X4 Pharmaceuticals Announces EMA Validation of Marketing Authorization Application (MAA) for Mavorixafor for the Treatment of WHIM Syndrome

Company Updates - X4 Pharmaceuticals announced that its Marketing Authorization Application (MAA) for mavorixafor, a treatment for WHIM syndrome, has been validated for review by the European Medicines Agency (EMA) [1] - Mavorixafor received U S Food and Drug Administration (FDA) approval in April 2024 as XOLREMDI, an oral, once-daily treatment for patients aged 12 and older with WHIM syndrome [1] - The company expects a decision on the MAA in the first half of 2026 [1] - X4 Pharmaceuticals has an exclusive licensing and supply agreement with Norgine to commercialize mavorixafor in Europe, Australia, and New Zealand [3] Clinical Trial Results - The global, pivotal 4WHIM Phase 3 trial met its primary endpoint and a key secondary endpoint, with no treatment-related serious adverse events reported and no discontinuations for safety events [2] - Once-daily oral mavorixafor resulted in reductions in the rate, severity, and duration of infections in participants with WHIM syndrome [2] Market Opportunity - If approved by the EMA, mavorixafor would be the first drug indicated for patients with WHIM syndrome in Europe, where the population is estimated to be approximately 1,000 people [3] - In the U S, at least 1,000 people are currently diagnosed with WHIM syndrome, with another 1,000 estimated in Europe [11] Product Information - Mavorixafor is a small-molecule antagonist of the CXCR4 receptor, developed as a once-daily oral therapy for rare primary immunodeficiencies, including WHIM syndrome [2] - XOLREMDI (mavorixafor) is a selective CXCR4 receptor antagonist approved in the U S for increasing the number of circulating mature neutrophils and lymphocytes in patients with WHIM syndrome [12] Company Background - X4 Pharmaceuticals focuses on developing and commercializing innovative therapies for rare diseases of the immune system, leveraging expertise in CXCR4 and immune system biology [13] - The company is headquartered in Boston, Massachusetts, and operates a research center of excellence in Vienna, Austria [13]