Cellectar Biosciences Reports 83.6% ORR, 61.8% MRR and Raises $140M
Cellectar Biosciences achieved 83.6% ORR and 61.8% MRR with a median 17.8-month duration in its Phase 2b CLOVER WaM trial of iopofosine I 131 for relapsed or refractory Waldenström macroglobulinemia, satisfying the FDA’s ≥12-month follow-up requirement for accelerated approval. An oversubscribed $140 million financing will fund the global confirmatory trial and NDA submission.
1. Phase 2b Efficacy Results
The CLOVER WaM study enrolled 55 heavily pretreated patients with relapsed or refractory Waldenström macroglobulinemia, achieving an overall response rate of 83.6% and a major response rate of 61.8%. Median duration of response reached 17.8 months and median progression-free survival was 13.5 months, with durable responses also seen in BTKi-exposed and BTKi-refractory subgroups.
2. FDA Follow-Up Dataset
The updated dataset includes a minimum of 12 months of follow-up for all patients as requested by the FDA, meeting key regulatory expectations for an accelerated approval submission. Consistent depth and durability of responses across subgroups strengthen the case for filing and support initiation of a confirmatory trial.
3. Oversubscribed $140M Financing
Cellectar secured an oversubscribed financing package of up to $140 million led by Nantahala Capital, with participation from several healthcare-focused investors and management. Proceeds will support the global confirmatory study, NDA filing in the US and potential regulatory submissions in Europe, and advancement of the PDC delivery platform.
4. Next Steps and Confirmatory Study
The company plans to initiate a randomized confirmatory trial in the fourth quarter of 2026, evaluating progression-free survival as the primary endpoint in post-first-line, post-BTKi patients. Completion of this study and subsequent data readouts will be pivotal for full approval and commercialization of iopofosine I 131.