The Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL) to Sanofi regarding the Biologics License Application (BLA) for sutimlimab for the treatment of hemolysis in adults with cold agglutinin disease.

Sutimlimab is an investigational monoclonal antibody designed to stop hemolysis by selectively inhibiting C1s in the classical complement pathway. The BLA submission included data from part A of the open-label, single-arm pivotal phase 3 CARDINAL study that evaluated the efficacy and safety of sutimlimab in 24 patients with primary cold agglutinin disease who had a recent blood transfusion. 

While there were no clinical or safety issues noted in the submission, the FDA issued the CRL due to deficiencies identified during a pre-license inspection of a third-party facility responsible for manufacturing. These deficiencies will need to be resolved before a decision on the BLA can be made, according to the Agency.

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Sutimlimab was previously granted Breakthrough Therapy and Orphan Drug designations by the FDA for cold agglutinin disease.

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FDA issues Complete Response Letter for sutimlimab, an investigational treatment for hemolysis in adults with cold agglutinin disease. [press release]. Paris, France: Sanofi; November 13, 2020.