Treatment patterns and overall survival of patients with double-class and triple-class refractory multiple myeloma: a US electronic health record database study.

Patients with relapsed/refractory multiple myeloma (RRMM) resistant to multiple drug classes remain a high unmet need population. This longitudinal retrospective cohort study assessed real-world treatment patterns and outcomes in adults with RRMM. Patients who had three or more prior lines of therapy including a proteasome inhibitor (PI) and an immunomodulatory agent (double-exposed) were further categorized as refractory to a PI and an immunomodulatory agent (double-class refractory,  = 381) or additionally to an anti-CD38 monoclonal antibody (triple-class refractory,  = 173). Treatment options are limited for patients with double-class or triple-class refractory disease. Retreatment is a part of standard of care. Bortezomib and lenalidomide had the highest retreatment rates among double-class and triple-class refractory patients. Survival outcomes remain poor among RRMM patients with median overall survival (OS) of 22.3 and 11.6 months for double-class refractory and triple-class refractory patients, respectively. This study highlights the need for novel efficacious therapies in this heavily pretreated RRMM population.