Pozelimab Gets Priority Review for CHAPLE, a Rare Hereditary Immune Disease

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CHAPLE disease is a rare genetic disorder caused by mutations in the CD55 gene.

The Food and Drug Administration (FDA) has accepted for Priority Review the Biologics License Application (BLA) for pozelimab for the treatment of patients 1 year of age and older with CHAPLE disease.

CHAPLE disease (also known as CD55 deficiency with hyperactivation of complement, angiopathic thrombosis and protein losing enteropathy or CD55-deficient protein-losing enteropathy) is a rare immune disease caused by mutations in the CD55 gene resulting in overactivation of the complement system. The disease typically starts at infancy and is characterized by abdominal pain, bloody diarrhea, vomiting, malnutrition, slow growth, edema, recurrent infections, and blood clots.

Pozelimab is a monoclonal antibody designed to block complement factor C5, a protein involved in complement system activation. The BLA is supported by data from an open-label phase 2/3 trial (ClinicalTrials.gov Identifier: NCT04209634), which evaluated the efficacy and safety of pozelimab in 10 patients 1 year of age and older with CHAPLE disease. Patients received a single loading dose of pozelimab 30mg/kg intravenously on day 1, followed by weight-based doses subcutaneously weekly.

Results at 24 weeks showed all of the patients achieved rapid and sustained normalization of serum album and improvement or no worsening of clinical symptoms (eg, abdominal pain, number of bowel movements per day, and investigator-assessed facial and peripheral edema). Pozelimab was also associated with clinically meaningful increases in body weight and stature for age, as well as reductions in hospitalization days and total number of albumin transfusions. The most common adverse events reported were iron deficiency, pyrexia, rhinitis, urticaria, and vomiting.

A Prescription Drug User Fee Act target date of August 20, 2023 has been set for the application.


Pozelimab (C5 antibody) BLA for treatment of children and adults with ultra-rare CHAPLE disease accepted for FDA Priority Review. News release. Regeneron Pharmaceuticals, Inc. Accessed February 21, 2023. https://www.globenewswire.com/news-release/2023/02/21/2611922/0/en/Pozelimab-C5-Antibody-BLA-for-Treatment-of-Children-and-Adults-with-Ultra-rare-CHAPLE-Disease-Accepted-for-FDA-Priority-Review.html.