X4 Pharmaceuticals, Inc., a biopharmaceutical company, focuses on the research, development, and commercialization of novel therapeutics for the treatment of rare diseases of the immune system. It offers XOLREMDI, an orally small-molecule selective antagonist of chemokine receptor CXCR4, which is in phase 3 clinical trial for the treatment of patients with warts, hypogammaglobulinemia, infections, and myelokathexis syndrome. It has a license agreement with Abbisko Therapeutics Co Ltd. to manufacture and distribute XOLREMDI in mainland China, Taiwan, Hong Kong and Macau; Norgine to develop, manufacture, and commercialize mavorixafor in Europe, Australia, and New Zealand; and Genzyme Corporation for CXCR4 receptor to develop and commercialize products containing licensed compounds for all therapeutic, prophylactic and diagnostic uses. The company is headquartered in Boston, Massachusetts.