Cold agglutinin disease destroys red cells through classical complement activation, and patients had no approved therapy, relying on transfusion and cold avoidance. Enjaymo (sutimlimab) was the first.
Sutimlimab selectively inhibits complement protein C1s, shutting down the classical pathway while leaving the alternative and lectin pathways intact. Given intravenously every two weeks after loading doses, it decreases the need for red blood cell transfusion due to hemolysis in adults with cold agglutinin disease.
Enjaymo holds orphan designation with no biosimilar competition and remains the only approved therapy in the indication. Its selective classical-pathway mechanism, which preserves other complement defenses, is the feature distinguishing it from broader complement inhibitors.
