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# X4 Pharma Fast Track Status for Mavorixafor
- URL: https://www.fdaweb.com/x4-pharma-fast-track-status-for-mavorixafor/
- Published: 2020-10-08T12:00:00.000Z
- Updated: 2026-09-14T16:31:53.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5147833

FDA has granted X4 Pharmaceuticals a Fast Track Designation for mavorixafor for treating adult patients with WHIM (Warts, Hypogammaglobulinemia Infections and Myelokathexis) syndrome, an inherited, primary immunodeficiency disease caused by genetic mutations in the CXCR4 receptor gene. The company describes mavorixafor as a small molecule antagonist of chemokine receptor CXCR4, currently being investigated in a Phase 3 clinical trial, [4WHIM](https://www.globenewswire.com/Tracker?data=KSUtX8gAckt68TS1Sy3FR1REY7FqFml4AFKZPhlhU9HAD5sgIu1vlABLJhjJuV%5Fa&ref=fdaweb.com). The study is expected to enroll up to 28 subjects in about 20 countries, followed by an open-label extension trial, with results expected in 2022\. “We recently showed the potential therapeutic benefit of mavorixafor in a Phase 2 clinical trial in WHIM, with significant increases in white blood cell counts and reductions in infection rates and wart burden,” it says.