The Food and Drug Administration (FDA) has granted Orphan Drug designation to X4P-001-RD for the treatment of WHIM syndrome, a primary immunodeficiency disease. WHIM is an acronym of the clinical symptoms of the syndrome: warts, hypogammaglobulinemia, infections, and myelokathexis. It is a rare disorder and the precise prevalence of incidence is unknown. 

X4 Pharmaceuticals is developing this oral, small molecule inhibitor of CXCR4, which is currently in a Phase 2/3 clinical trial. The Company reported results from the Phase 2 portion of the trial involving 42 participants that showed meaningful increases in neutrophil and lymphocyte counts with daily administration of X4P-001-RD. It was also deemed safe and well-tolerated for durations of up to 400 days.

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WHIM is caused by genetic mutations in the CXCR4 receptor gene which leave patients susceptible to certain infections. Current therapy for WHIM is limited to the treatment of acute infections with antibiotics or prevention through the use of intravenous immunoglobulin or G-CSF. “We are excited to continue to work with leaders, experts and patient advocates addressing primary immunodeficiency disease to raise awareness for WHIM diagnosis and treatment and to bring X4P-001-RD to patients suffering with this disease,” said Paula Ragan, PhD, CEO of X4.

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