In a post-trial observational study, several patients with cold agglutinin disease (CAD) who had responded to sutimlimab demonstrated hematologic remission after discontinuation of treatment. This report was reported in Blood Advances.

The authors hypothesized that undetectable IgM autoantibodies among patients treated with sutimlimab may predict sustained hematologic response after treatment discontinuation.

The 3 patients included in this study were observed between 2021 and 2022. All patients had received sutimlimab as part of a named patient program and were transitioned to an open-label extension of a phase 1b study. Patients were treated with sutimlimab for approximately 3 years, then treatment was discontinued. Increased follow-up was performed in anticipation of relapsed hemolysis.

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At the start of the observational study, the 3 patients were female and aged 72 to 78. Patients had received sutimlimab for 34 to 39 months. There were 2 patients who were negative for IgM and IgG in the direct antiglobulin test with a titer of 256 for cold agglutinin.

During treatment with sutimlimab, the patients who had tested negative for IgM demonstrated normal or near normal levels of hemoglobin with resolution of hemolysis. The third patient demonstrated a less robust response.

During the 12-month follow-up after discontinuation of sutimlimab, the patients who tested negative for IgM continued to demonstrate stable hemoglobin levels with no signs of hemolysis. However, the third patient relapsed at 7 weeks after sutimlimab discontinuation with severe transfusion-dependent hemolysis.

“This is the first clinical evidence of sustained hematologic remission in some patients with CAD following discontinuation of anti-C1s treatment,” the authors concluded.

Disclosures: This research was supported by Sanofi. One of the study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of disclosures.


Gelbenegger G, Jger U, Fillitz M, et al. Sustained hematologic remission after discontinuation of sutimlimab treatment in patients with cold agglutinin disease. Blood Adv. 2023;7:1987-1990. doi: 10.1182/bloodadvances.2022008574