X4 Pharma wins FDA nod to treat rare immunodeficiency disease

April 29, 2024

The U.S. FDA has approved X4 Pharmaceuticals' selective CXCR4 antagonist, branded Xolremdi, for patients 12 years and older with a rare genetic immunodeficiency disease known as WHIM syndrome.

Xolremdi is the first therapy specifically indicated for patients with WHIM (warts, hypogammaglobulinemia, infections and myelokathexis), a combined primary immunodeficiency and chronic neutropenic disorder caused by CXC chemokine receptor 4  pathway dysfunction.

People with WHIM syndrome have low blood levels of certain white blood cells, known as neutrophils and lymphocytes, and experience frequent infections. Xolremdi capsules are designed to address dysregulated CXCR4 pathway signaling, elevating absolute neutrophil and lymphocyte counts, increasing patients’ ability to fight infections.

With the FDA approval, X4 has received a Rare Pediatric Disease Priority Review Voucher.

The approval marks the first commercialized product for Boston-based X4. The company says it is exploring the use of Xolremdi in additional patient populations, including those with certain chronic neutropenic disorders.