FDA Issues CRL for Potential Cold Agglutinin Disease Treatment

The US Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL), prior to approving an application for sutimlimab, an investigational monoclonal antibody treatment for hemolysis in adults with cold agglutinin disease (CAD).

The letter asks Sanofi to address some deficiencies found in a pre-license inspection of a third-party manufacturing facility.

However, there were no clinical or safety deficiencies found in the Biologics License Application (BLA).

If eventually approved, sutimlimab would be the first and only approved treatment for this patient population.

Cold agglutinin disease is a chronic autoimmune hemolytic anemia disorder that causes the body’s immune system to mistakenly attack healthy red blood cells, causing the previously healthy red blood cells to rupture. This patient population could also experience chronic anemia, profound fatigue, acute hemolytic crisis, and other potential complications, including an increased risk of thromboembolic events and premature death. There are approximately 5000 CAD patients in the US.

Previously, researchers from Sanofi presented data from part A (n = 24) of an open label, single arm phase 3 study called the CARDINAL study. The trial met the primary composite efficacy endpoint defined as the proportion of CAD patients who demonstrated an increase from baseline in Hgb level ≥2 g/dL or normalization of Hgb level ≥12 g/dL at the treatment assessment time point (mean value from weeks 23, 25, and 26) and no blood transfusion from week 5-26.

Sutimlimab also met secondary endpoints by indicating improvements in disease process, including improvements in hemoglobin, normalization of bilirubin, and improvements in Functional Assessment of Chronic Illness Therapy-Fatigue Score.

“People living with cold agglutinin disease currently have no approved treatment option and experience chronic anemia and profound fatigue, which have a persistent and serious impact on their lives,” John Reed, MD, PhD, Global Head of Research and Development at Sanofi, said in a statement.