X4 is a late-stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutics for the treatment of rare diseases. X4’s pipeline is comprised of a first-in-class, oral, small molecule antagonist of chemokine receptor CXCR4, which has the potential to treat a broad range of rare diseases resulting from dysfunction of the CXCR4 receptor pathway, including primary immunodeficiencies, neutropenia, and certain cancers.