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# X4 Pharma Gains Xolremdi Approval
- URL: https://www.fdaweb.com/x4-pharma-gains-xolremdi-approval/
- Published: 2024-04-29T12:00:00.000Z
- Updated: 2026-09-14T14:29:27.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5156874

FDA has approved an X4 Pharmaceuticals NDA for Xolremdi (mavorixafor) and its use in patients 12 years of age and older with WHIM syndrome (warts, hypogammaglobulinemia, infections and myelokathexis) to increase the number of circulating mature neutrophils and lymphocytes. The rare genetic disease syndrome causes the body’s immune system to not function properly, an FDA [release](https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-first-drug-whim-syndrome-rare-disorder-can-lead-recurrent-life-threatening-infections?utm%5Fmedium=email&utm%5Fsource=govdelivery) says. “WHIM syndrome reduces the number of mature neutrophils and lymphocytes (types of white blood cells important in fighting infection) circulating within the body,” it says, adding that this causes recurrent infections, including pneumonia, sinusitis, and skin infections.

Approval was based on data from a 52-week placebo-controlled trial that enrolled 31 adolescents and adults with WHIM syndrome ([NCT03995108](https://www.accessdata.fda.gov/drugsatfda%5Fdocs/label/2024/218709s000lbl.pdf?ref=fdaweb.com)). “Xolremdi improved absolute neutrophil counts and absolute lymphocyte counts, assessed over a 24-hour period four times throughout the study,” the agency says. The average time over 24 hours that counts were above levels associated associated with an increased risk of infections was significantly longer with Xolremdi compared to the placebo group (15.0 hours compared to 2.8 hours for absolute neutrophil counts; 15.8 hours compared to 4.6 hours for absolute lymphocyte counts), it adds.