Cellectar Updates iopofosine I 131 Clinical Trial Data

Cellectar Biosciences announced updated and mature 12-month follow-up data from its Phase 2b CLOVER WaM clinical trial evaluating iopofosine I 131 in patients with relapsed or refractory Waldenstrom macroglobulinemia. The updated dataset includes a minimum of 12 months of follow-up for all enrolled patients, as requested by the FDA, and the durability data presented here, further strengthen the previously reported efficacy results. The company also reports subset analyses from CLOVER WaM showing iopofosine I 131 demonstrated strong and consistent efficacy in both BTKi-exposed and BTKi-refractory patients. Patients enrolled in the CLOVER WaM clinical trial had a median of four prior lines of therapy, with refractory rates running from 77% in Bruton tyrosine kinase inhibitors-exposed patients to 60% in chemotherapy-exposed patients and 58% in patients exposed to both BTKi and rituximab, making this one of the most heavily pretreated and refractory WM populations studied to date. Updated 12-month data demonstrated high response rates and sustained durability, supporting its accelerated regulatory pathway and potential role as a differentiated treatment option. During the follow-up period, responses deepened and remained durable, especially considering that treatment with iopofosine I 131 is a fixed-dosed regimen containing four 30-minute infusions. Adverse events were transient and unlike other therapies approved for WM there were no significant bleeding events and low rates of infection. Cytopenias were the most common treatment-emergent adverse events. Non-hematologic toxicities were primarily low grade Iopofosine I 131 demonstrated strong and consistent efficacy in both BTKi-exposed and BTKi-refractory patients, populations that are among the most difficult to treat. These results demonstrate durability and depth of response comparable to, or exceeding, the overall study population, reinforcing the consistency of iopofosine's activity across treatment-resistant subgroups. Furthermore, comparative assessments with published datasets suggest that iopofosine I 131 delivers superior efficacy across key endpoints relative to currently available salvage therapies in similar patient populations.