X4 Pharmaceuticals Inc is a late-stage clinical biopharmaceutical company engaged in the research and development of novel therapeutics for the treatment of rare diseases and those with limited treatment options, with a focus on conditions resulting from dysfunction of the immune system. The Company's lead clinical candidate is mavorixafor, a small molecule antagonist of the chemokine receptor CXCR4 that is being developed as an oral, once-daily therapy. It has the ability to increase the mobilization of mature, functional white blood cells from the bone marrow into the bloodstream. It also has two pre-clinical candidates X4P-003 and X4P-002 which are CXCR4 antagonists with different properties.