A phase 3 randomized trial of mavorixafor, a CXCR4 antagonist, for WHIM syndrome
- PMID: 38643510
- PMCID: PMC11251404
- DOI: 10.1182/blood.2023022658
A phase 3 randomized trial of mavorixafor, a CXCR4 antagonist, for WHIM syndrome
Abstract
We investigated efficacy and safety of mavorixafor, an oral CXCR4 antagonist, in participants with warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome, a rare immunodeficiency caused by CXCR4 gain-of-function variants. This randomized (1:1), double-blind, placebo-controlled, phase 3 trial enrolled participants aged ≥12 years with WHIM syndrome and absolute neutrophil count (ANC) ≤0.4 × 103/μL. Participants received once-daily mavorixafor or placebo for 52 weeks. The primary end point was time (hours) above ANC threshold ≥0.5 × 103/μL (TATANC; over 24 hours). Secondary end points included TAT absolute lymphocyte count ≥1.0 × 103/μL (TATALC; over 24 hours); absolute changes in white blood cell (WBC), ANC, and absolute lymphocyte count (ALC) from baseline; annualized infection rate; infection duration; and total infection score (combined infection number/severity). In 31 participants (mavorixafor, n = 14; placebo, n = 17), mavorixafor least squares (LS) mean TATANC was 15.0 hours and 2.8 hours for placebo (P < .001). Mavorixafor LS mean TATALC was 15.8 hours and 4.6 hours for placebo (P < .001). Annualized infection rates were 60% lower with mavorixafor vs placebo (LS mean 1.7 vs 4.2; nominal P = .007), and total infection scores were 40% lower (7.4 [95% confidence interval [CI], 1.6-13.2] vs 12.3 [95% CI, 7.2-17.3]). Treatment with mavorixafor reduced infection frequency, severity, duration, and antibiotic use. No discontinuations occurred due to treatment-emergent adverse events (TEAEs); no related serious TEAEs were observed. Overall, mavorixafor treatment demonstrated significant increases in LS mean TATANC and TATALC, reduced infection frequency, severity/duration, and was well tolerated. The trial was registered at www.clinicaltrials.gov as #NCT03995108.
© 2024 American Society of Hematology. Published by Elsevier Inc. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.
Conflict of interest statement
Conflict-of-interest disclosure: R.B. is a consultant for X4 Pharmaceuticals, Inc, Angelini Pharma, and Janssen. L.A. has received research funding (to Institu de Recerca Sant Joan de Déu) from CSL Behring, Pharming, and Grifols and is a speaker for Novartis, Sanofi, Roche, and UCB Pharmaceuticals. A.A. has received research funding/grants from X4 Pharmaceuticals, Inc, Grifols, and Argenx; and is a consultant for Grifols, Argenx, Takeda Pharmaceuticals, Adma Biologics, Inc, and Octapharma. A.A.B. has received research funding from X4 Pharmaceuticals, Inc, and the National Institutes of Health. D.D. has consulted, received research funding from, and received honoraria from X4 Pharmaceuticals, Inc. K.E.D. is on the advisory board of Agios. H.J.K. receives research funding from Amgen and is a member on the board of directors or advisory committees for Amgen, Novartis, GPCR Therapeutics, and Cartexell. A.K. has received research funding (to Pavlov University) from X4 Pharmaceuticals, Inc, Alexion, and Apellis and is a speaker for Novartis, Generium, Sobi, AstraZeneca, and Johnson & Johnson. D.L. is a board member for RCPA. C.L. receives research grants from Emek Center Pediatric Hematology University Hospital. J.P. is on the advisory board of Allergy & Anaphylaxis Australia, Food and Allergy Standards Australia and New Zealand, and National Blood Authority and is the director of the Australasian Society of Clinical Immunology and Allergy (QPIAS). A.S. is a speaker for Sobi, Novartis, and Octapharma. T.K.T. is a consultant for X4 Pharmaceuticals, Inc and also receives research funding from X4 Pharmaceuticals, Inc, AbbVie, Inc, Viela Bio, Horizon, and Chiesi. M.G.V. has received research funding outside the current work from Austrian National Bank, a grant from Pfizer, and honoraria from Gilead, Astro Pharma, and Menarini. J.D. is a consultant for X4 Pharmaceuticals, Inc. A.B., K.C., S.D., Y.H., H.J., S.L., R.M., T.Y., and A.G.T. are current employees and/or have equity ownership in X4 Pharmaceuticals, Inc. M.S. was employed by X4 Pharmaceuticals, Inc, at the time of this work, has equity ownership in X4 Pharmaceuticals, Inc, and is a member of the board of directors of X4 Pharmaceuticals, Inc. G.J.B. is a member of the board of directors of X4 Pharmaceuticals, Inc, and has stock options in the company. The remaining authors declare no competing financial interests.
Figures




Comment in
-
Mavorixafor: a new hope for WHIM syndrome.Blood. 2024 Jul 4;144(1):1-2. doi: 10.1182/blood.2024024942. Blood. 2024. PMID: 38963672 No abstract available.
Similar articles
-
Results of a phase 2 trial of an oral CXCR4 antagonist, mavorixafor, for treatment of WHIM syndrome.Blood. 2020 Dec 24;136(26):2994-3003. doi: 10.1182/blood.2020007197. Blood. 2020. PMID: 32870250 Free PMC article. Clinical Trial.
-
Mavorixafor: a CXCR4 antagonist for WHIM syndrome.Immunopharmacol Immunotoxicol. 2025 Jun;47(3):385-391. doi: 10.1080/08923973.2025.2491551. Epub 2025 Apr 14. Immunopharmacol Immunotoxicol. 2025. PMID: 40223492 Review.
-
CXCR4 antagonism ameliorates leukocyte abnormalities in a preclinical model of WHIM syndrome.Front Immunol. 2024 Nov 11;15:1468823. doi: 10.3389/fimmu.2024.1468823. eCollection 2024. Front Immunol. 2024. PMID: 39588369 Free PMC article.
-
Genotype-phenotype correlations in WHIM syndrome: a systematic characterization of CXCR4WHIM variants.Genes Immun. 2022 Sep;23(6):196-204. doi: 10.1038/s41435-022-00181-9. Epub 2022 Sep 12. Genes Immun. 2022. PMID: 36089616 Free PMC article.
-
Unveiling WHIM syndrome: Mavorixafor's emerging role in immune restoration and therapy.Clin Exp Immunol. 2025 Jan 21;219(1):uxaf014. doi: 10.1093/cei/uxaf014. Clin Exp Immunol. 2025. PMID: 40065526 Review.
Cited by
-
Expanding CXCR4 variant landscape in WHIM syndrome: integrating clinical and functional data for variant interpretation.Front Immunol. 2024 Jul 8;15:1411141. doi: 10.3389/fimmu.2024.1411141. eCollection 2024. Front Immunol. 2024. PMID: 39040098 Free PMC article. Review.
-
Risk of Superficial Fungal Infections in WHIM Syndrome.Dermatol Ther (Heidelb). 2025 May;15(5):1173-1179. doi: 10.1007/s13555-025-01396-0. Epub 2025 Apr 3. Dermatol Ther (Heidelb). 2025. PMID: 40178760 Free PMC article.
-
Neutrophil diversity and function in health and disease.Signal Transduct Target Ther. 2024 Dec 6;9(1):343. doi: 10.1038/s41392-024-02049-y. Signal Transduct Target Ther. 2024. PMID: 39638788 Free PMC article. Review.
-
Heterogeneous phenotype of a Chinese Familial WHIM syndrome with CXCR4V340fs gain-of-function mutation.Front Immunol. 2024 Nov 7;15:1460990. doi: 10.3389/fimmu.2024.1460990. eCollection 2024. Front Immunol. 2024. PMID: 39575248 Free PMC article.
-
Targeting the chemokine receptor CXCR4 for cancer therapies.Biomark Res. 2025 May 1;13(1):68. doi: 10.1186/s40364-025-00778-y. Biomark Res. 2025. PMID: 40307933 Free PMC article. Review.
References
-
- Balabanian K, Lagane B, Pablos JL, et al. WHIM syndromes with different genetic anomalies are accounted for by impaired CXCR4 desensitization to CXCL12. Blood. 2005;105(6):2449–2457. - PubMed
-
- Hernandez PA, Gorlin RJ, Lukens JN, et al. Mutations in the chemokine receptor gene CXCR4 are associated with WHIM syndrome, a combined immunodeficiency disease. Nat Genet. 2003;34(1):70–74. - PubMed
-
- Wetzler M, Talpaz M, Kleinerman ES, et al. A new familial immunodeficiency disorder characterized by severe neutropenia, a defective marrow release mechanism, and hypogammaglobulinemia. Am J Med. 1990;89(5):663–672. - PubMed
Publication types
MeSH terms
Substances
Supplementary concepts
Associated data
LinkOut - more resources
Full Text Sources
Medical