Cellectar Biosciences says CLOVER WaM study met its primary endpoint

Cellectar Biosciences announced data from its CLOVER WaM pivotal study, evaluating iopofosine I 131, a potential first-in-class, targeted radiotherapy candidate for the treatment of relapsed/refractory Waldenstrom’s macroglobulinemia patients that have received at least two prior lines of therapy, including Bruton tyrosine kinase inhibitors. CLOVER WaM is the largest study to date in relapsed or refractory WM patients post-BTKi therapy and represents the most refractory population ever tested in clinical studies based upon a review of published literature. The CLOVER WaM study met its primary endpoint with a major response rate of 61%. The overall response rate in evaluable patients was 75.6%, and 100% of patients experienced disease control. Responses were durable, with median duration of response not reached and 76% of patients remaining progression free at a median follow-up of eight months. These outcomes exceed real world data, which demonstrate a 4-12% MRR and a duration of response of approximately six months or less despite continuous treatment in a patient population that is less pretreated and less refractory to multiple classes of drugs. Notably, iopofosine monotherapy achieved an 8% stringent complete remission in this highly refractory WM population.