Chronic Neutropenia


  • Neutropenia is a complex disease, marked by having a low number of neutrophils, a type of white blood cell. The lower the neutrophil count, the greater the risk of infection.
  • Neutropenia can be described as chronic, congenital (from birth), or cyclical neutropenia. Not all specialists describe neutropenia the same way and not all describe it as a type of primary immunodeficiency.
    • Congenital neutropenia is both a rare blood disorder and a rare type of primary immunodeficiency (PID).
  • People living with neutropenia have few treatment options. More treatment options are needed.
  • X4 Pharmaceuticals is conducting a Phase 1b clinical trial to help researchers answer questions about the study drug, mavorixafor, and what impact it may have on people with chronic neutropenic disorders, including idiopathic, cyclic, and congenital neutropenia.

Chronic Neutropenia Voices: Kevin’s Story

Chronic Neutropenia Voices: Vanessa’s Story

Learn More:

  • –listing for the X4 study (NCT Identifier: 04154488)
  • IDYourPID—sponsored by X4 Pharmaceuticals, this website includes information about genetic testing and primary immunodeficiencies, including neutropenia.
  • National Neutropenia Network—promotes awareness, education, and research about neutropenia and provides a support system for patients and families.

X4 Pharmaceuticals does not review or control the content on the website to which this hyperlink connects and this hyperlink does not constitute an endorsement by X4 Pharmaceuticals of the content of any non-X4 Pharmaceuticals website.