X4 Pharmaceuticals Announces FDA Approval of XOLREMDI (mavorixafor) Capsules, First Drug Indicated in Patients with WHIM Syndrome

XOLREMDI targets CXCR4 pathway dysfunction, the underlying cause of WHIM syndrome

Breakthrough Therapy approval follows Priority Review of 4WHIM Phase 3 clinical trial data

X4 granted Rare Pediatric Disease Priority Review Voucher (PRV) concurrent with approval

Conference call and webcast to be hosted today at 8:30 am ET

BOSTON, April 29, 2024 (GLOBE NEWSWIRE) -- X4 Pharmaceuticals (Nasdaq: XFOR), a company driven to improve the lives of people with rare diseases of the immune system, today announced that the U.S. Food and Drug Administration (FDA) has approved XOLREMDI (mavorixafor) capsules for 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.

XOLREMDI, a selective CXC chemokine receptor 4 (CXCR4) antagonist, is the first therapy specifically indicated in patients with WHIM syndrome, a rare, combined primary immunodeficiency and chronic neutropenic disorder caused by CXCR4 pathway dysfunction. People with WHIM syndrome characteristically have low blood levels of neutrophils (neutropenia) and lymphocytes (lymphopenia) and experience serious and/or frequent infections. The FDA granted Breakthrough Therapy Designation to mavorixafor in WHIM syndrome and evaluated the New Drug Application (NDA) under Priority Review, a designation for therapies that have the potential to provide significant improvement in the treatment, diagnosis, or prevention of serious conditions.

“The approval of XOLREMDI is a transformational milestone both for X4 and, more importantly, for the WHIM syndrome community,” said Paula Ragan, Ph.D., President and Chief Executive Officer of X4 Pharmaceuticals. “We are incredibly grateful to the people living with WHIM syndrome, their families, and the investigators who took part in our clinical program, to U.S. regulators for their continued focus on rare-disease treatment development, and to our dedicated employees for making this targeted breakthrough therapy a reality.”

“Effective and innovative treatments are critical for those diagnosed with a primary immunodeficiency. The approval of XOLREMDI marks an important advancement for people living with WHIM syndrome, who are susceptible to serious and frequent infections,” said Jorey Berry, President and Chief Executive Officer of the Immune Deficiency Foundation (IDF). “We are very pleased to have been a partner to X4 in their journey to bring this much-needed treatment to this underserved rare disease community.”