should be
offered.
Not performance related.
No claw-back will be applied in
relation to benefits.

SILENCE THERAPEUTICS PLC

payable under section 280G of the US
Internal Revenue code of 1986, as
amended in connection with a change of
control. The Committee will consider
whether this is appropriate taking into
account the circumstances of the
transaction.

In addition, the Company will pay for (i) the
preparation and submission of annual tax
returns in the UK and USA up to a
maximum of USD$10,000 per year, and (ii)
reasonable attorney’s fees for the review of
an Executive Director’s employment
agreement and related documents, up to a
maximum of USD$10,000.

Under certain circumstances the Company
may offer relocation allowances or
assistance.

Travel, accommodation and any
reasonable business-related expenses
(including tax thereon) may be reimbursed.
Executive Directors may become eligible
for other benefits in future where the
Committee deems it appropriate. Where
additional benefits are introduced for the
wider workforce, Executive Directors may
participate on broadly similar terms.

Executive Directors are eligible to
participate in the Company’s all-employee
share plans from time to time on the same
terms as other employees in the jurisdiction
in which they are engaged.
Pensions
The Company aims
-
competitive retirement
benefits, as a retention
tool and to reward
sustained contribution.
The Company operates a defined
contribution scheme and all employees,
participate. Payments are made directly to
a nominated pension scheme or, where
payments are made in cash, delivered
monthly through payroll.
Cash payments in lieu of pension
contributions may be made.
Employee contributions are matched two-
fold by employer contributions up to a
maximum employer contribution of 10%.
Employees may contribute more than 5%
themselves, but the Company will not
provide any further employer
contributions above this level.
Not performance related.

No claw-back will be applied in
relation to pensions.
Annual Performance Bonus
An annual cash bonus
rewards the achievement
of objectives that support
the Company’s corporate
Objectives are agreed with the Committee,
and the Board, at the start of each financial
year although the Committee retains the
discretion to amend objectives during the
Annual cash bonuses have a target of up
to 60% of base salary and a maximum
payout for “stretch” performance of up to
100% of base salary for the Executive
Directors.
Corporate goals typically include
development of pipeline and
platform, partnering successes,
revenue generation, strengthening
of intellectual property and control

SILENCE THERAPEUTICS PLC

goals and delivery of the
business strategy.
year if it considers that objectives are no
longer appropriate.

Different performance measures and
weightings may be used each year, as
agreed with the Committee, to consider
changes in the business strategy.

Bonuses are paid at the discretion of the
Committee.

The Committee considers overall corporate
performance and individual performance
when determining the final bonus amount
to be awarded and the Committee may
adjust any formulaic outcomes
accordingly. A deferral period may be
applied to bonuses.

Bonuses are normally paid in cash (but
may be paid in the form of an equity
award).

The Committee may, in appropriate
circumstances, override the formulaic
outcome to amend the bonus payout or
provide for an additional bonus payment,
should this not, in the view of the
Committee, reflect overall business
performance or individual contribution or in
connection with a corporate transaction
such as a change of control. If the
Committee provides for additional bonus
payments, the Committee has the
discretion to set the terms and value of
such bonus payment.

Executive Director level bonuses are
approved by the Board in line with
corporate performance and are
consistent with the role currently being
undertaken by the individual.
The Board can exercise discretion in
setting contractual target bonus rates for
new Executive Directors above 60%, with
discretion exercised with respect to total
compensation.

The bonus is performance based and the
final payout is entirely at the discretion of
the Company.

The Committee may, in appropriate
circumstances, waive the maximum
target bonus opportunity for Executive
Directors where an additional bonus
payout is made to reflect overall business
performance, individual contribution or
the achievement of separate targets,
such as the completion of a transaction.

of cash expenditure, although the
Committee has the discretion to set
other targets.

Individual goals set are specific,
Company’s longer-term strategy.

The Committee may, in appropriate
circumstances, disapply any
performance measures or award a
bonus without such performance
measures or apply different
performance criteria, such as the
completion of a transaction, should
they not, in the view of the
Committee, reflect overall business
performance or individual
contribution.

The amount of erroneously
awarded compensation resulting
from an accounting restatement
due to the material noncompliance
with any financial reporting
requirement under United States
securities laws will be subject to
clawback under the Company’s
clawback policy.
Equity Based Awards (EIP or any successor equity incentive plan)
The Remuneration
Committee believes that
a key component of the
overall remuneration
package is the provision
of equity awards to
senior executives
through an EIP, which is
designed to develop a
culture which encourages
strong corporate
performance on an
absolute and relative
EIP awards granted to Executive Directors
have typically taken the form of market
value options vesting over time, although
different forms of awards may also be
granted in accordance with the EIP
rules. The Committee may also vary the
vesting schedule of awards as it considers
appropriate.

The Committee has discretion to decide
whether and to what extent any deferral or
holding period applies to awards or to the
There is no defined maximum opportunity
under the EIP. The value of Executive
Director awards under the EIP are
approved by the Committee and reflect
the role, duties and responsibilities
currently being undertaken by the
individual.

The Committee can exercise discretion
when setting the value of EIP awards for
new Executive Directors taking into
account such Executive Director’s total
compensation package.
Vesting of EIP awards is generally
subject to continued employment
and may also be subject to the
achievement of performance
conditions aligned with the
Company’s strategic plan. Whether
performance measures shall apply,
and if so, their weightings and the
period over which performance is
tested will be determined by the
Committee.
The Committee has the discretion
to utilise differing types of
performance criteria, measures and

SILENCE THERAPEUTICS PLC

basis to align with
shareholder interests.
shares acquired following the vesting of
awards.

With the approval of the Company’s
shareholders, the Committee may
unilaterally modify the terms of share
options, in particular to reprice underwater
options to provide for a lower exercise
price.

The Committee seeks to establish equity-
based remuneration competitive to that
offered by a set of comparable
companies with whom the Company may
compete for talent.

performance periods for future
option grants, should it believe they
are more relevant.
The Committee may adjust the
formulaic EIP outcome to ensure it
takes account of any major
changes to the Company (e.g. as a
result of M&A activity) and is a fair
reflection of the underlying financial
performance of the Company over
the performance period.
The Committee has flexibility to
vary the mix of measures or
introduce new measures for each
subsequent award taking into
account business priorities at the
time of grant. The Committee may
amend, relax or waive performance
conditions if it considers that they
have become unfair or impractical.
This will help ensure that vesting
reflects overall Company
performance during the period.
Further details, including the
vesting terms and any performance
targets attached to the EIP in
respect of each year, will be
disclosed in the relevant Annual
Report on Remuneration.
The amount of erroneously
awarded compensation resulting
from an accounting restatement
due to the material noncompliance
with any financial reporting
requirement under United States
securities laws will be subject to
clawback under the Company’s
clawback policy.

Chair and Non-Executive Directors
Purpose and Link

Operation
Maximum opportunity
Performance Metrics
Cash Fees
Set at a level that is
sufficient to attract and
retain high-calibre non-
executives who contribute

Non-Executive Directors receive an annual retainer
paid in cash, comprising a base fee plus additional
fees for Committee Chairpersonship or membership.

Such fees are set based on peer group comparator
data.

When reviewing fee levels,
account is taken of market
movements in the fees of Non-
Executive Directors, Board
Committee responsibilities and
ongoing time commitments.

Not performance related.
No claw-back applies in relation
to fees.

SILENCE THERAPEUTICS PLC

Non-Executive Directors who participate and serve on
any membership committee or advisory board of or for
the Company may also receive a retainer paid in cash
annually or for each meeting attended. Such fees are
set based on peer group comparator data.
The Chair’s fee is reviewed annually by the Committee
(without the Chair present). Fee levels for the Non-
Executive Directors are determined by directors upon
the recommendation of the Committee.

When reviewing fee levels, account is taken of market
movements in fee levels, Board committee
responsibilities, ongoing time commitments and the
general economic environment.

In exceptional circumstances, if there is a temporary
yet material increase in the time commitments for Non-
Executive Directors, the Board may pay additional fees
to recognise that additional workload.
Benefits
Set at a level that is
sufficient to attract and
retain high-calibre non-
executives who contribute
to
the business.

Non-Executive Directors do not receive any benefits in
connection with their roles other than Company life
insurance and reimbursement of travel costs for
attendance at Board meetings. This may be reviewed
in the future.
When reviewing benefits,
account is taken of market
movements in the fees of Non-
Executive Directors, Board
Committee responsibilities and
ongoing time commitments.

Not performance related.
No claw-back applies in relation
to benefits.

Equity Based Awards
Set a level that is sufficient
to attract and retain high-
calibre non-executives who
contribute to the business.

Non-Executive Directors may receive equity awards
under the EIP (or options, share appreciation rights,
restricted shares, restricted share units or such other
form as may be permitted by any other equity incentive
plan operated by the Company from time to time),
with careful consideration being made with respect to
ensuring their independence. The Committee may, in
its sole discretion, provide for deferred settlement of
RSUs awarded to a Non-Executive Director.
With the approval of the Company’s shareholders, the
Committee may unilaterally modify the terms of share
options, in particular to reprice underwater options to
provide for a lower exercise price.

There is no maximum award
level for equity awards to Non-
Executive Directors.
The size of the equity awards is
determined by the full Board,
upon recommendation of the
Committee.
When reviewing equity-based
awards, account is taken of
market movements in the fees
of Non-Executive Directors,
Board Committee
responsibilities and ongoing
time commitments.

Not performance related.
No claw-back applies in relation
to Non-Executive Director
equity-based awards.

SILENCE THERAPEUTICS PLC

Notes to the policy table

Legacy arrangements

For the duration of this policy, the Company will honour any commitments made in respect of current or former directors
before the date on which either: (i) the policy becomes effective; or (ii) an individual becomes a director, even when not
consistent with the policy set out in this report or prevailing at the time such commitment is fulfilled, in each case subject
to the terms of any prior policy in place at the time such awards or commitments were granted or made, if applicable.

Performance conditions

The choice of annual bonus performance metrics reflects the Committee’s belief that any incentive remuneration should
be appropriately challenging and tied to the delivery of key strategic objectives intended to ensure that Executive
Directors are incentivised to deliver across a range of objectives for which they are accountable. The Committee has
retained flexibility on the specific measures which will be used to ensure that any measures are fully aligned with the
strategic imperatives prevailing at the time they are set.

The bonus targets for the forthcoming year will be set out in general terms, subject to limitations with regards to
commercial sensitivity. The full details of the targets will be disclosed when they are in the public domain and are no
longer considered commercially sensitive.

Where used, performance conditions applicable to EIP awards (or other equity incentive plans operated by the Company
from time to time) will be aligned with the Company’s objective of delivering superior levels of long-term value to
shareholders. Prior to each award, the Committee has flexibility to select measures that are fully aligned with the strategy
prevailing at the time awards are granted.

The Committee will review the calibration of targets applicable to the annual bonus, and the EIP in years where
performance measures apply, annually to ensure they remain appropriate and sufficiently challenging, taking into
account the Company’s strategic objectives and the interests of shareholders.

Recovery and withholding

On 8 November 2023, the board of directors of the Company adopted a new incentive compensation recoupment policy
providing for the Company’s recoupment of recoverable incentive compensation that is received by certain executive
officers of the Company under certain circumstances. Such clawback policy is designed to comply with, and shall be
interpreted to be consistent with, Section 10D of the Exchange Act, Rule 10D-1 promulgated thereunder and Nasdaq
Listing Rule 5608.

The Committee retains the discretion to update or amend the clawback policy from time to time in order to maintain
compliance with applicable laws, regulatory requirements and best practice from time to time.

Differences in remuneration policy between Executive Directors and other employees

The overall approach to reward for employees across the workforce is a key reference point when setting the
remuneration of the Executive Directors. When reviewing the salaries of the Executive Directors, the Committee pays
close attention to pay and employment conditions across the wider workforce and in normal circumstances (excluding
promotions) the increase for Executive Directors will be no higher than the average increase for the general workforce.

SILENCE THERAPEUTICS PLC

The key difference between the remuneration of Executive Directors and that of our other employees is that, overall, at
senior levels, remuneration is increasingly long-term, and ‘at risk’ with an emphasis on performance-related pay linked
to business performance and share-based remuneration. This ensures that remuneration at senior levels will increase
or decrease in line with business performance and provides alignment between the interests of Executive Directors and
shareholders.

Discretions retained by the Committee

The Committee will operate annual bonus arrangements and the EIP according to their respective rules (if any) and in
accordance with any applicable legislation where relevant.

The Committee retains discretion, consistent with market practice, over a number of areas relating to the operation and
administration of these arrangements and the policy in general. This includes, but is not limited to, the following:

The participants in incentive arrangements;

The timing of any awards or payments;

The size of any awards or payments and the vehicle with which they are delivered;

The treatment of outstanding awards on a change of control or other corporate events;

The treatment of leavers based on the rules of the plan (where applicable), the internal policies of the
Company and appropriate treatments described therein;

Adjustments in certain circumstances (such as a rights issue, corporate restructuring or payment of a special
dividend);

The applicability and selection of performance measures and targets applying each year;

Any adjustments to performance measures and targets to reflect changes in circumstances that are expected
to have a material impact on the intended difficulty of the targets; and

Whether malus and/or clawback shall be applied to any award in the relevant circumstances and, if so, the
extent to which it shall be applied.

The Committee retains the discretion to award ad hoc bonus payments in addition to annual bonus, or to adjust annual
bonus and/or equity incentive awards, if an event or circumstance occurs which means outcomes do not reflect the
overall business performance, individual contribution or external factors which impacts the workforce such as in
connection with a corporate event such as a change of control. Any use of the above discretion would, where relevant,
be explained in the Annual Report on Remuneration and may, as appropriate, be the subject of consultation with the
Parent Company’s major shareholders.

The Committee will consider formulaic outcomes of incentive arrangements and will have the discretion to override
these where appropriate, taking into account a holistic view of performance and/or wider stakeholder experience, such
as in connection with a corporate event such as a change of control. Any use of the above discretions would, where
relevant, be explained in the annual report on remuneration and may, as appropriate, be the subject of consultation with
the Company’s major shareholders.

The Committee may make minor amendments to the policy (for regulatory, exchange control, tax or administrative
purposes or to take account of a change in legislation) without obtaining shareholder approval for that amendment.

Shareholder views

The Committee will consider shareholder feedback received following the AGM, as well as any additional feedback and
guidance received from time to time when considering any significant changes to the Company’s remuneration

SILENCE THERAPEUTICS PLC

arrangements. This feedback will be considered by the Committee as it develops the Company’s remuneration
framework and practices going forward. Assisted by its independent adviser, the Committee also actively monitors
developments in the expectations of institutional investors and their representative bodies.

Employment conditions

The Committee is regularly updated throughout the year on pay and conditions applying to Company employees. Where
significant changes are proposed to employment conditions and salary levels elsewhere in the Company these are
highlighted for the attention of the Committee at an early stage and the Committee will take such employment
considerations into account when setting directors’ remuneration.

Whilst the Committee does not currently consult directly with employees regarding its policy for directors, the Committee
is considering the best method of bringing the employee voice to the boardroom.

Other Remuneration Policies

Executive Directors’ Service Contracts

Executive Directors have rolling service agreements (entered into with the Company or a subsidiary thereof) which may
be terminated in accordance with the terms of these agreements. The period of notice for Executive Directors (to be
given by the employer or the Executive Director) will not normally exceed 12 months’ notice. Executive Directors’ service
agreements are available for inspection at the Company’s registered office during normal business hours and will also
be available to the public if required to be filed by the Parent Company with the SEC. The terms of the current Executive
Director’s service contract are:

Name
Position

Date of amended and
restated employment
agreement

Notice period for the
Executive
Craig Tooman

Chief Executive Officer

5 March 2022

No notice period for the
Company
45 days’ for the Executive
Director

The Executive Director may accept outside appointments, with prior Board approval, provided that these opportunities
do not negatively impact on their ability to fulfil their duties to the Company. Whether any related fees are retained by
the individual or are remitted to the Company will be considered on a case-by-case basis.

Executive Director Termination and Loss of Office Payments

The Company’s policy on remuneration for Executive Directors who leave the Company is set out below. The Committee
will exercise its discretion when determining amounts that should be paid to leavers (other than in respect of the relevant
leaver’s contractual entitlements which will be respected), taking into account the facts and circumstances of each case.
If and where applicable, the Company may elect to make a payment in lieu of notice (“PILON”) equivalent in value to
basic salary and contractual benefits for any unexpired portion of the notice period (but excluding any annual bonus or
holiday entitlement that would have otherwise accrued during the notice period).
Where the Executive Director is terminated by the Company without “Cause” (as defined in the service agreement) or
by the Executive Director for “Good Reason” (as defined in the service agreement), provided the Executive Director is
not in breach of the restrictive covenants (including post-termination) applicable to them, severance pay and any

SILENCE THERAPEUTICS PLC

entitlements in respect of the year to the date of termination in accordance with the applicable terms shall be paid to an
Executive Director as set out below, subject to the Executive Director signing a release and waiver of claims:

Element of pay / benefit

Termination other than within
12 months after a relevant
“Change of Control” (as defined in
the service agreement)

Termination within 12 months after
a relevant “Change of Control” (as
defined in the service agreement)
Salary
Monthly payments equal to base
salary in accordance with normal
payroll practices, less any applicable
taxes and withholdings for a period of
12 months
Monthly payments equal to base
salary in accordance with normal
payroll practices, less any applicable
taxes and withholdings for a period of
18 months
Bonus
Any unpaid short-term bonus for any
completed performance period and a
pro rata bonus for the year in which
the termination occurs based on the
achievement of applicable
performance goals
Any unpaid short-term bonus for any
completed performance period and a
pro rata bonus for the year in which
the termination occurs based on the
achievement of applicable
performance goals
Benefits

Provided continuation coverage is
elected, payment of the amount of
COBRA premiums that exceeds the
monthly amount that would have
been paid prior to termination, less
any applicable taxes and withholdings
until the earliest of (i) 12 months post
termination; (ii) the date the executive
first becomes eligible for healthcare
benefits with a subsequent employer;
and (iii) the date the executive is no
longer eligible for COBRA benefits

Provided continuation coverage is
elected, payment of the amount of
COBRA premiums that exceeds the
monthly amount that would have
been paid prior to termination, less
any applicable taxes and
withholdings until the earliest of (i) 18
months post termination; (ii) the date
the executive first becomes eligible
for healthcare benefits with a
subsequent employer; and (iii) the
date the executive is no longer
eligible for COBRA benefits
Equity awards
Awards treated in accordance with
plan rules.
Awards vest in full on a Change of
Control.

Where the Executive Director’s employment is terminated due to their incapacity or death, the Executive Director or
their estate will be entitled to any unpaid short-term bonus for any completed performance period in such amount as
may be earned and payable, if any, and a pro rata bonus for the year in which their termination occurs based on
achievement of applicable performance goals. With respect to all vested equity awards, the Executive Director’s
termination will be deemed a “Good Leaver Reason” or they will be deemed a “Good Leaver”, under the equity plan
rules, as applicable.

The Company is against rewards for failure; the circumstances of any departure, including the individual’s performance,
would be taken into account in every case. Statutory redundancy payments may be made. Service agreements may be
terminated for cause and in certain circumstances, such as gross misconduct or any other material breach of the
obligations under their employment contract without payment in lieu of notice if applicable or severance benefits. The
Company may require the individual to work during their notice period (if applicable) or may place them on garden leave
during which they would be entitled to full pay and benefits.

SILENCE THERAPEUTICS PLC

Except in the case of dismissal for cause or gross misconduct or resignation, the Company may at its absolute discretion
reimburse for reasonable professional fees relating to the termination of employment and, where an Executive Director
has been required to re-locate, to pay reasonable repatriation costs, including possible tax exposure costs and/or settle
any other amount the Committee considers reasonable including any statutory entitlements or sums to settle or
compromise claims or potential claims in connection with a termination (including, at the discretion of the Committee,
reimbursement for legal advice and provision of outplacement services). If post-termination services are to be provided
by the Executive Director, the Company may also enter into a consultancy agreement with such Executive Director on
such terms as may be agreed between the Company and the Executive Director at the time.

Non-Executive Directors’ Terms of Engagement

All Non-Executive Directors have specific terms of engagement which may be terminated on not less than three months’
notice by either party. The Chairman’s terms of engagement may be terminated on not less than six months’ notice by
either party.

The remuneration of Non-Executive Directors is determined by the Board within the limits set by the Articles and based
on a review of fees paid to Non-Executive Directors of similar companies.

A Board evaluation has been performed and the results of this exercise confirmed that all Non-Executive Directors were
independent. The dates of appointment of each of the Non-Executive Directors serving at 31 December 2024 are
summarised in the table below.

Non-Executive Directors
Date of appointment
Date of appointment letter
Michael Davidson

6 January 2021
5 January 2021
James Ede-Golightly

25 April 2019
3 August 2020
Dave Lemus

21 June 2018
3 August 2020
Iain Ross

25 April 2019
21 September 2020

Non-Executive Directors’ terms of engagement are available for inspection at the Company’s registered office during
normal business hours and will be available for inspection at the AGM.

On termination of a Non-Executive Director’s appointment, the Company may enter into a consultancy agreement with
such Non-Executive Director on such terms as may be agreed between the Company and the Non-Executive Director
at the time.

Remuneration for New Appointments

Where it is necessary to recruit or replace an Executive Director, the Committee has determined that the new Executive
Director will receive a compensation package in accordance with the provisions of the policy.

In setting base salaries for new Executive Directors, the Committee will consider the existing salary package of the new
Director and the individual’s level of experience.

SILENCE THERAPEUTICS PLC

In setting the annual performance bonus, the Committee may wish to set different performance metrics (to those of
other Executive Directors) in the first year of appointment. Where it is appropriate to offer a below-median salary on
initial appointment, the Committee will have the discretion to allow phased salary increases over a period of time for a
newly appointed Director, even though this may involve increases in excess of inflation and the increases awarded to
the wider workforce.

The Committee may make buy out awards to a new Executive Director to facilitate the recruitment process. The amount
of any such award would not exceed the expected value being forfeited and, to the extent possible, would mirror the
form of payment, timing and degree of conditionality. Where awards are granted subject to performance conditions,
these would be relevant to Silence Therapeutics plc. Any such award would only be made in exceptional circumstances
and shareholders would be informed of any such payments at the time of appointment. Share-based awards would be
made under the EIP or any successor plan.

In respect of internal appointments, any commitments entered in respect of a prior role, including variable pay elements,
may be allowed to pay out according to their prior terms.

For external and internal appointments, the Committee may consider it appropriate to pay reasonable relocation or
incidental expenses, including reasonable legal expenses. Tax equalisation may be considered if a Director is adversely
affected by taxation due to their employment or engagement with the Company.

The terms of appointment for a Non-Executive Director would be in accordance with the remuneration policy for Non-
Executive Directors as set out in the policy table.

Remuneration scenario for Executive Director

The charts below show an estimate of the 2025 remuneration package for the Executive Director under three assumed
performance scenarios and these scenarios are based on the policy set out above which will be applicable if it is
approved. No performance obligations apply to equity-based awards so they are not included.

Minimum (comprising fixed pay only)
Base salary as of 1 January 2025 of $655 thousand.

Target
Fixed pay as above.
Assumes target bonus of 60% of base salary.

Maximum
Fixed pay as above.
Assumes maximum bonus payout of 100% of base salary.

SILENCE THERAPEUTICS PLC
45
Remuneration Committee (the Committee)
Governance
In its decision-making process, the Committee takes account of information from both internal and independent sources
and AON Solutions UK Ltd surveys. AON Solutions UK Ltd were appointed as remuneration consultants by the
Committee based on their experience in the industry and relevant geographies via a tender process. AON Solutions UK
Ltd advises the Committee on all aspects of senior executive remuneration and has kept the Committee up to date on
remuneration trends and corporate governance best practice. AON Solutions UK Ltd does not have any other connection
with the Company and is considered to be independent by the Committee. During the year ended 31 December 2024,
fees charged by AON Solutions UK Ltd amounted to approximately £43 thousand (2023: £4 thousand).
The current members of the Committee are Michael Davidson, James Ede-Golightly, and Dave Lemus. Michael
Davidson, James Ede-Golightly and Dave Lemus are deemed to be independent.
The Company’s Chief Executive Officer and Chief Financial Officer provide updates to the Committee, as required, to
ensure that the Committee is fully informed about pay and performance issues throughout the Company. The Committee
takes these factors into account when determining the remuneration of the Executive Directors and senior executives.
No Executive Director or employee can participate in any discussion directly relating to their own personal conditions of
service or remuneration.
No conflicts of interest have arisen during the year and none of the members of the Committee has any personal financial
interest in the matters discussed, other than as option holders. The fees of the Non-Executive Directors are approved
by the Board on the joint recommendation of the Committee and the Chief Executive Officer.
The Committee met 4 times in 2024.

SILENCE THERAPEUTICS PLC

Director
Meetings attended
James Ede-Golightly

4/4
Michael Davidson

4/4
Dave Lemus

4/4

Role

The Committee’s principal function is to support the Company’s strategy by ensuring that those individuals responsible
for delivering the strategy are appropriately incentivised through the operation of the Company’s remuneration policy.
In determining the Company’s current policy, and in constructing the remuneration arrangements for Executive Directors
and senior employees, the Board, advised by the Committee, aims to provide remuneration packages that are
competitive and designed to attract, retain and motivate Executive Directors and senior employees of the highest calibre,
and align incentives with shareholder interest.

The Committee is responsible for:

setting a remuneration policy that is designed to promote the long-term success of the Company, including pension
rights and any compensation payments, and review the on-going appropriateness and relevance of the
remuneration policy;

ensuring that the remuneration of the Executive Director and other senior executives reflects both their individual
performance and their contribution to the overall Company results;

determining the terms of employment and remuneration of the Executive Director and senior executives, including
recruitment and retention terms, whilst having regard to pay and employment conditions across the Company or
group;

ensuring that contractual terms on termination, and any payments made, are fair to the individual, and the Company,
that failure is not rewarded and that the duty to mitigate loss is fully recognized;

approving the design and performance targets of any annual incentive arrangements that include the Executive
Director and senior executives;

approving the design and performance targets, where applicable, of all share incentive plans requiring shareholder
approval;

rigorously assessing the appropriateness and subsequent achievement of the performance targets related to any
incentive arrangements;

determining each year whether awards will be made under the incentive arrangements, and if so, the overall amount
of such awards;

recommending to the Board the fees to be paid to the Chair. The Chair is excluded from this process;

gathering and analysing appropriate data from comparator companies in the biotech sector;

the selection and appointment of the external advisers to the Committee to provide independent remuneration
advice where necessary;

Approval to amend Remuneration Committee Charter to comply with Nasdaq requirements;

Each member of the committee will satisfy: (a) the independence and other requirements imposed by applicable
law and the listing requirements of The Nasdaq Stock Market LLC (“Nasdaq”); and (b) any other qualifications
determined by the board; and

The chairperson will have the delegated authority to act on behalf of the committee in connection with (a) the
negotiation and execution of engagement letters of compensation consultants, legal counsel or other advisors to be
retained by the committee and (b) as may otherwise be determined by the committee.

SILENCE THERAPEUTICS PLC

Pay-for-Performance Scenario Analysis

The charts below provide an estimate of the potential reward opportunities for the Executive Director, and the potential
split between different elements of remuneration under two performance scenarios: “Earned” and “Minimum”.
Craig Tooman

Amounts are shown in thousands (GBP).
The EIP award amounts shown represents the amount as shown in the directors’ remuneration table.

494
494
1
1
24
24
281
£000
-
100
200
300
400
500
600
700
800
900
Earned
Minimum - Fixed
Compensation
Salary
Benefits
Pension
Bonus
EIP

SILENCE THERAPEUTICS PLC

Annual Report on Remuneration
This section of the Remuneration report provides details of how our remuneration policy was implemented during the
financial year ended 31 December 2024, and how it will be implemented during the year ending 31 December 2025.

This report splits certain information into that for Executive Directors and that for Non-Executive Directors.

Audited Information

Directors’ Remuneration – financial year ended 31 December 2024

The total remuneration of the individual Directors who served during the period is shown below. Total remuneration is
the sum of emoluments for the period in service as a director plus Company pension contributions, and the value of
long-term incentive awards vesting by reference to performance in the twelve months to 31 December 2024.

Year
Basic
Salary(a)
Benefits (b)
Bonus
(c)
EIP (d)
Pension (e)
Total
remuneration
Total fixed
remuneration
Total Variable
remuneration

£000s
£000s
£000s
£000s
£000s
£000s
£000s
£000s
Executive Directors

Craig Tooman
2024
494
1
281
-
24
800
519
281

2023
473
1
425
-
24
923
498
425
Non-Executive
Directors

Iain Ross
2024
92
-
-
-
-
92
92
-

2023
94
-
50
-
-
144
94
50
Alistair Gray (f)
2024
18
-
-
-
-
18
18
-

2023
56
-
-
-
-
56
56
-
Dave Lemus
2024
46
-
-
-
-
46
46
-

2023
47
-
-
-
-
47
47
-
James Ede-GoLightly
2024
44
-
-
-
-
44
44
-

2023
45
-
-
-
-
45
45
-
Michael Davidson
2024
40
-
-
-
-
40
40
-

2023
41
-
-
-
-
41
41
-

Notes to the Remuneration Table
(a)
This is the amount earned in respect of the financial year.
(b)
This is the taxable value of benefits paid or payable in respect of the financial year.
(c)
For 2024, this is the total bonus earned under the annual bonus scheme in respect of the financial year
(despite being paid in the following financial year, following determination of final outcomes).
(d)
There were no performance obligations linked to the equity-based awards. The value of equity-based awards
in the form of options in the table is based on the market value of underlying shares at the date of grant, less the
applicable exercise price. This was nil because the exercise price is equal to the market value of the underlying
shares at the date of grant. Refer to “Scheme interests awarded in 2024” below. Share price appreciation did not
impact the value of awards. No discretion was exercised, and the determination of the levels of awards were not
impacted, as a result of share price appreciation.

SILENCE THERAPEUTICS PLC

(e)
The amount shown relates to company contributions to the defined contribution scheme, plus any cash in lieu.
(f)
Mr. Gray served as a director until he resigned on 30 April 2024.

Annual Performance Bonus - 2024

In 2024, all employees were eligible for an annual discretionary cash bonus, whereby performance objectives are
established at the beginning of the financial year by reference to suitably challenging corporate goals. Non-Executive
Directors are not eligible for annual performance bonuses.

The Executive Director’s maximum bonus opportunity was 60% of salary (£296,000), with performance tested wholly
against corporate goals. For all other employees the maximum bonus opportunities ranged from 8% to 40% of salary,
depending on grade and the percentage attributable to individual goals for employees range from 30% to 150%
depending on level.

Bonus payments are not pensionable.

The achievement against the scorecard of corporate goals was as follows:

Target

Weighting
2024
achievement

%
%
SLN360: milestone delivery

Achieve planned targets for the development of SLN
360

20.0

19.5

SLN124: milestone delivery
Achieve planned targets for the development of SLN
124

20.0

21.0

Manufacturing processes
Achieve planned manufacturing for all programmes

15.0

New business development deals

Secure high value business development deal

10.0

5.0

Candidate selection
Achieve planned activity and identification of new
targets

10.0

9.5

Compliance and Quality:
Maintain regulatory compliance and quality systems
7.5

7.5

Achievement of financial targets

Maintain a cash runway and reporting on KPIs

17.5

Total

100.0

95.0

SILENCE THERAPEUTICS PLC

Achievement against objectives is given careful consideration by the Committee prior to finalisation. Each objective is
reviewed for overall achievement. For some objectives, further entitlement was approved as the goals were
overachieved. The Committee acknowledged the team's significant progress in advancing our clinical-stage
programmes in 2024, further financing key programmes, and expanding the US investor base. Therefore, the board
determined an achievement score of 95% was fair and justifiable.

The Committee reviewed the formulaic outcome of the scorecard and concluded that the scorecard outcome, as shown
above, reflected the performance of the Executive Directors in the year. The resulting annual bonus award was at 57%
of salary (£281,000):

Scheme Interests

During the year ended 31 December 2024 Craig Tooman was awarded share option awards under the EIP scheme,
details of which are summarised in the table below. EIP awards were granted under the Silence Therapeutics plc 2024
Employee Incentive Plan and were based on an industry peer analysis.

Directors share awards

Individual
Date of
Grant
At 1 Jan
2024
Awarded
Exercised
Cancelled
At 31
Dec 2024
Exercise
price
($/share)
Gain on
exercise
s during
the year
(£000s)
Earliest
date of
exercise
Last
date of
exercise

Iain Ross
10/06/2019
250,000
-
-
-
250,000
$2.53
-
01/06/20
10/06/29

10/06/2019
250,000
-
-
-
250,000
$0.80
-
01/06/20
10/06/29

21/05/2020
150,000
-
-
-
150,000
$0.07
-
25/04/22
20/05/30

21/05/2020
350,000
-
-
-
350,000
$5.87
-
21/08/20
20/05/30

06/01/2022
90,000
-
-
-
90,000
$7.87
-
06/02/22
06/01/32

14/09/2023
90,000
-
-
-
90,000
$5.13
-
15/09/23
12/09/33

04/01/2024
-
90,000
-
-
90,000
$5.90
-
05/01/24
04/01/34

Alistair Gray
6/01/2022
48,000
-
-
-
48,000
$7.87
-
06/02/22
06/01/32

14/09/2023
48,000
-
-
-
48,000
$5.13
-
15/09/23
12/09/33

04/01/2024
-
48,000
-
-
48,000
$5.90
-
05/01/24
04/01/34

Dave Lemus
6/01/2022
48,000
-
-
-
48,000
$7.87
-
06/02/22
06/01/32

14/09/2023
48,000
-
-
-
48,000
$5.13
-
15/09/23
12/09/33

14/09/2023
20,001
-
-
-
20,001
$5.13
-
15/09/23
12/09/33

04/01/2024
-
48,000
-
-
48,000
$5.90
-
05/01/24
04/01/34

James Ede-
GoLightly
06/01/2022
48,000
-
-
-
48,000
$7.87
-
06/02/22
06/01/32

14/09/2023
48,000
-
-
-
48,000
$5.13
-
15/09/23
12/09/33

04/01/2024
-
48,000
-
-
48,000
$5.90
-
05/01/24
04/01/34

SILENCE THERAPEUTICS PLC

Individual
Date of
Grant
At 1 Jan
2024
Awarded
Exercised
Cancelled
At 31
Dec 2024
Exercise
price
($/share)
Gain on
exercise
s during
the year
(£000s)
Earliest
date of
exercise
Last
date of
exercise

Michael
Davidson
06/01/2022
48,000
-
-
-
48,000
$7.87
-
06/02/22
06/01/32

14/09/2023
48.000
-
-
-
48,000
$5.13
-
15/09/23
12/09/33

04/01/2024
-
48,000
-
-
48,000
$5.90
-
05/01/24
04/01/34

Craig
Tooman
06/01/2021
579,999
-
-
-
579,999
$7.02
-
06/01/22
06/01/31

06/01/2022
264,999
-
-
-
264,999
$7.87
-
06/02/22
06/02/32

21/02/2022
375,000
-
-
-
375,000
$6.33
-
21/03/22
21/03/32

16/09/2022
900,000
-
-
-
900,000
$3.86
-
16/10/22
16/10/32

05/01/2023
2,100,000
-
-
-
2,100,000
$5.13
-
06/01/23
03/01/33

14/09/2023
216,960
-
-
-
216,960
$3.33
-
15/09/23
03/01/33

04/01/2024
-
650,880
-
-
650,880
$5.90
-
04/01/25
04/01/34

Scheme interests awarded in 2024

Name

Date of grant

Number of
Shares
awarded (1)

Exercise
Price

Face Value
(2) £000s

Vesting
Schedule
Craig Tooman
04/01/2024
650,880
$5.90
3,065

Note 3
Iain Ross
04/01/2024
90,000
$5.90
424

Note 4
Alistair Gray
04/01/2024
48,000
$5.90
226

Note 4
Dave Lemus
04/01/2024
48,000
$5.90
226

Note 4
James Ede-GoLightly
04/01/2024
48,000
$5.90
226

Note 4
Michael Davidson

04/01/2024

48,000

$5.90

226

Note 4
1. The awards to the CEO were based on a third-party analysis of CEO grant values in the Companies peer market group. The awards to the Executive Directors were
based on a fixed number of shares for each position.
2. Face value is calculated as the market value of underlying shares at the date of grant, or exercise price for the number of shares awarded.
3. Share options vest 25% at first anniversary of grant then equal monthly vesting tranches for 36 months. These awards are not subject to any performance conditions.
4. Share options vest in 36 equal monthly vesting tranches starting from the month of grant. These awards are not subject to any performance conditions.

Directors' interests in shares at 31 December 2024

Director
Total shares
owned outright
plus vested
options
Shares Owned
outright
Percentage of
issued share
capital
Options:
Vested but not
exercised
Options:
Unvested but
subject to
performance
Options:
Unvested and not
subjected to
performance

SILENCE THERAPEUTICS PLC
52
Current directors

Craig Tooman
2,515,137
33,486
1.8%
2,481,651
-
2,606,187
Iain Ross
1,192,437
39,942
0.9%
1,152,495
-
117,498
Dave Lemus
88,863
7,527
0.06%
81,336
-
62,664
James Ede-Golightly
96,336
15,000
0.07%
81,336
-
62,664
Dr. Michael Davidson
94,329
12,993
0.07%
81,336
-
62,664
No options were exercised in the year.
Directors are encouraged to build a meaningful shareholding so as to align their interests with those of shareholders but no formal shareholding requirements applied
during 2024.
Unaudited Information
Performance Graph and Table
The following graph shows Silence’s cumulative Total Shareholder Return (TSR) over the last five financial years relative
to the Nasdaq Biotech Index.
TSR is defined as the return on investment obtained from holding a company’s shares over a period. It includes
dividends paid, the change in capital value of the shares and any other payment made to or by shareholders within the
period
Aligning Pay with Performance
CEO remuneration compared with annual growth in TSR:
The total remuneration figure for the CEO (Craig Tooman) is shown in the table below, along with the value of bonuses
paid in respect of the year, and fair value of options granted, as a percentage of the total remuneration.

SILENCE THERAPEUTICS PLC

Craig Tooman

2024

£000s

Total remuneration

800

Actual bonus as a % of the remuneration

35%
Actual share award as % of the remuneration

Craig Tooman
2023

£000s
Total remuneration

923
Actual bonus as a % of the remuneration

46%
Actual share award as % of the remuneration

Craig Tooman
2022

£000s
Total remuneration

643
Actual bonus as a % of the remuneration

35%
Actual share award as % of the remuneration

0%
*As 2021 was the first year reported since listing on NASDAQ and therefore the first year for which this disclosure is required, it is not possible to provide meaningful
comparative data.

Percentage Change in Remuneration of the Directors and Employees

Set out below is the change over the prior period in base salary, benefits, pension and annual performance bonus for
the Directors and the Company’s employees. Only Directors in office during any part of the 2024 year have been
included below.

Salary % Change
Benefits % Change
Bonus % Change

2023 vs 2024
2023 vs 2024
2023 vs 2024
Craig Tooman (Note 3)
4%
1%
(34)%
Iain Ross
(3)%
Note 1
Note 1
Dave Lemus
(3)%
Note 1
Note 1
James Ede-Golightly
(3)%
Note 1
Note 1
Dr. Michael Davidson
(3)%
Note 1
Note 1
All employees excl. directors
5%

(5)%

SILENCE THERAPEUTICS PLC

Salary % Change
Benefits % Change
Bonus % Change

2022 vs 2023
2022 vs 2023
2022 vs 2023
Craig Tooman (Note 3)
16%

94%

92%
Iain Ross
4%

Note 1

Note 2
Dave Lemus
4%

Note 1

Note 1
James Ede-Golightly
2%

Note 1

Note 1
Dr. Michael Davidson
2%

Note 1

Note 1
All employees excl. directors
3%

10%

Salary % Change
Benefits % Change
Bonus % Change

2021 vs 2022
2021 vs 2022
2021 vs 2022
Iain Ross

(25)%

Note 1

Note 2
Dave Lemus

(16)%

Note 1

Note 1
James Ede-Golightly

(20)%

Note 1

Note 1
Dr. Michael Davidson

(33)%

Note 1

Note 1
All employees excl. directors
3%

Salary % Change
Benefits % Change
Bonus % Change

2020 vs 2021
2020 vs 2021
2020 vs 2021
Iain Ross

Note 1

Note 2
Dave Lemus

22%

Note 1

Note 1
James Ede-Golightly

22%

Note 1
Note 1
Michael Davidson

N/A

N/A
All employees excl. directors

Salary % Change
Benefits % Change
Bonus % Change

2019 vs 2020
2019 vs 2020
2019 vs 2020
Iain Ross

Note 1
Note 1
Note 1
Dave Lemus

13%
Note 1
Note 1
James Ede-Golightly

13%
Note 1
Note 1
Michael Davidson

N/A
N/A
N/A
All employees excl. directors

4%
3%
4%

1. Non-executive directors were not entitled to a bonus in any year, which the exception of Iain Ross. They were not entitled to benefits in any year, with the exception of
Alistair Gray and Dave Lemus who were paid benefits of £13 thousand and £2 thousand, respectively in 2019.
2. Iain Ross was appointed as Executive Chairman on 17 December 2019. Base salary included additional remuneration of £9 thousand (exclusive of VAT) relating to
duties undertaken in December 2019 as Executive Chairman. This amount was billed by Iain Ross’ consultancy company (Gladstone Consulting Partnership) in January

SILENCE THERAPEUTICS PLC

2020. Iain Ross was paid £15 thousand (exclusive of VAT) on a monthly basis until one month following the appointment of a new CEO. In 2020, in recognition of the
additional Executive responsibilities and in addition to his monthly Chairman/Director fees of £10 thousand per month Mr Ross was paid an additional remuneration of
£15k per month invoiced through his consultancy firm Gladstone Consultancy Partnership for the period 1 January to - 31 May 2020. In the absence of a permanent CEO
appointment, on 1 June Mr Ross signed an employment contract immediately terminable 1 month following the appointment of a new CEO. For the period 1 June - 14
October 2020 Mr Ross was paid £30 thousand per month plus benefits including a contribution to pension and private healthcare insurance of £3 thousand. On 14
September 2020 Mr Ross reverted to his role as Non-executive Chairman and from 1 month after this date reverted to his monthly fees of £10 thousand per month. On
signing the employment agreement effective 1 June 2020 Mr Ross was paid a one-off bonus of £75 thousand in respect of services rendered 17 December 2019 - 31 May
2020. Upon completion of his time as Interim Executive Chairman Mr Ross was paid a further one-off bonus of £80 thousand in respect of services rendered during the
remainder of his time in this Executive role. Throughout 2021, Iain maintained a salary of £10 thousand per month. He was not paid a bonus or benefits in either 2021 or
2022. In 2023, he was paid a bonus of £50 thousand.
3. Craig Tooman was appointed was appointed as a Director (Chief Executive Officer) on 21 February 2022 and therefore prior year data is not available.

Relative Importance of Spend on Pay

Total revenue and research and development expenditure have been selected as comparators for the employee costs
as these two financial measures are strong indicators of the activity within the Company and of its performance.

2023
2024
Change

£000/number
£000/number
%
Total employee remuneration

30,426
29,838
(2)%
Average number of employees

115
116
Nil
Revenue

25,375
33,833
33%
Research and development expenditure

44,025
53,304
21%

No dividends distributions or share buyback transactions occurred in either 2023 or 2024.

Statement of Implementation of Policy in 2025

Base Salary: The January 2025 target base salary increase was an average of 5% for all eligible employees. There
was a 5% increase in Craig Tooman’s base salary to $655,000.

Pension and Benefits: In 2025, Craig Tooman is eligible for the same benefits as provided to all senior employees
being health insurance, long-term disability, life insurance. Craig Tooman is also entitled to a 100% match of 401k
contributions up to 6% of his respective base salary or the maximum allowed by IRS rules.

Annual Performance Bonus: For 2025, the Craig Tooman’s annual cash bonus target pay-outs will be 60% of annual
base salary. The Committee considers overall corporate performance and individual performance when determining the
final bonus amount to be awarded to an Executive Director. Performance will be tested against targets set by the
Committee at the start of the year and will comprise 100% corporate goals for Craig Tooman. The Company’s 2025
corporate objectives are weighted as follows:

The following tables sets out the Company’s performance objectives for 2025.

SILENCE THERAPEUTICS PLC
56
Objective
Weighting
1
Deliver on partnering and management of capital
30%
2
Deliver on clinical milestones
30%
3
Sustain competitive platform
15%
4
Manufacturing, compliance and quality
15%
5
Corporate execution and resilient operations
10%
TOTAL
100%
Specific targets are commercially sensitive and therefore are not disclosed in advance. However, full details of the
targets and performance against them will be disclosed when they are no longer considered commercially sensitive.
Payments for Loss of Office and Payment to Former Directors (audited information)
There were no loss of office payments or payment to former directors in 2024.
Shareholder voting on remuneration matters at AGM
The table below sets out the votes cast at our AGM in May 2024 in respect of the previous Directors’ Remuneration
Report and the Directors’ Remuneration Policy:
Votes for
Votes against
Votes withheld
%
Number
%
Number
Number
Directors' Remuneration Report
88.2
52,627,531
11.8
7,034,877
1,156,296
Directors' Remuneration Policy
79.5
47,398,493
20.6
12,260,915
1,159,296
James Ede-Golightly
Chair of the Remuneration Committee

SILENCE THERAPEUTICS PLC

Directors’ Report
The Directors present their report and the audited financial statements of the Group for the year ended 31 December
2024.
Principal Activities
The Company has full control and ownership of the following subsidiaries:
•
Silence Therapeutics GmbH
•
Silence Therapeutics (London) Ltd
•
Innopeg Ltd
•
Silence Therapeutics Inc.
The Company, Silence Therapeutics GmbH, Silence Therapeutics (London) Ltd, Innopeg Ltd and Silence Therapeutics
Inc. are collectively referred to as the “Group”.
The principal activity of the Group is focused on the discovery, delivery and development of RNA therapeutics.
Statement of Directors’ Responsibilities

The directors are responsible for preparing the Annual Report and the financial statements in accordance with applicable
law and regulation.

Company law requires the directors to prepare financial statements for each financial year. Under that law the directors
have prepared the group financial statements in accordance with UK-adopted international accounting standards and
the company financial statements in accordance with United Kingdom Generally Accepted Accounting Practice (United
Kingdom Accounting Standards, comprising FRS 101 “Reduced Disclosure Framework”, and applicable law).

Under company law, directors must not approve the financial statements unless they are satisfied that they give a true
and fair view of the state of affairs of the group and company and of the profit or loss of the group for that period. In
preparing the financial statements, the directors are required to:

select suitable accounting policies and then apply them consistently;

state whether applicable UK-adopted international accounting standards have been followed for the group
financial statements and United Kingdom Accounting Standards, comprising FRS 101 have been followed for
the company financial statements, subject to any material departures disclosed and explained in the financial
statements;

make judgements and accounting estimates that are reasonable and prudent; and

prepare the financial statements on the going concern basis unless it is inappropriate to presume that the group
and company will continue in business.

The directors are responsible for safeguarding the assets of the group and company and hence for taking reasonable
steps for the prevention and detection of fraud and other irregularities.

The directors are also responsible for keeping adequate accounting records that are sufficient to show and explain the
group’s and company’s transactions and disclose with reasonable accuracy at any time the financial position of the

SILENCE THERAPEUTICS PLC

group and company and enable them to ensure that the financial statements and the Directors’ Remuneration Report
comply with the Companies Act 2006.

The directors are responsible for the maintenance and integrity of the company’s website. Legislation in the United
Kingdom governing the preparation and dissemination of financial statements may differ from legislation in other
jurisdictions.

Directors’ confirmations

In the case of each director in office at the date the directors’ report is approved:

so far as the director is aware, there is no relevant audit information of which the group’s and company’s auditors
are unaware; and

they have taken all the steps that they ought to have taken as a director in order to make themselves aware of
any relevant audit information and to establish that the group’s and company’s auditors are aware of that
information.

Review of the Business and Future Developments
The strategic report describes research and development activity during the year as well as outlining future planned
developments. Details of the financial performance, including comments on the cash position and research and
development expenditure, are given in the Strategic Report. Principal risks and uncertainties are given in the strategic
report.
Health, Safety and Environment
The Directors are committed to ensuring the highest standards of health and safety, both for their employees and for
the communities within which the Group operates and also minimising the impact of the Group’s operations on the
environment; see detailed statement in the Corporate Social Responsibility section of the Strategic Report. The Group’s
estimated electricity usage for the reporting period is 578,000 kWh (an estimated 120 metric tons of CO2 equivalent
emissions), with 12% of that estimated usage occurring in the United Kingdom. The Group’s premises are located in
shared facilities so energy consumption is estimated based on space leased.
Employees
The Directors are committed to continuing involvement and communication with employees on matters affecting both
employees and the Group. Management conducts regular meetings with all employees on site.
Branches outside of the United Kingdom
The Company has no overseas branches.

Political and charitable contributions
The Group did not make any political donations or incur any political expenditure during the year (2023: nil). The Group
made total charitable donations of £nil during the year (2023: nil).
Research and Development
In 2024, the Group spent £53.3 million on research and development (2023: £44.0 million).

SILENCE THERAPEUTICS PLC

Subsequent Events
The Group has no subsequent events.
Financial Risk Management
A description of financial risk management is set out in note 27 to the financial statements.
Results and Dividends
The Group recorded a loss for the year before taxation of £45.1 million (2023: £50.3 million). The loss after tax for the
year was £35.2 million (2023: £43.3 million). Further details are given in the Strategic Report. The Group is not yet in a
position to pay a dividend and the loss for both periods has been added to accumulated losses.
Indemnification of Directors
Qualifying third party indemnity provisions (as defined in the Companies Act 2006) are in force for the benefit of Directors
and former Directors who held office during 2024 and up to the signing of the annual report.
Directors
The Directors who served at any time during the year or since the year end were:

Director

Job title
Iain Ross

Chairman
Craig Tooman

Chief Executive Officer
Alistair Gray (resigned as Director: 1 May 2024)

Non-Executive
Dave Lemus

Non-Executive
James Ede-Golightly

Non-Executive
Dr. Michael Davidson

Non-Executive

The interests of the Directors in the share options of the Company are set out in the Directors’ remuneration report.

This report was approved by the Board of Directors and signed on its behalf by:

Craig Tooman

Chief Executive Officer
29 April 2025

SILENCE THERAPEUTICS PLC

Financial statements

Independent auditors’ report to the members of Silence Therapeutics plc
Consolidated income statement

Consolidated statement of comprehensive income

Consolidated balance sheet

Consolidated statement of changes in equity
Consolidated statement of cash flow
Notes to the consolidated financial statements
Company balance sheet
Company statement of changes in equity

Notes to the financial statements

Company information and advisers

SILENCE THERAPEUTICS PLC

Independent auditors’ report to the members
of Silence Therapeutics Plc
Report on the audit of the financial statements
Opinion
In our opinion:
Silence Therapeutics Plc’s group financial statements and parent company financial statements (the “financial
statements”) give a true and fair view of the state of the group’s and of the parent company’s affairs as at
31 December 2024 and of the group’s loss and the group’s cash flows for the year then ended;
the group financial statements have been properly prepared in accordance with UK-adopted international accounting
standards as applied in accordance with the provisions of the Companies Act 2006;
the parent company financial statements have been properly prepared in accordance with United Kingdom Generally
Accepted Accounting Practice (United Kingdom Accounting Standards, including FRS 101 “Reduced Disclosure
Framework”, and applicable law); and
the financial statements have been prepared in accordance with the requirements of the Companies Act 2006.
We have audited the financial statements, included within the Annual Report, which comprise: the Consolidated and Company balance
sheets as at 31 December 2024; the Consolidated income statement, the Consolidated statement of comprehensive income, the
Consolidated statement of cash flows and the Consolidated and Company statements of changes in equity for the year then ended; and the
notes to the financial statements, comprising material accounting policy information and other explanatory information.
Basis for opinion
We conducted our audit in accordance with International Standards on Auditing (UK) (“ISAs (UK)”) and applicable law. Our responsibilities
under ISAs (UK) are further described in the Auditors’ responsibilities for the audit of the financial statements section of our report. We believe
that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our opinion.
Independence
We remained independent of the group in accordance with the ethical requirements that are relevant to our audit of the financial statements
in the UK, which includes the FRC’s Ethical Standard, as applicable to listed entities, and we have fulfilled our other ethical responsibilities
in accordance with these requirements.
Our audit approach
Context
Silence Therapeutics Plc is a public limited company incorporated under the laws of England and Wales and is listed on NASDAQ.
Overview
Audit scope
We performed full scope audits over 2 of the 5 reporting units, as these were considered significant due to their size.
We also performed audit procedures over the group consolidation adjustments and financial statement disclosures.
The reporting units over which we performed full scope audits, along with the consolidation adjustments, accounted
for 100% of the loss before tax and 100% of revenue. Our audit scope provided sufficient appropriate audit evidence
as a basis for our opinion on the Group financial statements as a whole.
Key audit matters

SILENCE THERAPEUTICS PLC

Accuracy of management’s assessment of third party research and development (“R&D”) accruals and prepayments
(group and parent)
Materiality
Overall group materiality: £2,254,000 (2023: £2,515,000) based on 5% of Loss before tax.
Overall parent company materiality: £2,487,000 (2023: £2,263,000) based on 5% of Loss before tax.
Performance materiality: £1,690,000 (2023: £1,886,000) (group) and £1,865,000 (2023: £1,697,000) (parent
company).
The scope of our audit
As part of designing our audit, we determined materiality and assessed the risks of material misstatement in the financial statements.
Key audit matters
Key audit matters are those matters that, in the auditors’ professional judgement, were of most significance in the audit of the financial
statements of the current period and include the most significant assessed risks of material misstatement (whether or not due to fraud)
identified by the auditors, including those which had the greatest effect on: the overall audit strategy; the allocation of resources in the
audit; and directing the efforts of the engagement team. These matters, and any comments we make on the results of our procedures
thereon, were addressed in the context of our audit of the financial statements as a whole, and in forming our opinion thereon, and we do
not provide a separate opinion on these matters.
This is not a complete list of all risks identified by our audit.
Accuracy of management's percentage of completion assessment of revenue recognition under collaboration agreements (group and
parent) and carrying value of the investment in Silence Therapeutics GmbH (parent only), which were key audit matters last year, are no
longer included because of the reduced levels of estimation uncertainty in these financial statement line items. Otherwise, the key audit
matters below are consistent with last year.
Key audit matter
How our audit addressed the key audit matter
Accuracy of management’s assessment of third party research and
development (“R&D”) accruals and prepayments (group and parent)

Management recognise expenditure with third parties in carrying out its R&D
activities based on their best estimation of the costs incurred for each
separately contracted study or activity. This includes the calculation of R&D
accruals and prepayments at each period end to account for expenditure that
has been incurred. This requires estimation of the current stage of
completion of each project versus the amounts billed. Our audit risk focuses
on whether the associated accruals and prepayments have been correctly
recorded. As at 31 December 2024, third party R&D contracts totalled £8.7m
in prepayments and £4.7m in accruals. Please see notes 16 and 18 for
further details.
We have obtained management’s calculations of third
party R&D accruals and prepayments, and tested the
mathematical accuracy of the model.

We tested the completeness and accuracy of the
underlying data used within the model, including total
contract costs and actual billed amounts, on a sample
basis. We also read all new significant R&D contracts
and checked that they were appropriately included in
Management’s model.

We tested a sample of R&D accruals and prepayments,
performing the following procedures:
- Obtained the underlying contracts and understood the
basis on which the project managers assessed the
estimated stage of completion at year end; and,
- Verified the estimated stage of completion by reviewing
the support available from third parties.

We also tested the effectiveness of management's
controls relating to the accuracy of the R&D accruals and
prepayments whereby they perform an annual
confirmation of the stage of completion of a contract with
the third party.

SILENCE THERAPEUTICS PLC
63
How we tailored the audit scope
We tailored the scope of our audit to ensure that we performed enough work to be able to give an opinion on the financial statements as a
whole, taking into account the structure of the group and the parent company, the accounting processes and controls, and the industry in
which they operate.
We tailored the scope of our audit to ensure that we performed enough work to be able to give an opinion on the financial statements as a
whole, taking into account the structure of the group and the company, the accounting processes and controls, and the industry in which they
operate.
The Group has 5 reporting units with a centralised finance function and integrated consolidation system. We assessed whether each reporting
unit was significant due to risk or size, non-significant or inconsequential and we determined that Silence Therapeutics plc (incorporated in
the UK) and Silence Therapeutics GmbH (incorporated in Germany) were significant due to size. We determined that all of the work that
needed to be performed over the reporting units could be performed by the Group team.
In addition to the work performed over the significant reporting units, the Group team audited the consolidation adjustments and Group
financial statement disclosures prepared by the head office finance team.
Reporting units where audit procedures were performed accounted for 100% of the Group revenue and 100% of the Group loss before tax.
The Group also has 3 reporting units that we assessed to be inconsequential both individually and in aggregate.
The Company's accounting records and controls and the Company financial statement disclosures prepared by the head office finance team.
The impact of climate risk on our audit
As part of our audit we made enquiries of management to understand the extent of the potential impact of climate risk on the group’s and
company’s financial statements, and we remained alert when performing our audit procedures for any indicators of the impact of climate
risk. Our procedures did not identify any material impact as a result of climate risk on the group’s and company’s financial statements.
Materiality
The scope of our audit was influenced by our application of materiality. We set certain quantitative thresholds for materiality. These, together
with qualitative considerations, helped us to determine the scope of our audit and the nature, timing and extent of our audit procedures on
the individual financial statement line items and disclosures and in evaluating the effect of misstatements, both individually and in aggregate
on the financial statements as a whole.
Based on our professional judgement, we determined materiality for the financial statements as a whole as follows:
Financial statements - group
Financial statements - parent company
Overall
materiality
£2,254,000 (2023: £2,515,000).
£2,487,000 (2023: £2,263,000).
How we
determined it
5% of Loss before tax
5% of Loss before tax
Rationale for
benchmark
applied
The Group is loss making, as expected given its
status as an early stage biotech company which
has not yet commercialised its products. As such,
loss before tax is deemed to be the most
appropriate benchmark on which to calculate
materiality, as this is the metric on which the
Group's financial performance is assessed.
The company is loss making, as expected given
its status as an early stage biotech company
which has not yet commercialised its products. As
such, loss before tax is deemed to be the most
appropriate benchmark on which to calculate
materiality, as this is the metric on which the
company's financial performance is assessed.
For each component in the scope of our group audit, we allocated a materiality that is less than our overall group materiality. The range of
materiality allocated across components was between £1,475,100 and £1,854,900. Certain components were audited to a local statutory
audit materiality that was also less than our overall group materiality.
We use performance materiality to reduce to an appropriately low level the probability that the aggregate of uncorrected and undetected
misstatements exceeds overall materiality. Specifically, we use performance materiality in determining the scope of our audit and the nature

SILENCE THERAPEUTICS PLC
64
and extent of our testing of account balances, classes of transactions and disclosures, for example in determining sample sizes. Our
performance materiality was 75% (2023: 75%) of overall materiality, amounting to £1,690,000 (2023: £1,886,000) for the group financial
statements and £1,865,000 (2023: £1,697,000) for the parent company financial statements.
In determining the performance materiality, we considered a number of factors - the history of misstatements, risk assessment and
aggregation risk and the effectiveness of controls - and concluded that an amount at the upper end of our normal range was appropriate.
We agreed with those charged with governance that we would report to them misstatements identified during our audit above £112,700
(group audit) (2023: £125,000) and £124,350 (parent company audit) (2023: £113,000) as well as misstatements below those amounts that,
in our view, warranted reporting for qualitative reasons.
Conclusions relating to going concern
Our evaluation of the directors’ assessment of the group's and the parent company’s ability to continue to adopt the going concern basis of
accounting included:
Testing the mathematical accuracy of the cash flow forecasts;
Challenging management's forecasts for reasonableness, including understanding the planned cash outflows /
inflows;
Assessing management's ability to forecast accurately by comparing the current year actual results to previous
cashflow forecasts;
Performing a sensitivity analysis on management's model to consider the potential impact of certain downside but
plausible scenarios; and
Evaluating the disclosures within the financial statements.
Based on the work we have performed, we have not identified any material uncertainties relating to events or conditions that, individually or
collectively, may cast significant doubt on the group's and the parent company’s ability to continue as a going concern for a period of at least
twelve months from when the financial statements are authorised for issue.
In auditing the financial statements, we have concluded that the directors’ use of the going concern basis of accounting in the preparation
of the financial statements is appropriate.
However, because not all future events or conditions can be predicted, this conclusion is not a guarantee as to the group's and the parent
company's ability to continue as a going concern.
Our responsibilities and the responsibilities of the directors with respect to going concern are described in the relevant sections of this report.
Reporting on other information
The other information comprises all of the information in the Annual Report other than the financial statements and our auditors’ report
thereon. The directors are responsible for the other information. Our opinion on the financial statements does not cover the other information
and, accordingly, we do not express an audit opinion or, except to the extent otherwise explicitly stated in this report, any form of assurance
thereon.
In connection with our audit of the financial statements, our responsibility is to read the other information and, in doing so, consider whether
the other information is materially inconsistent with the financial statements or our knowledge obtained in the audit, or otherwise appears to
be materially misstated. If we identify an apparent material inconsistency or material misstatement, we are required to perform procedures
to conclude whether there is a material misstatement of the financial statements or a material misstatement of the other information. If, based
on the work we have performed, we conclude that there is a material misstatement of this other information, we are required to report that
fact. We have nothing to report based on these responsibilities.
With respect to the Strategic report and Directors' Report, we also considered whether the disclosures required by the UK Companies Act
2006 have been included.
Based on our work undertaken in the course of the audit, the Companies Act 2006 requires us also to report certain opinions and matters as
described below.

SILENCE THERAPEUTICS PLC
65
Strategic report and Directors' Report
In our opinion, based on the work undertaken in the course of the audit, the information given in the Strategic report and Directors' Report
for the year ended 31 December 2024 is consistent with the financial statements and has been prepared in accordance with applicable legal
requirements.
In light of the knowledge and understanding of the group and parent company and their environment obtained in the course of the audit, we
did not identify any material misstatements in the Strategic report and Directors' Report.
Annual Report On Remuneration
In our opinion, the part of the Annual Report on Remuneration to be audited has been properly prepared in accordance with the Companies
Act 2006.
Responsibilities for the financial statements and the audit
Responsibilities of the directors for the financial statements
As explained more fully in the Statement of Directors' Responsibilities, the directors are responsible for the preparation of the financial
statements in accordance with the applicable framework and for being satisfied that they give a true and fair view. The directors are also
responsible for such internal control as they determine is necessary to enable the preparation of financial statements that are free from
material misstatement, whether due to fraud or error.
In preparing the financial statements, the directors are responsible for assessing the group’s and the parent company’s ability to continue as
a going concern, disclosing, as applicable, matters related to going concern and using the going concern basis of accounting unless the
directors either intend to liquidate the group or the parent company or to cease operations, or have no realistic alternative but to do so.
Auditors’ responsibilities for the audit of the financial statements
Our objectives are to obtain reasonable assurance about whether the financial statements as a whole are free from material misstatement,
whether due to fraud or error, and to issue an auditors’ report that includes our opinion. Reasonable assurance is a high level of assurance,
but is not a guarantee that an audit conducted in accordance with ISAs (UK) will always detect a material misstatement when it exists.
Misstatements can arise from fraud or error and are considered material if, individually or in the aggregate, they could reasonably be expected
to influence the economic decisions of users taken on the basis of these financial statements.
Irregularities, including fraud, are instances of non-compliance with laws and regulations. We design procedures in line with our
responsibilities, outlined above, to detect material misstatements in respect of irregularities, including fraud. The extent to which our
procedures are capable of detecting irregularities, including fraud, is detailed below.
Based on our understanding of the group and industry, we identified that the principal risks of non-compliance with laws and regulations
related to the Companies Act 2006 and UK Tax Legislation, and we considered the extent to which non-compliance might have a material
effect on the financial statements. We evaluated management’s incentives and opportunities for fraudulent manipulation of the financial
statements (including the risk of override of controls), and determined that the principal risks were related to posting inappropriate journal
entries to manipulate revenue and the inappropriate extraction of cash. Audit procedures performed by the engagement team included:
Discussions with management and those charged with governance on known or suspected instances of non-
compliance with laws or regulations, or instances of fraud;
Review of minutes of meeting with the Board of Directors;
Identifying and testing journal entries, in particular any journal entries posted with unusual account combinations that
represent a risk of material misstatement due to fraud and those posted by unexpected users;
Performing unpredictable procedures designed to identify fraud; and
Review of the financial statement disclosures for compliance with the Companies Act 2006 and auditing of tax
balances for compliance with UK legislation, including review of correspondence with tax authorities where relevant.
There are inherent limitations in the audit procedures described above. We are less likely to become aware of instances of non-compliance
with laws and regulations that are not closely related to events and transactions reflected in the financial statements. Also, the risk of not
detecting a material misstatement due to fraud is higher than the risk of not detecting one resulting from error, as fraud may involve deliberate
concealment by, for example, forgery or intentional misrepresentations, or through collusion.

SILENCE THERAPEUTICS PLC
66
Our audit testing might include testing complete populations of certain transactions and balances, possibly using data auditing techniques.
However, it typically involves selecting a limited number of items for testing, rather than testing complete populations. We will often seek to
target particular items for testing based on their size or risk characteristics. In other cases, we will use audit sampling to enable us to draw a
conclusion about the population from which the sample is selected.
A further description of our responsibilities for the audit of the financial statements is located on the FRC’s website at:
www.frc.org.uk/auditorsresponsibilities. This description forms part of our auditors’ report.
Use of this report
This report, including the opinions, has been prepared for and only for the parent company’s members as a body in accordance with Chapter
3 of Part 16 of the Companies Act 2006 and for no other purpose. We do not, in giving these opinions, accept or assume responsibility for
any other purpose or to any other person to whom this report is shown or into whose hands it may come save where expressly agreed by
our prior consent in writing.
Other required reporting
Companies Act 2006 exception reporting
Under the Companies Act 2006 we are required to report to you if, in our opinion:
we have not obtained all the information and explanations we require for our audit; or
adequate accounting records have not been kept by the parent company, or returns adequate for our audit have not
been received from branches not visited by us; or
certain disclosures of directors’ remuneration specified by law are not made; or
the parent company financial statements and the part of the Annual Report on Remuneration to be audited are not
in agreement with the accounting records and returns.
We have no exceptions to report arising from this responsibility.
Fiona Hornsby (Senior Statutory Auditor)
for and on behalf of PricewaterhouseCoopers LLP
Chartered Accountants and Statutory Auditors
Reading
29 April 2025

SILENCE THERAPEUTICS PLC

Consolidated income statement
year ended 31 December 2024

Note
2024
2023

£000s
£000s
Revenue
3
33,833
25,375
Cost of sales
(9,237)
(10,318)
Gross profit
24,596
15,057
Research and development costs
(53,304)
(44,025)
Administrative expenses
(20,325)
(20,636)
Operating loss
5
(49,033)
(49,604)
Finance and other expenses

7
(74)
(2,152)
Finance and other income
8
4,027
1,446
Loss for the year before taxation
(45,080)
(50,310)
Taxation
9
9,838
7,043
Loss for the year after taxation
(35,242)
(43,267)
Loss per ordinary equity share (basic and diluted)
10
(25.4) pence
(38.9) pence

Consolidated statement of comprehensive income
year ended 31 December 2024

2024
2023

£000s
£000s
Loss for the year after taxation

(35,242)

(43,267)
Other comprehensive expense, net of tax:

Items that may subsequently be reclassified to profit and
loss:

Foreign exchange differences arising on consolidation of foreign
operations

(291)

(134)
Total other comprehensive expense for the year

(291)

(134)
Total comprehensive expense for the year

(35,533)

(43,401)

The accompanying accounting policies and notes form an integral part of these financial statements.

SILENCE THERAPEUTICS PLC

Consolidated balance sheet
at 31 December 2024

31 December

Note
2024
2023

£000s
£000s
Non-current assets
Property, plant and equipment
11
1,575
1,813
Goodwill
12
7,492
7,840
Other intangible assets
13
249
284
Other long-term assets
16
2,580
2,580
Financial assets at amortised cost
15
284
284

12,180
12,801
Current assets
Cash and cash equivalents
14
96,786
54,031
Financial assets at amortised cost
15
20,744
-
R&D tax credit receivable
9
19,461
17,627
Other current assets
16
11,698
9,135
Trade receivables
17
775
228

149,464
81,021
Non-current liabilities
Lease liability
19
-
(93)
Contract liabilities
20
(41,313)
(58,910)

(41,313)
(59,003)
Current liabilities
Contract liabilities
20
(244)
(5,161)
Trade and other payables
18
(13,111)
(12,429)
Lease liability
19
(93)
(179)

(13,448)
(17,769)
Net assets
106,883
17,050
Capital and reserves attributable to the owners of the parent
Share capital
22
(7,083)
(5,942)
Capital reserves
24
(435,524)
(313,769)
Translation reserve
(1,660)
(1,951)
Accumulated losses
337,384
304,612
Total shareholders’ equity
(106,883)
(17,050)

The financial statements on page 67 to 100 were approved by the Board on 29 April 2025 and signed on its behalf.

Craig Tooman
Chief Executive Officer
Company number: 02992058
The accompanying accounting policies and notes form an integral part of these financial statements.

SILENCE THERAPEUTICS PLC

Consolidated statement of changes in equity
year ended 31 December 2024

Note
Share
capital
Capital
Reserves
Translation
reserve
Accumulated
losses
Total
equity

£000s
£000s
£000s
£000s
£000s
At 1 January 2023
5,390
277,860
2,085
(263,263)
22,072
Recognition of share-based payments
22
-
13,050
-
-
13,050
Options exercised in the year
24/22
-
(1,918)
-
1,918
-
Proceeds from shares issued
24/22
552
24,777
-
-
25,329
Transactions with owners recognised
directly in equity
552

35,909
-

1,918
38,379
Loss for year
-
-
-
(43,267)
(43,267)
Other comprehensive expense
Foreign exchange differences arising on
consolidation of foreign operations
-

-
(134)

-
(134)
Total comprehensive expense for the year
-
-
(134)
(43,267)
(43,401)
At 31 December 2023
5,942
313,769
1,951
(304,612)
17,050
Recognition of share-based payments
24
-
12,754
-
-
12,754
Options exercised in the year
24
-
(2,470)
-
2,470
-
Proceeds from shares issued
24/22
1,142
111,470
-
-
112,612
Transactions with owners recognised
directly in equity
1,142

121,754
-

2,470
125,366
Loss for year
-
-
-
(35,242)
(35,242)
Other comprehensive expense
-
Foreign exchange differences arising on
consolidation of foreign operations
-

-
(291)

-
(291)
Total comprehensive expense for the year
-
-
(291)
(35,242)
(35,533)
At 31 December 2024
7,084
435,523
1,660
(337,384)
106,883

The accompanying accounting policies and notes form an integral part of these financial statements.

SILENCE THERAPEUTICS PLC

Consolidated statement of cash flows
year ended 31 December 2024

Year ended 31 December

2024
2023

£000s
£000s
Cash flow from operating activities

Loss before tax

(45,080)
(50,310)
Depreciation charges

429
462
Amortisation charges

35
36
Charge for the year in respect of share-based payments

12,754
13,050
Net foreign exchange (gain)/loss

(1,400)
2,157
Finance and other expenses

74
2,152
Finance and other income

(4,027)
(1,446)
(Increase)/Decrease in trade receivables

(707)
314
(Increase)/Decrease in other current assets

(2,563)
610
Increase in R&D Tax Credit Receivable

(244)
(1,772)
Increase in other long term current assets

-
(2,580)
Increase in trade and other payables

533
44
Decrease in contract liabilities

(22,514)
(8,278)
Cash spent on operations

(62,710)
(45,561)
Tax paid

(339)
(642)
R&D tax credits received

8,915
6,853
Net cash outflow from operating activities

(54,134)
(39,350)
Cash flow from investing activities

Redemption of financial assets at amortised cost – term deposits

91,831
36,183
Purchase of financial assets at amortized cost

(108,846)
(20,666)
Interest received

1,523
958
Purchase of property, plant and equipment

(165)
(45)
Net cash inflow from investing activities

(15,657)
16,430
Cash flow from financing activities

Repayment of lease liabilities

(179)
(174)
Proceeds from issue of share capital

119,481
24,315
Transaction costs for issue of share capital

(6,868)
1,014
Net cash inflow from financing activities

112,434
25,155
Increase in cash and cash equivalents

42,643
2,235
Cash and cash equivalents at start of year

54,031
54,816
Effect of exchange rate fluctuations on cash and cash equivalents held

112
(3,020)
Cash and cash equivalents at end of year

96,786
54,031

The accompanying accounting policies and notes form an integral part of these financial statements.

SILENCE THERAPEUTICS PLC

Notes to the consolidated financial statements
year ended 31 December 2024
1.
General information
1.1
Group
Silence Therapeutics plc and its subsidiaries (together the ‘Group’) are primarily involved in the discovery, delivery and
development of RNA therapeutics. Silence Therapeutics plc, a public Company limited by shares registered in England
and Wales, with company number 02992058, is the Group’s ultimate parent Company. The Company’s registered office
is 27 Eastcastle Street, London, W1W 8DH and the principal place of business is 72 Hammersmith Road, London, W14
8TH.

2.
Principal accounting policies
2.1
Basis of preparation
The consolidated financial statements have been prepared in accordance with UK adopted International Accounting
Standards and with the requirements of the Companies Act 2006 as applicable to companies reporting under those
standards. The consolidated financial statements have been prepared under the historical cost convention as modified
by revaluation to fair value of the derivative financial instrument. The accounting policies set out below have, unless
otherwise stated, been prepared consistently for all periods presented in these consolidated financial statements. The
financial statements are prepared in sterling and presented to the nearest thousand pounds.
New and amended standards applicable in year adopted
During the year ended 31 December 2024, we adopted, beginning 1 January 2024, amendments to IAS1 'Presentation
of financial statements' on classification of liabilities. The remaining standards are not applicable to the entity in the
current or future reporting periods and on foreseeable future transactions. This did not have a material impact on the
Company's results of operations or financial position.
New standards issued but not yet effective and not early adopted
Certain new accounting standards and interpretations have been published that are not mandatory for 31 December
2024, reporting periods and have not been early adopted by the Group. These standards are not applicable to the entity
in the current or future reporting periods and on foreseeable future transactions.
New standards issued but not yet effective and early adopted
There were no standards early adopted.

2.2
Basis of consolidation

The Consolidated financial statements consolidate those of the Company and its controlled subsidiary undertakings
drawn up to 31 December 2024. The Group controls an entity when the Group is expected to, or has rights to, variable
returns from its involvement with the entity and has the ability to affect those returns through its power over the entity.
Where necessary, adjustments are made to the financial statements of subsidiaries to bring accounting policies into line
with those used for reporting the operations of the Group. All intra Group transactions, balances, income and expenses
are eliminated on consolidation.

SILENCE THERAPEUTICS PLC

2.3
Going concern
The Group has incurred recurring losses since inception, including net losses of £35.2 million for the year ended 31
December 2024. As of 31 December 2024, the Group had accumulated losses of £337.4 million and cash outflows from
operating activities for the year ended 31 December 2024 of £62.7 million.
The Group expects to incur operating losses for the foreseeable future as it continues its research and development
efforts, seeks to obtain regulatory approval of its product candidates and pursues any future product candidates the
Group may develop.
To date, the Group has funded its operations through upfront payments and milestones from collaboration agreements,
equity offerings and proceeds from private placements, as well as management of expenses and other financing options
to support its continued operations. In 2024, the Group raised additional proceeds of £21.7million ($27.7 million) before
deducting £0.7 million ($0.9 million) in placement agent fees and other expenses, from sales of ADSs under its Sales
Agreement. On 5 February 2024, the Group announced a private placement of 5,714,286 of the Group’s American
Depositary Shares (“ADSs”), each representing three ordinary shares, at a price of $21.00 per ADS, with new and
existing institutional and accredited investors (the “Private Placement”). The aggregate gross proceeds of the Private
Placement was £95.4 million ($120.0 million) before deducting approximately £6.1 million ($7.7 million) in placement
agent fees and other expenses. In 2024, the Group received a £7.9 million ($10.0 million) milestone payment from the
AstraZeneca Collaboration and achieved another £1.6 million ($2.0 million) in milestone payments from the Hansoh
collaboration. As of 31 December 2024, the Group had cash and U.S. treasury bills of £117.5 million ($147.3 million).
The Group believes that its current cash and cash equivalents are sufficient to fund its operating expenses for at least
the next twelve months from the issuance date of these consolidated financial statements. For this reason, the Company
continues to adopt the going concern basis in preparing the financial statements.
The Group will need to raise additional funding to fund its operation expenses and capital expenditure requirements in
relation to its clinical development activities. The Group may seek additional funding through public or private financings,
debt financing or collaboration agreements. Specifically, the Group may receive future milestone payments from existing
collaboration agreements which will extend the ability to fund operations. However, these future milestone payments
are dependent on achievement of certain development or regulatory objectives that may not occur. The inability to obtain
future funding could impact; the Group’s financial condition and ability to pursue its business strategies, including being
required to delay, reduce or eliminate some of its research and development programmes, or being unable to continue
operations or unable to continue as a going concern.
2.4
Research and development
The Group recognise expenditure incurred in carrying out its research and development activities in line with
management’s best estimation of the costs incurred to date for each separately contracted study or activity. This includes
the calculation of research and development accruals at each period to account for expenditure that has been incurred.
This requires estimations of the full costs to complete each study or activity and also estimation of the current stage of
completion. In all cases, the full cost of each study or activity is expensed by the time the final report or, where applicable,
product, has been received. Further details on research and development can be found in note 2.11.

2.5
Revenue recognition

The Group’s revenue for the year ended 31 December 2024 consists of royalty income and revenue from collaboration
agreements.

Royalty income
The Group’s royalty income is generated by a settlement and license agreement with Alnylam. Under this contract,
Alnylam is obliged to pay royalties to the Group on the net sales of ONPATTRO™ in the EU in a manner commensurate
with the contractual terms. Invoices are raised in arrears on a quarterly basis based on sales information provided by
Alnylam no later than 75 days after the quarter end.

SILENCE THERAPEUTICS PLC

(2.5 Revenue Recognition note continued)
The royalty exemption under IFRS 15 requires sales-based data. Royalty revenue is recognised when sales data is
received, based on the level of sales when the related sales occur.

Revenue from collaboration agreements

We have considered the Mallinckrodt, AstraZeneca, and Hansoh contracts and assessed whether the research and
development services and license of the IP in respect of each target are distinct.

For all contracts we have concluded the license of the intellectual property and the R&D services are not distinct, as
Mallinckrodt, AstraZeneca, and Hansoh cannot benefit from the intellectual property absent the R&D services, as those
R&D services are used to discover and develop a drug candidate and to enhance the value in the underlying intellectual
property, and these services could not be performed by another party, indicating that the two are highly interrelated. On
this basis, we have concluded that there is a single performance obligation covering both the R&D services and the
license of the intellectual property in respect of each target. We recognise revenue over the duration of the contract
based on an input method based on cost to cost.

The contracts have mule elements of consideration (some or all of the following), namely:

Upfront payments (fixed);

Subsequent milestone payments (variable);

FTE costs rechargeable (variable);

Recharges of direct costs for certain research activities (variable).

The Group’s effort under the contracts continues throughout their entire duration. On this basis revenue is recognised
over the contract period based on costs to completion.

Revenue has been calculated on the following ongoing basis for the year ended 31 December 2024:

Total contract costs which includes actual FTE and direct costs incurred up to 31 December 2024 and forecast
FTE and direct costs for the remainder of the contract

Actual costs incurred up until 31 December 2024 are calculated as a percentage of total contract costs (actual
and forecast)

This percentage is then multiplied by the transaction price allocated to the performance obligation in question,
thus calculating the cumulative revenue which is then used to calculate the revenue to be recognised in that
period. In the case of the upfront and milestones, the consideration that is multiplied is in relation to the upfront
and completed milestones only. Consideration in relation to milestones not yet achieved is excluded from the
calculation.

SILENCE THERAPEUTICS PLC

(2.5 Revenue Recognition note continued)
Forecast costs are monitored each period, with revenue recognised reflecting any changes in forecast or over/under
spend in actuals.

Further details of the revenue amounts recognised in the year ended 31 December 2024 can be found in note 3.

2.6
Foreign currency translation
The consolidated financial statements are presented in sterling. The individual financial statements of each Group entity
are prepared in the currency of the primary economic environment in which the entity operates (its functional currency).
In preparing the financial statements of the individual entities, transactions in currencies other than the entity’s functional
currency (foreign currencies) are recorded at the rates of exchange prevailing on the dates of the transactions. At each
balance sheet date, monetary items denominated in foreign currencies are retranslated at the rates prevailing on the
balance sheet date.
Exchange differences arising on the settlement of monetary items, and on the retranslation of monetary items, are
included in the income statement for the year.
For the purpose of presenting consolidated financial statements, the assets and liabilities of the Group’s foreign
operations (including comparatives) are translated into sterling using exchange rates prevailing on the balance sheet
date. Income and expense items (including comparatives) are translated at the average exchange rates for the year
unless individually significant to the Group at which point they are translated at spot rate. Exchange differences arising,
if any, are recognised in equity.
2.7
Defined contribution pension funds
The contributions payable to defined contribution retirement schemes are recognised as an expense in the period to
which they relate. On the payment of the contribution the Group has no further liability.
2.8
Business combinations
There were no new business combinations as defined by IFRS 3 during 2023 or 2024.
All goodwill is attributed to an acquisition that occurred in 2005. Goodwill represents the excess of the cost of the
acquisition over the Group’s interest in the recognised amount (generally fair value) of the identifiable assets, liabilities
and contingent liabilities of the acquiree.
2.9
Property, plant and equipment
The Group holds no property assets other than leased property assets classified as right-of-use assets. See note 2.14
for further details.
All equipment and furniture is stated in the financial statements at its cost of acquisition less a provision for
depreciation.
Depreciation is charged to write off the cost less estimated residual values of furniture and equipment on a straight-
line basis over their estimated useful lives. All equipment and furniture is estimated to have a useful economic life of
between three and ten years. Estimated useful economic lives and residual values are reviewed each year and
amended if necessary.

SILENCE THERAPEUTICS PLC

2.10
Goodwill
Goodwill is stated at cost less any accumulated impairment losses; it is allocated to the cash generating unit or operating
segment that is expected to benefit from synergies of the related business combination and represent the lowest level
within the Group at which management controls the related cash flows. Goodwill is not amortised but is tested for
impairment annually, or sooner when an indication of impairment has been identified. Goodwill arising on the acquisition
of a subsidiary represents the excess of the cost of acquisition over the Group’s interest in the net fair value of the
identifiable assets, liabilities and contingent liabilities of the subsidiary at the date of acquisition. On disposal of a
subsidiary, the attributable amount of goodwill is included in the determination of the profit or loss on disposal.
2.11
Other intangible assets
Other intangible assets that are acquired by the Group are stated at cost less accumulated amortisation and less
accumulated impairment losses.
Amortisation
Amortisation is charged to the income statement on a straight-line basis over the estimated useful lives of intangible
assets unless such lives are indefinite. Intangible assets with an indefinite useful life and goodwill are systematically
tested for impairment at each balance sheet date. Other intangible assets are amortised from the date they are available
for use. The estimated useful lives are as follows:
Licences and software 10 – 15 years.
Capitalisation of research and development costs
Costs associated with research activities are treated as an expense in the period in which they are incurred.
Costs that are directly attributable to the development phase of an internal project will only be recognised as intangible
assets provided they meet the following requirements:

an asset is created that can be separately identified;

the technical feasibility exists to complete the intangible asset so that it will be available for sale or use and the
Group has the intention and ability to do so;

it is probable that the asset created will generate future economic benefits either through internal use or sale;

sufficient technical, financial and other resources are available for completion of the asset; and

the expenditure attributable to the intangible asset during its development can be reliably measured.
Careful judgment by management is applied when deciding whether recognition requirements for development costs
have been met. This is necessary as the economic success of any product development is uncertain and may be subject
to future technical problems at the time of recognition. Judgements are based on the information available at each
balance sheet date.
To date, no development costs have been capitalised in respect of the internal projects on the grounds that the costs to
date are either for the research phase of the projects or, if relating to the development phase, then the work so far does
not meet the recognition criteria set out above. In most cases recognition would not occur until regulatory approval.

SILENCE THERAPEUTICS PLC

2.12
Impairment testing of goodwill, other intangible assets and property, plant and equipment
At each balance sheet date non-financial assets are assessed to determine whether there is an indication that the asset
or the asset’s cash generating unit may be impaired. At least annually or if there is such an indication, the recoverable
amount of the asset or asset’s cash generating unit is compared to the carrying amount.
The recoverable amount of the asset or asset’s cash generating unit is the higher of the fair value less costs to sell and
value in use.
Impairment losses recognised for cash generating units to which goodwill has been allocated are credited initially to the
carrying amount of goodwill. Any remaining impairment loss is charged pro rata to the other assets in the cash generating
unit.
2.13
Financial instruments
Financial assets and financial liabilities are recognised on the balance sheet when the Group becomes a party to the
contractual provisions of the instrument.
The de-recognition of financial instruments occurs when the rights to receive cash flows from investments expire or are
transferred and substantially all of the risks and rewards of ownership have been transferred.
Financial assets
Financial assets and financial assets at amortised cost include trade receivables held in order to collect contractual cash
flows, prepayments, U.S. Treasury Bills, term deposits held to collect solely payment of the principal and interest, and
deposits on property operating leases and for the procurement of materials. These are measured at initial recognition
at fair value plus, if appropriate, directly attributable transaction costs and are subsequently measured at amortised cost
using the effective interest method, less provision for impairment. Premiums and discounts, if any, are amortised or
accreted as interest expense or income over the life of the related asset using the effective interest method. Any
impairment is assessed using the Expected Credit Losses (ECL) model. The Group applies the IFRS 9 simplified
approach to measuring expected credit losses which uses a lifetime expected loss allowance for trade receivables. Any
impairment is recognised in the income statement.
Cash and cash equivalents
Cash and cash equivalents comprise cash on hand and demand deposits with original maturities of three months or
less that are readily convertible to a known amount of cash and are subject to an insignificant risk of change in value.
Financial liabilities and equity
Financial liabilities and equity instruments issued are classified according to the substance of the contractual
arrangements entered into and the definitions of a financial liability and an equity instrument. A financial liability is a
contractual obligation to either deliver cash or another financial asset to another entity or to exchange a financial asset
or financial liability with another entity, including obligations which may be settled using its equity instruments. An equity
instrument is any contract that evidences a residual interest in the assets after deducting all of its liabilities. The
accounting policies adopted for specific financial liabilities and equity instruments are set out below.
Financial liabilities
At initial recognition, financial liabilities, including trade and other payables, are measured at their fair value minus, if
appropriate, any transaction costs that are directly attributable to the issue of the financial liability. After initial recognition,
all financial liabilities are measured at amortised cost using the effective interest method.
Equity instruments
Equity instruments issued by the Group are recorded as the proceeds received, net of direct issue costs.

SILENCE THERAPEUTICS PLC
77
2.14
Leased Assets
For any new contracts entered into on or after 1 January 2019, the Group considers whether a contract is, or contains
a lease. A lease is defined as ‘a contract, or part of a contract, that conveys the right to use an asset (the underlying
asset) for a period of time in exchange for consideration’. To apply this definition, the Group assesses whether the
contract meets two key evaluations, which are whether:
the contract contains an identifiable asset;
the Group has the right to obtain substantially all of the economic benefits from use of the identified asset
throughout the period of use
Measurement and recognition
At lease commencement date, the Group recognises a right-of-use asset (as part of the appropriate underlying class of
assets in property, plant and equipment) and a lease liability on the balance sheet.
The right-of-use asset is measured at cost comprising the following: the amount of the initial measurement of lease
liability, any lease payments made at or before the commencement date less any lease incentives received, any initial
direct costs, and restoration costs. The Group depreciates the right-of-use assets on a straight-line basis from the lease
commencement date to the earlier of the end of the useful life of the right-of-use asset or the end of the lease term. The
Group also assesses the right-of-use asset for impairment when such indicators exist.
At the commencement date, the Group measures the lease liability at the present value of the lease payments unpaid
at that date, discounted using the Group’s incremental borrowing rate. Lease payments included in the measurement
of the lease liability are made up of fixed payments (including in substance fixed), variable payments based on an index
or rate, amounts expected to be payable under a residual value guarantee and payments arising from options
reasonably certain to be exercised. Subsequent to initial measurement, the liability will be reduced for payments made
and increased for interest.
The Group has elected to account for short-term leases (leases with a duration of less than 12 months) and leases of
low-value assets using the practical expedients. Instead of recognising a right-of-use asset and lease liability, the
payments in relation to these are recognised as an expense in profit or loss on a straight-line basis over the lease term.
The interest payments for leases are recognised in the statement of cashflows under finance and other expenses.
Lease break clauses and extension options
When the Group has the option to extend a lease, management uses its judgment to determine whether or not an option
would be reasonably certain to be exercised. Management considers all facts and circumstances including past practice
and any cost that will be incurred to change the asset if an option to extend is not taken, to help determine the lease
term.
Similarly, when a break clause exists in the lease agreement, management must consider the likelihood of this option
to curtail the lease being exercised.

SILENCE THERAPEUTICS PLC
78
2.15
Share-based payments
Historically the Group has issued equity settled share-based payments to certain employees (see note 23). Equity
settled share-based payments are measured at fair value (excluding the effect of non-market-based vesting conditions)
at the date of grant. The fair value so determined is expensed on a straight-line basis over the vesting period, based on
the Group of the number of shares that will eventually vest and adjusted for the effect of non-market-based vesting
conditions.
The value of the charge is adjusted to reflect expected and actual levels of award vesting, except where failure to vest
is as a result of not meeting a market condition.
Cancellations of equity instruments are treated as an acceleration of the vesting period and any outstanding charge is
reversed in full immediately.
Fair value is measured using a Black Scholes model or binomial pricing model. The key assumptions used in the model
have been adjusted, based on management’s best estimate, for the effects of non-transferability, exercise restrictions
and behavioural considerations.
Any payment made to a counterparty on the cancellation or settlement of a grant of equity instruments (even if this
occurs after the vesting date) should be accounted for as a repurchase of an equity interest (that is, as a deduction from
equity). But, if the payment exceeds the fair value of the equity instruments repurchased (measured at the repurchase
date), any such excess should be recognised as an expense.
2.16
Equity
Share capital is determined using the nominal value of shares that have been issued.
The share premium account includes any premiums received on the initial issuing of the share capital. Any transaction
costs associated with the issuing of shares are deducted from the share premium account, net of any related income
tax benefits.
The merger reserve represents the difference between the nominal value and the market value at the date of issue of
shares issued in connection with the acquisition by the Group of an interest in over 90% of the share capital of another
company.
Equity settled share-based payments are credited to a share-based payment reserve as a component of equity until
related options or warrants are exercised.
Foreign currency translation differences are included in the translation reserve.
Profit and loss account (deficit) includes all current and prior period results as disclosed in the income statement.
2.17 Taxation
Current tax payable is based on taxable profit for the year. Taxable profit differs from profit as reported in the income
statement because it excludes items of income or expense that are taxable or deductible in other years and it further
excludes items that are never taxable or deductible. Current tax liabilities are calculated using tax rates that have been
enacted or substantively enacted by the balance sheet date.

SILENCE THERAPEUTICS PLC

(2.17 Taxation note continued)
Tax receivable arises from the U.K. legislation regarding the treatment of certain qualifying research and development
costs, allowing for the surrender of tax losses attributable to such costs in return for a tax rebate. Research and
development tax credits are recognised when the receipt is probable.

Deferred tax is recognised on differences between the carrying amounts of assets and liabilities in the financial
statements and the corresponding tax bases used in the computation of taxable profit and is accounted for using the
balance sheet liability method. Deferred tax liabilities are generally recognised for all taxable temporary differences and
deferred tax assets are recognised to the extent that it is probable that taxable profits will be available against which
deductible temporary differences can be utilised.

Such assets and liabilities are not recognised if the temporary difference arises from initial recognition of goodwill or
from the initial recognition (other than in a business combination) of other assets and liabilities in a transaction that
affects neither the taxable profit nor the accounting profit.

Deferred tax liabilities are recognised for taxable temporary differences arising on investments in subsidiaries except
where the Group is able to control the reversal of the temporary difference and it is probable that the temporary difference
will not reverse in the foreseeable future.

The carrying amount of deferred tax assets is reviewed at each balance sheet date and reduced to the extent that it is
no longer probable that sufficient taxable profits will be available to allow all or part of the asset to be recovered.
Deferred tax is calculated at the tax rates that are expected to apply in the period when the liability is settled, or the
asset realised. Deferred tax is charged or credited to the income statement, except when it relates to items charged or
credited directly to equity, in which case the deferred tax is also dealt with in equity.

Deferred tax assets and liabilities are offset when there is a legally enforceable right to set off current tax assets against
current tax liabilities and when they relate to income taxes levied by the same taxation authority and the Group intends
to settle its current tax assets and liabilities on a net basis.

Withholding tax is payable on gross income from dividends, interest, lease of property, royalties, and other China-source
passive income since the Group does not have an establishment or place of business in China.

2.18
Critical accounting estimates and judgements and key sources of estimation uncertainty
In the process of applying the entity’s accounting policies, management makes estimates and judgments that have an
effect on the amounts recognised in the financial statements. Although these estimates are based on management’s
best knowledge of current events and actions, actual results may ultimately differ from those estimates.
The critical judgments concerning the future, and other key sources of estimation uncertainty at the balance sheet date,
that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the
next financial year, are described below:

Application of IFRS 15 in determining revenue from contracts with customers specifically:

o
The determination of the numbers of performance obligations. Judgement was previously required in
determining whether the license and the R&D activities are distinct performance obligations or not at the
time the collaboration agreements were executed. It is considered the license of the IP and the R&D
activities are not distinct as the R&D services are essential to discover and develop a drug candidate and
enhance the value in the underlying IP. In addition, the gene targets are highly specialised such that only

SILENCE THERAPEUTICS PLC

the Group has the specialist knowledge to apply the IP to the specific target. On this basis, it was concluded
that there is only one single performance obligation covering both the R&D services and licenses of the IP
in respect of each target at the time the agreements were executed;
o
The allocation of the upfront payments between performance obligations (judgement). Mallinckrodt paid
the Group $20 million in 2019, AstraZeneca have paid the Group $60 million in 2020 and 2021, and Hansoh
paid $16 million upfront under their respective contracts, which is in 2021. A judgment was required to
determine how this should be allocated across the contracted targets. In 2019, due to the compounds being
at similar stages of development at the time of contract execution, the $20 million paid by Mallinckrodt was
allocated evenly, on the basis of a benchmarking exercise considering the standalone selling price per
target of past deals announced to the market by comparable companies; similarly it was concluded that the
$60 million amount to be paid by AstraZeneca was allocated evenly across target options for AstraZeneca.
The Hansoh $16 million upfront payment was allocated $4 million for each of the two targets in Greater
China, Hong Kong, Macau and Taiwan and $8 million for the global target based on the benchmarking
exercise, as well as consideration for geography licensed and other contractual terms. These initial
transaction amounts are recognized as revenue over the life of the performance obligations for each
contract.

Recognition of Clinical trial expenses: As part of the process of preparing our consolidated financial statements,
we may be required to estimate accrued expenses related to our preclinical studies and clinical trials. To obtain
reasonable estimates, we review open contracts and purchase orders. In addition, we communicate with applicable
personnel in order to identify services that have been performed, but for which we have not yet been invoiced. In most
cases, our vendors provide us with monthly invoices in arrears for services performed. We confirm our estimates with
these vendors and make adjustments as needed. Examples of our accrued expenses include fees paid to CROs for
services performed on preclinical studies and clinical trials and fees paid for professional services.
2.19
Segment reporting

Operating segments are reported in a manner consistent with the internal reporting provided to the Board. The chief
operating decision maker (CODM), who is responsible for allocating resources and assessing performance of the
operating segments, has been identified as the Group’s Chief Executive Officer. The Group has a single reportable
segment (see note 4).

3.
Revenue
Revenue from collaboration agreements for the year ended 31 December 2024 relates to the Research collaboration
agreements the Group entered into with Mallinckrodt plc in July 2019, AstraZeneca plc in March 2020, and Hansoh in
October 2021.
Revenue comprised £0.1 million of royalty income (2023: £0.6 million) and £33.7 million of Research collaboration
income (2023: £24.8 million). Disaggregation of Revenue from Contracts with Customers is as follows:

2024
2023
Revenue from Contracts with Customers

£000s
£000s
Research collaboration - Mallinckrodt plc

457
10,544
Research collaboration - AstraZeneca

14,045
13,682
Research collaboration – Hansoh

19,218
580
Research collaboration – total

33,720
24,806
Royalties

113
569
Total revenue from contracts with customers

33,833
25,375

(2.18 Critical accounting estimates and judgements and key sources of estimation uncertainty note continued)

SILENCE THERAPEUTICS PLC

(3 Revenue note continued)
Under our collaboration agreement with Mallinckrodt, we received an upfront cash payment of £16.4 million ($20 million)
in 2019 and are eligible to receive specified development, regulatory and commercial milestone payments. No milestone
payments under this agreement were achieved (2023: nil) during the year ended December 31, 2024. We recognize the
upfront payment, milestone payments, payments for personnel costs and other research funding payments over time,
in accordance with IFRS 15 para 35 c).
In March 2023, the Company reacquired exclusive worldwide rights to two preclinical siRNA assets under its Mallinckrodt
collaboration, which resulted in a modification of the agreement. No additional performance obligations were identified
as a result of the modification as there were no additional goods or services to be provided by the Company and the
modification resulted in the partially satisfied performance obligations relating to the two reacquired targets becoming
fully satisfied as the Company was no longer obligated to develop these targets. SLN501, the C3 targeting programme,
remains under the original collaboration agreement. The Company accounted for the modification as if it were part of
the existing contract as the remaining services to be delivered form part of a single performance obligation that is partially
satisfied at the date of contract modification. The effect of the contract modification was that the consideration originally
received for the two preclinical siRNA assets was reallocated to SLN501. The Company recognized the effect of the
contract modification on the measure of progress towards complete satisfaction of the SLN501 performance obligation
and recognized an adjustment to revenue at the date of the contract modification on a cumulative catch-up basis. The
Company recognized £8.0 million on the contract modification date. In relation to the reacquired targets, the two
preclinical siRNA assets were recognized at fair value. The fair value of those assets has been determined to be nil.
Under the modification, the Company agreed to pay future success-based milestones and low single digit royalties on
net sales if the projects advance. The Company will recognize these variable success-based milestones as an intangible
asset at cost when triggered. Any royalties payable will be expensed in cost of sales.
In March 2024, Mallinckrodt notified the Group that it will not pursue further development of the SLN501 programme
following the completion of the Phase 1 clinical trial. The completion of the Phase 1 clinical trial also represented the
conclusion of all required development activities and commitments under the terms of the Mallinckrodt Collaboration.
During the year ended 31 December 2024, the Group recognized a total of £0.5 million in revenue under this agreement
(2023: £10.5 million).
Under our collaboration agreement with AstraZeneca, we received an upfront cash payment of £17.1 million ($20 million)
in 2020 with a further amount of £30.8 million ($40 million) received in May 2021. We are also eligible to receive specified
development and commercial milestone payments as well as tiered royalties on net sales, if any. We recognize the
upfront payment and milestone payments over time, in accordance with IFRS 15 para 35 c). During the year ended 31
December 2024, the Company achieved a milestone payment of approximately £7.9 million ($10.0 million) (2023: £7.9
million). During the year ended 31 December 2024, we recognized a total of £14.0 million in revenue under this
agreement (2023: £13.7 million).
We entered into a collaboration agreement with Hansoh on 15 October 2021. We received a $16 million (equivalent to
approximately £11.9 million based on the exchange rate at the payment date and $14.4 million or £10.7 million, net of
taxes) upfront payment to us in December 2021. We are eligible to receive development, regulatory and commercial
milestones as well as royalties on Hansoh net product sales. During the year ended 31 December 2024, the Company
achieved milestone payments totaling £1.6 million ($2.0 million) (2023: £3.2 million). We recognize the upfront payment
and milestone payments over time, in accordance with IFRS 15 para 35 c).
In December 2024, Hansoh notified the Group that it will not pursue further development under the Hansoh
Collaboration. This represented the conclusion of all required development activities and commitments under the terms
of the Hansoh Collaboration. During the year ended 31 December 2024, we recognized a total of £19.2 million in revenue
under this agreement (2023: £0.6 million).
In December 2018, we entered into a settlement and license agreement with Alnylam Pharmaceuticals Inc., or Alnylam,
pursuant to which we settled outstanding patent litigation with Alnylam related to its RNAi product ONPATTRO. As part
of the settlement, we license specified patents to Alnylam, and Alnylam pays us a tiered royalty of up to one percent of
net sales of ONPATTRO in the European Union. We were eligible to receive these royalties through December 2023.
We invoice Alnylam quarterly in arrears based on sales data for that quarter as reported to us by Alnylam. Royalty
revenue is recognized based on the level of sales when the related sales occur. During the year ended 31 December
2024, we recognized a total of £0.1 million in royalty income from Alnylam (2023: £0.6 million).

SILENCE THERAPEUTICS PLC

4.
Segment reporting

In 2024, the Group operated in the specific technology field of RNA therapeutics.

Business segments

The Group has identified the Chief Executive Officer as the CODM. For the 12 months ended 31 December 2023 and
2024, the CODM determined that the Group had one business segment, the development of RNAi-based medicines.
This is in line with reporting to senior management. The information used internally by the CODM is the same as that
disclosed in the financial statements.

An analysis of the Group’s assets and revenues by location is shown below:

U.S.A.
U.K.
Germany
Total

£000s
£000s
£000s
£000s
Non-current assets

As at 31 December 2023

-
3,508
9,293
12,801
As at 31 December 2024

-
3,273
8,907
12,180

Revenue analysis for the year ended 31 December 2023

Research collaboration

-
24,806
-
24,806
Royalties

-
-
569
569

-
24,806
569
25,375

Revenue analysis for the year ended 31 December 2024

Research collaboration

-
33,720
-
33,720
Royalties

-
-
113
113

-
33,720
113
33,833

5.
Operating loss
This is stated after charging:

2024
2023

£000s
£000s
Depreciation of property, plant and equipment

429
462
Amortisation of intangibles

35
36
Share-based payments charge

12,754
13,050
Short lease payments on premises

576
481
Fees payable to the Company's auditors for the audit of the Company and the consolidation:

- audit fees

1,283
576
- other assurance services

371
222

SILENCE THERAPEUTICS PLC

6.
Directors and staff costs
Staff costs, including Directors’ remuneration, during the year for the Group were as follows:

2024
2023

£000s
£000s
Wages and salaries

15,200
15,363
Social security costs

1,364
1,524
Other pension costs

521
489
Share-based payments charge

12,754
13,050
Total aggregate remuneration

29,839
30,426

Remuneration and share based payments detail for all Directors is presented in the Remuneration Committee report.
See page 32 for further details.

2024
2023

Number
Number
Research and development and related support services

85
86
Administration

31
29
Total average number of employees

116
115

7.
Finance and other expenses

2024
2023

£000s
£000s
Lease liability interest expense and other expense

74
34
Net foreign exchange losses

-
2,118
Total Finance and other expenses

74
2,152

8.
Finance and other income

2024
2023

£000s
£000s
Bank interest and accretion on U.S. Treasury Bills

3,521
1,446
Net foreign exchange gains

506
-
Total Finance and other income

4,027
1,446

SILENCE THERAPEUTICS PLC

9.
Taxation
The entire tax credit of £9.8 million (2023: £7.0 million) relates to current tax as shown below. No deferred tax was
recognised in the year.
The deferred tax charge in 2024 was nil (2023: nil). Reconciliation of tax credit at standard rate of U.K. corporation tax
to the current tax credit:

2024
2023

£000s
£000s
Loss before tax

(45,080)
(50,310)
Tax credit at the standard rate of U.K. corporation tax of 25% (2023: 25%)

11,270
12,578
Effect of overseas tax rate

241
207
Impact of unrelieved tax losses not recognised

(12,014)
(13,177)
Adjustment in respect of prior year

-
15
Research and development tax credit in respect of current year

10,499
7,793
Effect of overseas taxes

(158)
(373)

9,838
7,043

Estimated tax losses of £168.0 million (2023: £172.3* million) are available for relief against future profits.
*This disclosure as been adjusted for a prior period error.
The deferred tax asset not recognized in these financial statements on the estimated losses and the treatment of the
equity settled share- based payments, net of any other temporary differences is detailed in note 23. During the year the
Group has accrued £19.4 million in research and development tax credits, £10.7 million relates to 2024 and £8.7 million
is the 2023 research and development tax credit which the Group has not yet received. (2023: £7.8 million). Research
and development tax credit in respect of the current year includes amounts for unfunded projects that are permissible
to claim under the Small or Medium Enterprise ('SME') R&D tax scheme. In addition to this we have also recognised
£0.3 million of income from the RDEC scheme in the income statement within research and development costs (2023:
£0.9 million). The company had a foreign tax expense of £0.5 million. (2023: £0.4 million).
The corporation tax main rate during 2024 was 25% (2023: 25%). The amount of tax credit for 2024 includes the impact
of the changes in credit rates enacted as part of Finance Act 2024. Amendments to the U.K. R&D tax credit regime
included in Finance Act 2024, which was enacted in February 2024, increased the cash rebate that may be claimed
from such date to 26.97% of qualifying expenditure, if we qualify as “R&D intensive” for an accounting period (broadly,
a loss making SME whose relevant R&D expenditure represents 40% for accounting periods beginning on or after 1
April 2023, or 30% for accounting periods beginning on or after 1 April 2024, of its total expenditure for that accounting
period).
Since the Group does not have an establishment or place of business in China, the Group is subject to withholding tax
on gross income from dividends, interest, lease of property, royalties, and other China-source passive income. In 2021
the Group entered into a collaboration agreement with Hansoh, a biopharmaceutical company in China and received a
$16 million upfront payment, which required withholding tax of $1.6 million. In 2023 the Group received a milestone
payment of £3.2 million ($4.0 million), which required withholding tax of £0.4 million. In 2024 the Group received a
milestone payment of £1.6 million ($2.0 million), which required withholding tax of £0.2 million.

SILENCE THERAPEUTICS PLC
85
10.
Loss per ordinary equity share (basic and diluted)
The calculation of the loss per share is based on the loss for the financial year after taxation and on the weighted
average of 138,752,224 (2023: 111,277,250) ordinary shares in issue during the year.
The options outstanding at 31 December 2024 and 31 December 2023 are considered to be anti-dilutive as the Group
is loss-making.
11
Property, plant and equipment
Equipment and
furniture
Right-of-use
asset
Total
£000s
£000s
£000s
Cost
At 1 January 2023
4,986
498
5,484
Additions
45
-
45
Disposals
-
-
-
Translation adjustment
24
5
29
At 31 December 2023
5,055
503
5,558
At 1 January 2024
5,055
503
5,558
Additions
165
-
165
Disposals
(209)
-
(209)
Translation adjustment
49
-
49
At 31 December 2024
5,060
503
5,563
Accumulated depreciation
At 1 January 2023
3,237
46
3,283
Charge for the year
296
166
462
Eliminated on disposal
-
-
-
At 31 December 2023
3,533
212
3,745
At 1 January 2024
3,533
212
3,745
Charge for the year
263
166
429
Eliminated on disposal
(186)
-
(186)
At 31 December 2024
3,610
378
3,988
Net book value
As at 31 December 2023
1,522
291
1,813
As at 31 December 2024
1,450
125
1,575
12.
Goodwill
2024
2023
£000s
£000s
Balance at start of year
7,840
8,009
Translation adjustment
(348)
(169)
Balance at end of year
7,492
7,840

SILENCE THERAPEUTICS PLC
86
(12 Goodwill note continued)
The recoverable amount is based on fair value less cost of disposal.
The key assumptions used in the valuation models to determine the fair value less cost of disposal are as follows:
Fair value has been determined as market capitalisation (share price x number of shares in issue) at 31
December 2024
Disposal costs have been estimated to be minimal
Goodwill is assessed at a segment level. As there is only one operating segment, we have considered the fair value of
the entire business as market capitalization at 31 December 2024, which was £259.2 million (2023: £540.5 million).
13.
Other intangible assets
Licenses &
software
£000s
Cost
At 1 January 2023
430
Additions
-
At 31 December 2023
430
At 1 January 2024
430
Additions
-
Disposals
(46)
At 31 December 2024
384
Accumulated depreciation
At 1 January 2023
110
Charge for the year
36
At 31 December 2023
146
At 1 January 2024
146
Charge for the year
35
Eliminated on disposal
(46)
At 31 December 2024
135
Net book value
As at 31 December 2023
284
As at 31 December 2024
249
The intangible assets included above have finite useful lives estimated to be of 3–10 years from the date of acquisition,
over which period they are amortised or written down if they are considered to be impaired. Internally generated patent
costs are only recorded where they are expected to lead directly to near-term revenues, none have been capitalised to
date.

SILENCE THERAPEUTICS PLC
87
14.
Cash and cash equivalents
2024
2023
£000s
£000s
Cash at bank and in hand
45,142
24,993
U.S. Treasury Bills
51,644
29,038
Total Cash and cash equivalents
96,786
54,031
Cash at bank comprises balances held by the Group in current, U.S. Treasury Bills and short-term bank deposits with
an original maturity of three months or less. The carrying amount of these assets approximates to their fair value.
15.
Financial assets at amortised cost
Non-current financial assets at amortized cost primarily relate to deposits for properties.
Current financial assets at amortized cost, other than trade receivables as disclosed in note 17, include U.S. Treasury
Bills (with maturities from purchase date over three months).
2024
2023
£000s
£000s
Financial assets at amortised cost – U.S. Treasury Bills
20,744
-
Total current financial assets at amortised cost
20,744
-
Non-current financial assets at amortised cost
284
284
Total financial assets at amortised cost
21,028
284
16.
Other assets
2024
2023
£000s
£000s
Prepayments
10,470
8,157
VAT receivable
1,228
978
Total other current assets
11,698
9,135
Long term prepayment
2,580
2,580
Total long-term assets
2,580
2,580
At December 31, 2024 and 2023, the largest component of prepayments are prepaid third party costs for clinical trials,
as well as manufacturing for clinical supplies and associated development, and pre-clinical studies which fluctuate
based on timing of payments and related expense.
Included within prepayments at December 31, 2024 and 2023 is £8.7 million and £6.8 million respectively, are
expenditures relating to research and development.

SILENCE THERAPEUTICS PLC
88
17.
Trade receivables
2024
2023
£000s
£000s
Trade receivables
775
228
The Directors consider that the carrying amount of trade receivables approximates to their fair value.
No interest is charged on outstanding receivables. There were no overdue trade receivables balances.
The Group has applied an expected credit loss model to the balance and determined that £nil (2023: £nil) provision is
required.
18.
Trade and other payables
2024
2023
£000s
£000s
Trade payables
2,949
2,629
Social security and other taxes
195
577
Accruals and other payables
9,447
8,850
Corporate income tax payable
520
373
Total trade and other payables
13,111
12,429
The Directors consider that the carrying amount of trade and other payables approximates to their fair value.
Included within accruals and other payables at December 31, 2024 and 2023 is £4.7 million and £4.4 million respectively,
are expenditures relating to research and development.
19.
Lease liability
The lease liability recognised on the face of the balance sheet comprises of the Group’s London office, which was
renegotiated upon completion of the original term, with the new term beginning in September 2022. The repayment of
the principal portion of these lease liabilities for the year-ending 31 December 2024, was £0.2 million (2023: £0.2 million).
There are two short-term leases in Berlin, Germany and seven leases in Hoboken, U. S., not included in the lease
liability above. Both leases in Berlin are on a rolling contract basis with either party being able to end the lease with a
cancellation notice period of 11.5 months, while the leases in the U. S. are on a rolling contract basis with a notice period
of three months, thus allowing exemption using the practical expedient, without significant cost.
2024
2023
£000s
£000s
Lease liability – current
93
179
Lease liability – non-current
-
93
Total lease liability
93
272

SILENCE THERAPEUTICS PLC

20. Contract liabilities
Contract liabilities comprise entirely deferred revenue in respect of the AstraZeneca plc collaboration. The current
contract liabilities represent the amount of estimated revenue to be reported in the next 12 months related to amounts
invoiced to our partners. Current and non-current contract liabilities include future revenue from collaboration recharged
expenses, upfront payments, and milestones achieved to 31 December 2024.

21.
Deferred tax
The Group has the following unrecognised deferred tax assets as at 31 December 2024:

2024
2023

Gross
Gross

£000s
£000s
Trading losses
169,000
172,323*
Share based payments
730
7,679
Capital losses
7,873
7,873
Total unrecognised deferred tax asset
177,603
187,875

*This disclosure has been adjusted for a prior period error.

31 December,

2024
2023

£000s
£000s
Contract liabilities:

Current

244
5,161
Non-current

41,313
58,910
Total contract liabilities

41,557
64,071

Total

£000s

Contract liabilities:

At 1 January 2023

72,349

Additions during period

16,528
Revenue unwound during period

(24,806)
At 31 December 2023

64,071
At 1 January 2024

64,071

Additions during period

11,206
Revenue unwound during period

(33,720)

At 31 December 2024

41,557

SILENCE THERAPEUTICS PLC

(21 Deferred Taxation note continued)
Total unrecognised deferred tax assets are calculated based on the main corporate tax rate of 25% (25% for 2023) as
this is the rate applicable to when we expect to utilise these deferred tax assets. Unrecognised deferred tax assets from
foreign trading losses are calculated at the tax rate applicable to the related jurisdiction.
Deferred tax assets are recognised where it is probable that future taxable profit will be available to utilise losses. Due
to the uncertainty of future capital gains, a deferred tax asset in respect of capital losses was not recognised at 31
December 2024 (2023: nil).
22.
Share capital

2024
2023

£000s
£000s
Authorised, allotted, called up and fully paid ordinary shares, par value £0.05
7,083
5,942

Number
Number
Number of shares in issue
Number of ADS in issue

141,674,074
47,224,691
118,846,966
39,615,655

The Group has only one class of share. All ordinary shares have equal voting rights and rank pari passu for the
distribution of dividends.
On October 15, 2021, we entered into an Open Market Sale Agreement (the "Sales Agreement"), with Jefferies LLC
("Jefferies"), under which Jefferies, as our exclusive agent, at our discretion and at such times that we may determine
from time to time, may sell over a three-year period from the execution of the Sales Agreement up to a maximum of
$100.0 million of ADSs. During the year ended December 31, 2023, we sold 3.4 million ADSs for net proceeds of £25.5
million ($32.2 million), before deducting £0.7 million ($1.0 million) in placement agent fees and other expenses. In 2024,
the Group raised additional proceeds of £21.7 million ($27.7 million) before deducting £0.7 million ($0.9 million) in
placement agent fees and other expenses, from sales of ADSs under its Sales Agreement. On 22 October 2024, the
Group filed a new registration statement on Form F-3 which replaced the registration statement originally filed on 15
October 2021, for the issuance and sale, if any, of up to an additional $100 million of its shares represented by ADSs
under the Sales Agreement. As of this filing, approximately $139.6 million of ADSs remained.
On 5 February 2024, the Group announced a private placement of 5,714,286 of the Group’s American Depositary
Shares (“ADSs”), each representing three ordinary shares, at a price of $21.00 per ADS, with new and existing
institutional and accredited investors (the “Private Placement”). The aggregate gross proceeds of the Private Placement
was £95.4 million ($120.0 million) before deducting approximately £6.1 million ($7.7 million) in placement agent fees
and other expenses.
Details of the shares issued during the current and previous year are as follows:

SILENCE THERAPEUTICS PLC

(22 Share Capital note continued)

Number of shares in issue at 1 January 2023
107,808,472
Shares issued during the year

10,230,567
Options exercised at $0.20/ADS or $0.07/ordinary share
583,857
Options exercised at $2.40/ADS or $0.80/ordinary share
39,999
Options exercised at $3.76/ADS or $1.25/ordinary share
27,498
Options exercised at $7.60/ADS or $2.53/ordinary share
154,386
Options exercised at $15.38/ADS or $5.13/ordinary share
2,187
Number of shares in issue at 31 December 2023
118,846,966
Number of ADS in issue at 31 December 2023
39,615,655
Shares issued during the year
21,418,665
Options exercised at $0.20/ADS or $0.07/ordinary share
252,540
Options exercised at $2.40/ADS or $0.80/ordinary share
268,791
Options exercised at $4.23/ADS or $1.41/ordinary share
12,000
Options exercised at $4.24/ADS or $1.41/ordinary share
9,999
Options exercised at $5.81/ADS or $1.94/ordinary share
375
Options exercised at $7.32/ADS or $2.44/ordinary share
30,000
Options exercised at $7.60/ADS or $2.53/ordinary share
584,316
Options exercised at $8.20/ADS or $2.73/ordinary share
49,998
Options exercised at $9.98/ADS or $3.33/ordinary share
222
Options exercised at $10.68/ADS or $3.56/ordinary share
10,500
Options exercised at $12.81/ADS or $4.27/ordinary share
1,500
Options exercised at $12.94/ADS or $4.31/ordinary share
2,841
Options exercised at $13.80/ADS or $4.60/ordinary share
3,708
Options exercised at $15.38/ADS or $5.13/ordinary share
126,144
Options exercised at $16.64/ADS or $5.55/ordinary share
1,248
Options exercised at $19.50/ADS or $6.50/ordinary share
780
Options exercised at $20.41/ADS or $6.80/ordinary share
10,500
Options exercised at $22.01/ADS or $7.34/ordinary share
37,545
Options exercised at $23.60/ADS or $7.87/ordinary share
5,436
Number of shares in issue at 31 December 2024
141,674,074
Number of equivalent ADS in issue at 31 December 2024
47,224,691

SILENCE THERAPEUTICS PLC

(22 Share Capital note continued)

At 31 December 2024, there were options outstanding over 17,455,389 (2023: 15,853,459) unissued ordinary shares.
Details of the options outstanding are as follows:
Year of issue
Weighted average
Exercise price (£)
Weighted
average
Exercise
price ($)

At 1 January
2024
Options
granted
Options
forfeited
Options expired
Options
exercised
At 31
December,
2024
Weighted
average years
to expiry date
2014
3.31
4.23

4,000
-
-
- (4,000)
-
-
2015
3.31
4.23

3,333
-
-
-
-
3,333
0.51
2016
4.02
5.14

9,857
-
-
-
(3,333)
6,524
1.19
2017
6.30
8.05

39,999
-
-
-
(16,666)
23,333
2.92
2018
0.16
0.20

36,596
-
-
-
(6,003)
30,593
3.26
2019
4.19
5.36

577,698
-
-
-
(347,701)
229,997
4.77
2020
6.44
8.23

261,207
-
(532)
-
(26,497)
234,178
5.42
2021
17.50
22.37

662,344
-
(7,691)
(62,502)
(16,015)
576,136
6.25
2022
2023
14.46
10.86
18.49
13.88

1,419,863
2,269,589
-
-
(27,309)
(63,858)
(75,037)
(15,127)
(7,019)
(42,247)
1,310,498
2,148,357
7.33
8.20
2024
14.12
18.05

-
1,267,514
(12,000)
-
-
1,255,514
9.06
Total

5,284,486
1,267,514
(111,390)
(152,666)
(469,481)
5,818,463

Number of equivalent ADS

15,853,459
3,802,542
(334,170)
(457,998)
(1,408,443)
17,455,390

ADSs represent three ordinary shares and the exercise price was also converted to represent an ADS price at an
exchange rate equal to the closing current year currency conversion of sterling pounds to US dollars, which was 1.25
sterling pounds to 1 US Dollar.

23.
Equity-settled share-based payments
The Group has issued share options under the 2018 Long Term Incentive Plan (EIP), 2018 Non-Employee Long Term
Inventive Plan (Non-Employee EIP), and individual share option contracts, open to all employees of the Group, as well
as EMI shares (none of which remain outstanding at 31 December 2024). Under the EIP, Non-Employee EIP, individual
contracts and schemes available, the options typically vest after 3 years, with the exception of some options granted to
certain members of key management personnel. The vesting period for these options ranges from 3 to 33 months. The
options usually lapse after one year following the employee leaving the Group.

SILENCE THERAPEUTICS PLC

(23 Equity-settled share-based payments note continued)

2024

2023

Number of

Weighted

Number of
shares

Weighted
ADSs
Average
Average

Average
Exercise
Exercise

Exercise
price
price

price

$
Pence

Pence
Options

Outstanding at the beginning of
the year

5,284,486

14.80

385.85

11,571,486

403.63
Granted during the year

1,267,514

18.05
470.58
7,703,826
374.49
Lapsed or forfeited during the
year

(264,056)

19.82

516.72

(2,613,927)

494.51
Exercised during the year

(469,481)

6.55

170.76
(807,927)

50.52
Outstanding at the year-end
(ordinary shares/pence)

0.00

0.00
Outstanding at the year-end
(ADS/$)
5,818,463

15.95

415.83

15,853,458

395.61
Exercisable at the year-end

2,870,106

15.94

415.57
7,261,842

383.31

The table above shows the number of options in relation to ordinary shares and equivalent ADSs outstanding and
exercisable at year end, on the conversion ratio of three ordinary share options to one ADS as disclosed in Note 24.
The options outstanding at the year-end have a weighted average remaining contractual life of 7.7 years (2023: 7.7
years.
The Group granted 3,802,542 share options during the year (2023: 7,703,826). The fair value of options granted were
calculated using Black Scholes model for 2024 and 2023. Inputs into the model were as follows:

2024
2023
Inputs and assumptions for options granted in the year

Weighted average share price (pence)

470.6
375.0
Weighted average ADS price ($)

18.1
14.0
Weight average hurdle price (pence)

n/a
n/a
Weighted average exercise price (pence)

470.6
375.0
Weighted average ADS price ($)

18.1
14.0
Option life (years)

6.2
6.0
Expected volatility

74.4%-78.6%
72%-79%
Risk free rate

3.39%-3.97%
3.16%-4.43%
Expected dividend yield

nil
nil

The Group recognized total charges of £12.8 million (2023: £13.1 million) related to equity settled share-based
payment transactions during the year.

SILENCE THERAPEUTICS PLC

(23 Equity-settled share-based payments note continued)

The volatility used in our Black Scholes model is based on our historical share price volatility.
The Group does not bear any responsibility to settle any employee tax obligations that arise on the exercise of share
options. The estimated employer tax obligation on outstanding options at the year-end was nominal (2023: £0.2
million).
24.
Capital reserves
The capital redemption reserve was created in 2012 following the reduction of nominal share capital to 0.1p per share.
It is required under Section 733 of the Companies Act 2006, held to maintain the capital of the Company when shares
are bought back and subsequently cancelled without court approval.
Due to the size of the deficit on the accumulated losses account, the Company has no distributable reserves.
The share premium account reflects the premium to nominal value paid on issuing shares less costs related to the issue.
The merger reserve was created on issuance of shares relating to the acquisition of Silence Therapeutics GmbH.
The share-based payments reserve reflects the cost to issue share-based compensation, primarily employee share
options.

Share
Premium
account
Merger
reserve
Share-based
Payment
reserve
Capital
redemption
reserve
Total

£000s
£000s
£000s
£000s
£000s
At 1 January 2023
226,670
22,248
23,748
5,194
277,860
Shares issued
25,411
-
-
-
25,411
On options in issue during the year
-
-
13,050
-
13,050
On options exercised during the year
381
-
(1,918)
-
(1,537)
Costs capitalised in respect of issuance of shares during the
period.
(1,015)
-
-
-
(1,015)
Movement in the year
24,777
-
11,132
-
35,909
At 31 December 2023
251,447
22,248
34,880
5,194
313,769
Shares issued
115,995
-
-
-
115,995
On options in issue during the year
-
-
12,754
-
12,754
On options exercised during the year
2,344
-
(2,470)
-
(126)
Costs capitalised in respect of issuance of shares during the
period.
(6,868)
-
-
-
(6,868)
Movement in the year
111,471
-
10,284
-
121,755
At 31 December 2024
362,918
22,248
45,164
5,194
435,524

25.
Capital commitments and contingent liabilities
There were no capital commitments at 31 December 2024 (2023: nil).

SILENCE THERAPEUTICS PLC

26.
Commitments under short leases
At 31 December 2024, the Group had a gross commitment on its office rental and service charge in Berlin, Germany
and the Hoboken, U.S. lease equal to £0.4 million (2023: £0.4 million) in the next year. No amounts are payable after
more than one year.
In addition, the Group enters into contracts in the normal course of business with contract research organisations to
assist in the performance of research and development activities and other services and products for operating
purposes. These contracts generally provide for termination on notice, and therefore are cancellable contracts and not
reflected in the disclosure above.

27.
Financial instruments and risk management
The Group’s financial instruments comprise primarily cash and other financial assets and various items such as
receivables and trade payables which arise directly from its operations. The main purpose of these financial instruments
is to provide working capital for the Group’s operations. The Group assesses counterparty risk on a regular basis. Board
approval is required for adoption of any new financial instrument or counterparty. The primary focus of the treasury
function is preservation of capital.
The Directors consider that the carrying amount of these financial instruments approximates to their fair value.

Financial assets by category
The categories of financial assets included in the balance sheet and the heading in which they are included are as
follows. The measurement of financial assets is at amortised cost unless otherwise stated:

Financial liabilities by category

All amounts are short-term

2024
2023

£000s
£000s
Trade receivables

775
228
Cash and cash equivalents

96,786
54,031
Financial assets at amortised cost

20,744
-
Non-current financial assets at amortised cost

284
284

118,589
54,543

2024
2023

£000s
£000s
Trade and other payables

2,949
2,629

SILENCE THERAPEUTICS PLC

(27 Financial instruments and risk management note continued)
Credit quality of financial assets (loans and receivables)
The maximum exposure to credit risk at the reporting date by class of financial asset was:

Cash and cash equivalents and U.S. Treasury Bills are not considered to be exposed to significant credit risk due to the
fact they are held in a financial institution with an “A” rating. The Group considers the possibility of significant loss in the
event of non-performance by a financial counterparty to be unlikely.
The Group regularly monitors the creditworthiness of its customers and at the reporting date, no financial assets are
credit impaired.
Capital management
The Group considers its capital to be equal to the sum of its total equity (£106.9) million (2023: (£17.1) million). The
Group monitors its capital using a number of measures including cash flow projections, working capital ratios, the cost
to achieve pre-clinical and clinical milestones and potential revenue from existing partnerships and ongoing licensing
activities. The Group’s objective when managing its capital is to ensure it obtains sufficient funding for continuing as a
going concern. The Group funds its capital requirements through the issue of new shares to investors, milestone and
research support payments received from existing licensing partners and potential new licenses.
Interest rate risk
The nature of the Group’s activities and the basis of funding are such that the Group has significant liquid resources.
The Group uses these resources to meet the cost of future research and development activities. Consequently, it seeks
to minimize risk in the holding of its bank deposits while maintaining a reasonable rate of interest. The Group is not
financially dependent on the income earned on these resources and therefore the risk of interest rate fluctuations is not
significant to the business. Nonetheless, the Directors take steps to secure rates of interest which generate a return for
the Group.
Credit and liquidity risk
Credit risk is managed on a Group basis. Funds are deposited with financial institutions with a credit rating equivalent
to, or above, the main U.K. clearing banks. The Group’s liquid resources are invested having regard to the timing of
payments to be made in the ordinary course of the Group’s activities. All financial liabilities are payable in the short term
(between zero and three months) and the Group maintains adequate bank balances in either instant access or short-
term deposits to meet those liabilities as they fall due.
The Group only enters into collaboration agreements with large, reputable companies and the creditworthiness of
customers is monitored on an ongoing basis.
The Group applies the IFRS 9 simplified approach to measuring expected credit losses which uses a lifetime expected
loss allowance for all trade receivables. Expected loss rates are based on payment profiles of past receivables and the
aging profiles of outstanding balances at the reporting period end date. The historical loss rates are adjusted to reflect

2024
2023

£000s
£000s
Trade receivables

775
228
Non-current financial assets at amortised cost

284
284
Financial assets at amortised cost

20,744
-

21,803
512

SILENCE THERAPEUTICS PLC

(27 Financial instruments and risk management note continued)
current and forward-looking information on macroeconomic factors affecting the ability of the customer to settle the
receivables. At the year-end there were no debts that were past due or are expected to be past due. It was therefore
concluded on this basis that there were no expected credit losses for the trade receivable.
Trade receivables are written off where there is no reasonable expectation of recovery. Indicators that there is no
reasonable expectation of recovery includes, but is not limited to, a failure to engage in a repayment plan with the Group.

Currency risk
The Group operates in a global market with revenue possibly arising in a number of different currencies, principally in
US dollars, sterling or euros. The majority of the operating costs are incurred in sterling with the rest predominantly in
euros. Additionally, to a lesser extent, a number of operating costs are incurred in US dollars. The Group makes use of
forward contracts to reduce its exposure to foreign currency risk where the existence, timing and quantum of future cash
inflows can be accurately predicted.

Financial assets and liabilities denominated in euros and translated into sterling at the closing rate were:

2024
2023

£000s
£000s
Financial assets

3,729
3,254
Financial liabilities

(2,401)
(1,541)
Net financial assets/(liabilities)

1,328
1,713

Financial assets and liabilities denominated in US dollars and translated into sterling at the closing rate were:

2024
2023

£000s
£000s
Financial assets

120,178
54,664
Financial liabilities

(4,349)
(3,290)
Net financial assets/(liabilities)

115,829
51,374

The following table illustrates the sensitivity of the net result for the year and the reported financial assets of the Group
in regard to the exchange rate for sterling against the euro.
During the year sterling rose by 5% (2023: 2%) against the euro. The table shows the impact of an additional weakening
or strengthening of sterling against the euro by 20%.

If sterling
If sterling

As reported
rose 20%
fell 20%

£000s
£000s
£000s
2024

Group loss for the year

(35,242)
(31,813)
(40,386)
Euro denominated net financial liabilities

1,328
1,107
1,660
Total equity at 31 December 2024

106,883
106,662
107,215

SILENCE THERAPEUTICS PLC

(27 Financial instruments and risk management note continued)

2023
Group loss for the year

(43,267) (40,221) (47,836)
Euro denominated net financial liabilities

1,713 1,428
2,141
Total equity at 31 December 2023

17,050 16,765
17,478

The following table illustrates the sensitivity of the net result for the year and the reported financial assets of the Group
in regard to the exchange rate for sterling against the U.S. dollar.
During the year sterling rose by 5% (2022: 10% decrease) against the US dollar. The table shows the impact of an
additional weakening or strengthening of sterling against the US dollar by 20%.

28.
Notes to the cash flow statement
Changes in liabilities arising from financing activities

1 January
Cash flows from
financing
activities
Non-cash flows
31
December

2024
Repayments
New lease
liabilities
2024

£000s
£000s
£000s
£000s
Lease liabilities
272
(179)
-
93
Total liabilities from financing activities
272
(179)
-
93

29.
Related party transactions

If sterling
If sterling

As reported
rose 20%
fell 20%

£000s
£000s
£000s
2024

Group loss for the year

(35,242)
(30,685)
(42,077)
U.S. dollar denominated net financial assets

115,829
100,145
150,217
Total equity at 31 December 2024

106,883
86,854
136,926
2023

Group loss for the year

(43,267)
(42,958)
(43,730)
U.S. dollar denominated net financial assets

51,374
42,812
64,218
Total equity at 31 December 2023

17,050
8,488
29,894

SILENCE THERAPEUTICS PLC
99
We have engaged in the following transactions with our directors, executive officers or holders of more than 10% of our
outstanding share capital and their affiliates, which we refer to as our related parties.
We have no related party transactions in 2023 or 2024.
Key management are considered to be Directors of the Group. Directors’ compensation is discussed in the
Remuneration Committee Report.
30.
Post Balance Sheet Events
None.

SILENCE THERAPEUTICS PLC
100
31.
Group companies
In accordance with Section 409 of the Companies Act 2006, a full list of subsidiaries, the address of the registered
offices and effective percentages of equity owned as at 31 December 2024 are disclosed below.
All subsidiaries are wholly owned.
Name
Registered office address
Place of
incorporation
and operation
Principal
technology
area
Proportion of
ownership
interest
Silence Therapeutics GmbH
Robert-Rössle-Strasse 10, 13125 Berlin, Germany
Germany
RNA
therapeutics
100%
Silence Therapeutics (London) Ltd
27 Eastcastle Street, London, W1W 8DH
England
Dormant
100%
Innopeg Ltd
27 Eastcastle Street, London, W1W 8DH
England
Dormant
100%
Silence Therapeutics Inc.
0c/o Harvard Business Services Inc., 16192
Coastal Hwy, Lewes, DE 19958
USA
RNA
therapeutics
100%
Name
Exempt from
Audit*
Exempt from
filing financial
statements
Silence Therapeutics GmbH
No
No
Silence Therapeutics (London) Ltd
Yes*
No
Innopeg Ltd
Yes*
No
Silence Therapeutics Inc.
Yes*
No
*We have taken an exemption from audit under Section 479 of the Companies Act 2006.

SILENCE THERAPEUTICS PLC
101
Company balance sheet
at 31 December 2024
Note
2024
2023
£000s
£000s
Non-current assets
Property, plant and equipment
C.5
160
360
Other intangible assets
C.5
249
284
Other long term assets
C.9
2,580
2,580
Investment in subsidiaries
C.6
18,360
18,082
Financial assets at amortised cost
C.8
284
284
21,633
21,590
Current assets
Cash and cash equivalents
C.7
96,363
53,456
Financial assets at amortised cost – term deposit
C.8
20,744
-
R&D tax credit receivable
19,461
17,627
Other current assets
C.9
11,382
8,895
Trade and other receivables
C.10
9,771
6,212
157,721
86,190
Non-current liabilities
Lease liability
C.12
-
(93)
Contract liabilities
C.13
(41,313)
(58,910)
(41,313)
(59,003)
Current liabilities
Contract liabilities
C.13
(244)
(5,161)
Trade and other payables
C.11
(30,758)
(24,792)
Lease liability
C.12
(93)
(179)
(31,095)
(30,132)
Total assets less liabilities
106,946
18,645
Net assets
106,946
18,645
Capital and reserves attributable to the owners of the parent
Share capital
7,083
5,942
Capital reserves
C.14
435,340
313,585
Accumulated losses
(335,477)
(300,882)
Total equity
106,946
18,645
The Company made a loss of £37.1 million in the year ended 31 December 2024 (2023: £40.5 million).
The financial statements on pages 101 to 113 were approved by the Board on 29 April 2025 and signed on its behalf.
Craig Tooman
Chief Executive Officer
Company number: 02992058
The accompanying accounting policies and notes form an integral part of these financial statements.

SILENCE THERAPEUTICS PLC

102

Company statement of changes in equity
year ended 31 December 2024

Note
Share
capital
Capital
reserves
Accumulated
losses
Total
equity

£000s
£000s
£000s
£000s
At 1 January 2023
5,390
277,676
(261,572)
21,494
Recognition of share-based payments
-
13,050
-
13,050
Options exercised in the year
-
(1,918)
1,918
-
Proceeds from shares issued
552
24,777
-
25,329
Transactions with owners recognised directly in equity
552
35,909
1,918
38,379
Loss for the year
-
-
(41,228)
(41,228)
At 31 December 2023
5,942
313,585
(300,882)
18,645
Recognition of share-based payments
C.14
-
12,754
-
12,754
Options exercised in the year
C.14
-
(2,470)
2,470
-
Proceeds from shares issued
C.14
1,141
111,471
-
112,612
Transactions with owners recognised directly in equity
1,141
121,755
2,470
125,366
Loss for the financial year
-
-
(37,065)
(37,065)
At 31 December 2024
7,083
435,340
(335,477)
106,946

The accompanying accounting policies and notes form an integral part of these financial statements.

SILENCE THERAPEUTICS PLC

103

Notes to the financial statements
Year ended 31 December 2024

C.1
General information

Silence Therapeutics plc (‘the Company’) is primarily involved in the discovery, delivery and development of RNA
therapeutics. Silence Therapeutics plc, is a public Company limited by shares registered in England and Wales, with
company number 02992058. The Company’s registered office is 27 Eastcastle Street, London, W1W 8DH.

C.2
Basis of preparation

These financial statements are prepared in accordance with Financial Reporting Standard 101 ‘Reduced Disclosure
Framework’. This applies the recognition, measurement and presentation requirements of international accounting
standards in conformity with the requirements of the Companies Act 2006, but it makes amendments where necessary
in order to comply with the Act and take advantage of the FRS 101 disclosure exemptions.
As permitted by FRS 101, the Company has taken advantage of the disclosure exemptions in relation to:

the requirements of paragraphs 45(b) and 46-52 of IFRS 2 Share based Payment;

the requirements of IFRS 7 Financial Instruments: Disclosures;

the requirements of paragraphs 91-99 of IFRS 13 Fair Value Measurement;

the requirement in paragraph 38 of IAS 1 ‘Presentation of Financial Statements’ to present comparative
information in respect of: (i) paragraph 79(a) (iv) of IAS 1, (ii) paragraph 73(e) of IAS 16 Property Plant
and Equipment (iii) paragraph 118 (e) of IAS 38 Intangibles Assets;

the requirements of paragraphs 10(d), 10(f), 16, 38A to 38D, 39 to 40 ,111 and 134-136 of IAS 1
Presentation of Financial Statements;

the requirements of IAS 7 Statement of Cash Flows;

the requirements of paragraphs 30 and 31 of IAS 8 Accounting Policies, Changes in Accounting
Estimates and Errors;

the requirements of paragraph 17 of IAS 24 Related Party Disclosures;

the requirements in IAS 24 Related Party Disclosures to disclose related party transactions entered into
between two or more members of a group
The financial statements have been prepared under the historical cost convention and on the going concern basis
(see note 2 in the consolidated financial statements). The financial statements are prepared in sterling, which is
also the functional currency of the Company, and presented to the nearest thousand pounds.
The principal accounting policies, which have been applied consistently, are as set out in note 2 of the
consolidated financial statements except those that are Company specific and noted below.

SILENCE THERAPEUTICS PLC

104

Going Concern

The Company has incurred recurring losses since inception, including net losses of £37.1 million for the year ended 31
December 2024. As of 31 December 2024, the Company had accumulated losses of £335.5 million.
The Company expects to incur operating losses for the foreseeable future as it continues its research and development
efforts, seeks to obtain regulatory approval of its product candidates and pursues any future product candidates the
Company may develop.
To date, the Company has funded its operations through upfront payments and milestones from collaboration
agreements, equity offerings and proceeds from private placements, as well as management of expenses and other
financing options to support its continued operations. In 2024, the Company raised additional proceeds of £21.7million
($27.7 million) before deducting £0.7 million ($0.9 million) in placement agent fees and other expenses, from sales of
ADSs under its Sales Agreement. On 5 February 2024, the Company announced a private placement of 5,714,286 of
the Company’s American Depositary Shares (“ADSs”), each representing three ordinary shares, at a price of $21.00
per ADS, with new and existing institutional and accredited investors (the “Private Placement”). The aggregate gross
proceeds of the Private Placement was £95.4 million ($120.0 million) before deducting approximately £6.1 million ($7.7
million) in placement agent fees and other expenses. In 2024, the Company received a £7.9 million ($10.0 million)
milestone payment from the AstraZeneca Collaboration and achieved another £1.6 ($2.0 million) in milestone payments
from the Hansoh collaboration. As of 31 December 2024, the Company had cash and U.S. treasury bills of £117.1
million.
The Company believes that its current cash and cash equivalents are sufficient to fund its operating expenses for at
least the next twelve months. For this reason, the Company continues to adopt the going concern basis in preparing the
financial statements.
Investments in subsidiaries
Investments in subsidiaries comprise shares in the subsidiaries and quasi-equity loans from the Company. Investments
in shares of the subsidiaries are stated at cost less provisions for impairment in line with IAS 27 (Separate Financial
Statements).
Quasi-equity loans
Quasi-equity loans are stated at amortised cost, net of expected credit losses in line with IFRS 9 (Classification and
Measurement of Financial Instruments).
Critical accounting judgements and key sources of estimation uncertainty
In the process of applying the entity’s accounting policies, management makes estimates and judgements that have an
effect on the amounts recognised in the financial statements. Although these estimates are based on management’s
best knowledge of current events and actions, actual results may ultimately differ from those estimates.
The critical judgements concerning the future, and other key sources of estimation uncertainty at the balance sheet
date, that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within
the next financial year, are those relating to the following:

the application of IFRS 15 in determining revenue from contracts with customers specifically (Refer to note 2.18
in the notes to the consolidated financial statements):
o
the determination of the number of performance obligations (judgement);
o
the allocation of the upfront payments between the performance obligations (judgement);
o
the estimate of the future costs to be incurred;

the carrying value of the investment in subsidiary undertakings as detailed in note C.6.

SILENCE THERAPEUTICS PLC

105

C.3
Income statement
The Company has taken advantage of Section 408 of the Companies Act 2006 and has not included its own income
statement in these financial statements.

C.4
Directors and staff costs
Staff costs, including Directors’ remuneration, during the year for the Company were as follows:

2024
2023

£000s
£000s
Wages and salaries

10,142
10,247
Social security costs

683
823
Share-based payments charge

12,754
13,050
Other pension costs

438
420

24,017
24,540

Remuneration detail for all Directors is presented in the Remuneration Committee report. See page 32 for further
details. Share based payment charges are calculated based on options held by employees of the group. The expense
for non-company employees is then recharged to individual entities.

The monthly average number of employees of the Company was as follows:

2024
2023

Number
Number
Research and development and associated support services

25
26
Administration

16
16
Total average number of employees

41
42

SILENCE THERAPEUTICS PLC

106

C.5
Property, plant and equipment and intangible assets

Equipment and
furniture
Right-of-use
asset
Total

£000s
£000s
£000s
Cost

At 1 January 2023

739
499
1,238
Additions

-
-
-
Disposals

-
-
-
At 31 December 2023

739
499
1,238
At 1 January 2024

739
499
1,238
Additions

-
-
-
Disposals

(20)
-
(20)
At 31 December 2024

719
499
1,218
Accumulated depreciation

At 1 January 2023

634
41
675
Charge for the year

36
167
203
Eliminated on disposal

-
-
-
At 31 December 2023

670
208
878
At 1 January 2024

670
208
878
Charge for the year

34
166
200
Eliminated on disposal

(20)
-
(20)
At 31 December 2024

684
374
1,058
Net book value

As at 31 December 2023

69
291
360
As at 31 December 2024

35
125
160

Intangible Assets

Licenses and
Software
Total

£000s
£000s
Cost
At 1 January 2023
430
430
Additions
-
-
Disposals

-
-
At 31 December 2023
430
430
At 1 January 2024
430
430
Additions
-
-
Disposals
(46)
(46)
Translation adjustment
-
-
At 31 December 2024
384
384
Accumulated depreciation

At 1 January 2023
110
110
Charge for the year
36
36
Eliminated on disposal
-
-
At 31 December 2023
146
146

SILENCE THERAPEUTICS PLC

107

C.6
Investments in subsidiaries

Company

2024
2023

£000s
£000s
Investment in subsidiary undertakings

18,360
18,082

The investment in subsidiary undertakings is made up as follows:

Investment
at cost
Quasi-equity
loan
Impairment
provision
(Investment)
Impairment
provision
(Loan)
Net total

£000s
£000s
£000s
£000s
£000s
Shares and loans in subsidiary undertakings

At 1 January 2023
23,713
36,608
(20,360)
(22,442)
17,519
Movement in the year
-
563
-
-
563
At 31 December 2023
23,713
37,171
(20,360)
(22,442)
18,082
Movement in the year
-
278
-
-
278
At 31 December 2024
23,713
37,449
(20,360)
(22,442)
18,360

Investments at cost total of £23.7 million (2023: £23.7 million) are analysed as follows:

£23.3 million (2023: £23.3 million) relating to Silence Therapeutics GmbH.

£0.2 million (2023: £0.2 million) relating to Silence Therapeutics Inc.

The balance of the investments at cost of £0.2 million (2023: £0.2 million) relates to Innopeg Ltd (2023: £0.1
million) and Silence Therapeutics (London) Ltd (2023: £0.1 million).

Quasi-equity loans total of £37.5 million (2023: £37.2 million) are analysed as follows:

At 31 December 2024, an interest-bearing unsecured loan of £15.0 million (2023: £14.7 million) was outstanding
from Silence Therapeutics plc to Silence Therapeutics GmbH. The movement in the year includes a foreign
exchange loss of £0.6 (2023: £0.3 million) and accrued interest of £0.9 million (2023: £0.9 million).

At 31 December 2024, a non-interest-bearing unsecured loan of £22.4 million (2023: £22.4 million) was
outstanding from Silence Therapeutics plc to Silence Therapeutics (London) Ltd. This quasi-equity loan has
been fully provided for.
At 1 January 2024
146
146
Charge for the year
35
35
Eliminated on disposal
(46)
(46)
At 31 December 2024
135
135
Net book value
As at 31 December 2023
284
284
As at 31 December 2024
249
249

SILENCE THERAPEUTICS PLC

108

(C.6 Investment in subsidiaries note continued)
Impairment provision totalling £42.8 million (2023: £42.8 million) is analysed as follows:

£20.2 million (2023: £20.2 million) relating to Silence Therapeutics GmbH. In accordance with IAS 36
Impairment of Assets, the carrying value of the net investment in Silence Therapeutics GmbH of £3.1 million
(2023: £3.1 million) has been assessed by comparing its carrying value to its recoverable amount. The
recoverable amount is based on value in use. A discounted cash flow model has been used to make this
assessment and management determined that there was no impairment. The model is prepared based on a 10
year forecast which management consider to be an accurate measure of further cash flows. The discount rate
used was 14.7% and resulting headroom was £6.3 million. Management has assessed that, if no additional
milestones were to be achieved for the first target of our AstraZeneca Collaboration, this would result a reduction
the headroom by of £3.8 million.

£0.2 million (2023: £0.2 million) relating to the investments held in Silence Therapeutics (London) Ltd and
Innopeg Ltd and they are not deemed to be recoverable.

Silence Therapeutics plc has recorded an impairment provision against the quasi-equity loans of £22.4 million
in Silence Therapeutics (London) Ltd and Innopeg Ltd (2023: £22.4 million) as they are not deemed to be
recoverable.

In considering the recoverability of the loan with Silence Therapeutics GmbH, management have calculated the
expected credit loss using the 3 stage model methodology under IFRS 9 and recognised a lifetime credit loss.
Management assess credit loss as the present value of the difference between: a) the contractual cash flows
that are due to an entity under the contract; and b) the cash flows that the entity expects to receive. As a result
of this, management has determined that a provision of £30 thousand is required (2023: £30 thousand). In their
assessment, management have netted the intercompany trading balances against this loan receivable as
allowed under the loan contract.

Subsidiary companies
The principal activity of all subsidiaries is the research and development of pharmaceutical products. All subsidiary
companies are consolidated in the Group’s financial statements:

*We have taken an exemption from audit under Section 479 of the Companies Act 2006.
Name

Registered office address
Place of
incorporation
and operation
Principal
technology
area
Proportion of
ownership
interest

Silence Therapeutics GmbH
Robert-Rössle-Strasse 10, 13125 Berlin, Germany
Germany
RNA
therapeutics
100%
Silence Therapeutics (London) Ltd
27 Eastcastle Street, London, W1W 8DH
England
Dormant
100%
Innopeg Ltd
27 Eastcastle Street, London, W1W 8DH
England
Dormant
100%
Silence Therapeutics Inc.
16192 Coastal Highway, Lewes, DE 19958, U.S.A.
USA
RNA
therapeutics
100%
Name

Exempt from
audit
Exempt from
filing financial
statements
Silence Therapeutics GmbH

No
No
Silence Therapeutics (London) Ltd

Yes*
No
Innopeg Ltd

Yes*
No
Silence Therapeutics Inc.

Yes*
No

SILENCE THERAPEUTICS PLC

109

C.7
Cash and cash equivalents
Cash at bank comprises balances held by the company in current and short-term bank deposits with an original maturity
of three months or less. The carrying amount of these assets approximates to their fair value.

2024
2023

£000s
£000s
Cash at bank and in hand

44,719
24,418
U.S. Treasury Bills

51,644
29,038
Total Cash and cash equivalents

96,363
53,456

C.8
Financial assets at amortised cost
Non-current financial assets at amortized cost primarily relate to deposits for properties.
Current financial assets at amortized cost, other than trade receivables as disclosed in C.12, include U.S. Treasury
Bills (with maturities from purchase date over three months).

C.9
Other assets

2024
2023

£000s
£000s
Current financial assets at amortised cost – U.S. Treasury Bills

20,744
-
Financial assets at amortised cost - non-current

284
284
Total financial assets at amortised cost

21,028
284

2024
2023

£000s
£000s
Prepayments

10,273
8,033
VAT receivable

1,109
862
Total other current assets

11,382
8,895

Prepayments

Other long term assets

2,580
2,580

SILENCE THERAPEUTICS PLC

110

C.10
Trade and other receivables

2024
2023

£000s
£000s
Trade receivables

775
228
Amount receivable from subsidiary undertaking

8,996
5,984
Total trade and other receivables

9,771
6,212

The Directors consider that the carrying amount of trade receivables approximates to their fair value.

No interest is charged on outstanding receivables. There were no overdue trade receivables balances.

In considering the recoverability of the amount receivable from Silence Therapeutics GmbH, management have
calculated the expected credit loss using the 3 stage model methodology under IFRS 9 and recognised a lifetime credit
loss. Management assess credit loss as the present value of the difference between: a) the contractual cash flows that
are due to an entity under the contract; and b) the cash flows that the entity expects to receive. As a result of this,
management has determined that a provision of £0.3 million is required (2023: £0.8 million). In their assessment,
management have netted the intercompany trading balances against the loan receivable as allowed under the loan
contract.

C.11
Trade and other payables

2024
2023

£000s
£000s
Trade payables

2,783
2,770
Amount payable to subsidiary undertaking

19,764
14,176
Social security and other taxes

120
155
Accruals and other payables

8,091
7,691
Total trade and other payables

30,758
24,792

The Directors consider that the carrying amount of trade and other payables approximates to their fair value. Amounts
payable to subsidiary undertakings are interest free and unsecured.

C.12
Lease liability

2024
2023

£000s
£000s
Lease liability - current

93
179
Lease liability – non-current

-
93
Total lease liability

93
272

In 2024 the lease liability recognised on the face of the balance sheet comprises of the Group’s London office, which
was renegotiated upon completion of the original term, with the new term beginning in September 2022. The
repayment of the principal portion of these lease liabilities for the year-ending 31 December 2024 was £0.2 million
(2023: £0.2 million).

SILENCE THERAPEUTICS PLC

111

C.13
Contract liabilities
Contract liabilities comprise entirely deferred revenue in respect of the Mallinckrodt, AstraZeneca plc, and Hansoh
research collaborations.

2024
2023

£000s
£000s
Contract liabilities – current

244
5,161
Contract liabilities – non-current

41,313
58,910

41,557
64,071

C.14
Capital reserves
The capital redemption reserve was created in 2012 following the reduction of nominal share capital to 0.1p per share.
It is required under Section 733 of the Companies Act 2006, held to maintain the capital of the Company when shares
are bought back and subsequently cancelled without court approval.
Due to the size of the deficit on the accumulated losses account, the Company has no distributable reserves.
The share premium account reflects the premium to nominal value paid on issuing shares less costs related to the issue.
The merger reserve was created on issuance of shares relating to the acquisition of Silence Therapeutics GmbH.

Share
premium
account
Merger
reserve
Share-based
payment reserve
Capital
redemption
reserve
Total

£000s
£000s
£000s
£000s
£000s
At 1 January 2023
226,670
22,064

23,748
5,194
277,676
Shares issued
25,411
-

-
-
25,411
On options in issue during the year
-
-

13,050
-
13,050
On options exercised during the year
381
-

(1,918)
-
(1,537)
Costs capitalised in respect of issuance of shares during the
period.
(1,015)
-

-
-
(1,015)
Movement in the year
24,777
-

11,132
-
35,909
At 31 December 2023
251,447
22,064

34,880
5,194
313,585
Shares issued
115,995
-

-
-
115,995
On options in issue during the year
-
-

12,754
-
12,754
On options exercised during the year
2,344
-

(2,470)
-
(126)
Costs capitalised in respect of issuance of shares during the
period.
(6,868)
-

-
-
(6,868)
Movement in the year
111,471
-

10,284
-
121,755
At 31 December 2024
362,918
22,064

45,164
5,194
435,340

SILENCE THERAPEUTICS PLC

112

C.15
Current tax receivable
Estimated tax losses of £131.5 million (2023: £129.7 million) are available for relief against future profits.
The deferred tax asset not recognized in these financial statements on the estimated losses and the treatment of the
equity settled share- based payments, net of any other temporary differences is detailed below. During the year the
Group has accrued £19.4 million in research and development tax credits, £10.7 million relates to 2024 and £8.7 million
is the 2023 research and development tax credit which the Group has not yet received. (2023: £7.8 million). Research
and development tax credit in respect of the current year includes amounts for unfunded projects that are permissible
to claim under the Small or Medium Enterprise ('SME') R&D tax scheme.
The corporation tax main rate during 2024 was 25% (2023: 25%). The amount of tax credit for 2024 includes the impact
of the changes in credit rates enacted as part of Finance Act 2024. Amendments to the U.K. R&D tax credit regime
included in Finance Act 2024, which was enacted in February 2024, increased the cash rebate that may be claimed
from such date to 26.97% of qualifying expenditure, if we qualify as “R&D intensive” for an accounting period (broadly,
a loss making SME whose relevant R&D expenditure represents 40% for accounting periods beginning on or after 1
April 2023, or 30% for accounting periods beginning on or after 1 April 2024, of its total expenditure for that accounting
period).
Since the Group does not have an establishment or place of business in China, the Group is subject to withholding tax
on gross income from dividends, interest, lease of property, royalties, and other China-source passive income. In 2021
the Group entered into a collaboration agreement with Hansoh, a biopharmaceutical company in China and received a
£11.9 million ($16 million) upfront payment, which required withholding tax of £1.6 million ($2 million). In 2023 the Group
received a milestone payment of £3.2 million ($4.0 million), which required withholding tax of £0.4 million. In 2024 the
Group received a milestone payment of £1.6 million ($2.0 million), which required withholding tax of £0.2 million.
The Group has the following unrecognised deferred tax assets as at 31 December 2024:

2024
2023

Gross
Gross

£000s
£000s
Trading losses

131,487
129,672
Share based payments

730
7,679
Capital losses

7,873
7,873
Total unrecognised deferred tax asset

140,090
145,224

Total unrecognised deferred tax assets are calculated based on the main corporate tax rate of 25% (25% for 2023) as
this is the rate applicable to when we expect to utilise these deferred tax assets. Unrecognised deferred tax assets
from foreign trading losses are calculated at the tax rate applicable to the related jurisdiction.

Deferred tax assets are recognised where it is probable that future taxable profit will be available to utilise losses. Due
to the uncertainty of future capital gains, a deferred tax asset in respect of capital losses was not recognised at 31
December 2024 (2023: nil).

C.16
Related party transactions

We have no related party transactions in 2023 or 2024.

SILENCE THERAPEUTICS PLC

113

C.17
Post balance sheet events

None.

SILENCE THERAPEUTICS PLC

114

Company Information and Advisers
Secretary
Rhonda Hellums
Registered Office
27 Eastcastle Street
London W1W 8DH,
United Kingdom
Registered Number
02992058
Registrar
Link Asset Services
65 Gresham Street
London EC2V 7NQ,
United Kingdom
Independent Auditors
PricewaterhouseCoopers LLP
Chartered Accountants and Statutory Auditors
3 Forbury Place
23 Forbury Road
Reading
Berkshire RG1 3JH
United Kingdom
Legal Adviser
Cooley (UK) LLP
22 Bishopsgate
London EC2N 4BQ
United Kingdom
Silence Trademarks
Silence
Silence Therapeutics
The Silence Therapeutics logo
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SILENCE THERAPEUTICS PLC

115

Silence Therapeutics plc

United Kingdom
72 Hammersmith Road
London, W14 8TH
+44(0)20 3457 6900

Germany
Robert-Rossle-Str.10
D-13125 Berlin
+49 30 9489 2800

United States
221 River Street
9th Floor
Hoboken, NJ 07030