Phospholipid-targeted radiopharmaceutical with strong Phase 2b WM data files for accelerated approval on single-arm evidence — runway expires before Phase 3 data

Cellectar Biosciences is a clinical-stage company developing a targeted radiopharmaceutical for Waldenstrom Macroglobulinemia, a blood cancer, which is not yet approved.

Iopofosine I-131 achieved 61.8% major response rate and 83.6% ORR in relapsed Waldenstrom Macroglobulinemia, with an 83-month post-BTKi subset showing 79.2% MRR, supporting an accelerated approval filing on single-arm data. The thesis resolves on whether FDA grants accelerated approval on that non-randomized package before the Q2 2027 runway is exhausted. Single-arm data remain the structural vulnerability: regulatory rejection without a confirmatory path would be difficult to recover from given the financing structure.