Mavorixafor (X4P-001) is in clinical development for the treatment of WHIM syndrome in patients aged 12 years and above. WHIM stands for warts (skin growths), hypogammaglobulinemia (low level of antibodies), infections and myelokathexis (a condition where immune cells are trapped in the bone marrow preventing them from fighting infections). Patients with WHIM syndrome have mutations (changes) in the gene for the CXCR4 receptor, which plays a role in the movement of blood cells into and from the bone marrow. Because of these mutations, the CXCR4 receptor is hyperactive and, as a consequence, blood cells (particularly neutrophils) are retained in the bone marrow, leading to low levels of neutrophils in the blood. There are no licenced therapies to treat WHIM syndrome.
Mavorixafor is an oral drug expected to reduce the activity of the CXCR4 receptor and allow neutrophils to be released from the bone marrow into the blood stream, thereby helping the body to fight infections. If licenced, mavorixafor would provide the first targeted treatment option for WHIM syndrome in patients aged 12 years and above, whose care is currently limited to the treatment of the different symptoms of WHIM syndrome.
Anifrolumab is a drug designed to specifically block type I IFN signalling by binding to part of the type I IFN receptor and therefore preventing activity of all IFNs that are involved in the inflammatory pathway. If licensed, anifrolumab will offer an add-on treatment option for patients with moderately to severely active SLE.