WHIM Syndrome


  • WHIM syndrome is a rare and difficult-to-diagnose primary immunodeficiency in which the body’s immune system does not function properly and has trouble fighting infections. Some doctors also call primary immunodeficiencies inborn errors of immunity, which are genetic mutations that cause immunodeficiencies.
  • WHIM syndrome is caused by mutations in the CXCR4 gene that cause white blood cells to get trapped in the bone marrow.
  • WHIM syndrome was named after four symptoms that most diagnosed patients have experienced: Warts, Hypogammaglobulinemia, Infections, Myelokathexis.
  • There are no existing treatments that specifically target the underlying causes of WHIM syndrome—new treatments are needed.
  • X4 Pharmaceuticals is conducting a Phase 3 clinical trial to help researchers learn if the investigational oral drug, mavorixafor, can help people with WHIM syndrome by targeting the way the disease works and if it can safely reduce bacterial infections and warts. This clinical trial is full and is not enrolling new participants.

Learn More: 

  • ClinicalTrials.gov –listing for the X4 study (NCT Identifier: 03995108) contains study sites and contact information
  • WHIMSyndrome.com—learn more about WHIM syndrome and find links to patient advocacy organizations on this site, sponsored by X4 Pharmaceuticals
  • Video—an illustrated video that shows how mavorixafor may work for people with WHIM syndrome

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