Cost‐effectiveness of sutimlimab in cold agglutinin disease

Abstract

Primary cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia caused by cold‐reactive antibodies that bind to red blood cells and lead to complement‐mediated hemolysis. Patients with primary CAD experience the burden of increased health resource utilization and reduced quality of life. The standard‐of‐care (SOC) in patients with primary CAD has included cold avoidance, transfusion support, and chemoimmunotherapy. The use of sutimlimab, a humanized monoclonal antibody that selectively inhibits C1‐mediated hemolysis, was shown to reduce transfusion‐dependence and improve quality of life across two pivotal phase 3 studies, further supported by 2‐year extension data. Using data from the transfusion‐dependent patient population that led to sutimlimab's initial FDA approval, we performed the first‐ever cost‐effectiveness analysis in primary CAD. The projected incremental cost‐effectiveness ratio (ICER) in our Markov model was $2 340 000/QALY, significantly above an upper‐end conventional US willingness‐to‐pay threshold of $150 000/QALY. These results are consistent across scenarios of higher body weight and a pan‐refractory SOC patient phenotype (i.e., treated sequentially with bendamustine‐rituximab, bortezomib, ibrutinib, and eculizumab). No parameter variations in deterministic sensitivity analyses changed our conclusion. In probabilistic sensitivity analysis, SOC was favored over sutimlimab in 100% of 10 000 iterations. Exploratory threshold analyses showed that significant price reduction (>80%) or time‐limited treatment (<18 months) followed by lifelong clinical remission off sutimlimab would allow sutimlimab to become cost‐effective. The impact of sutimlimab on health system costs with longer term follow‐up data merits future study and consideration through a distributional cost‐effectiveness framework.