Cellectar's Iopofosine I 131 Receives FDA Breakthrough Designation for WM

Cellectar Biosciences, Inc., a prominent biopharmaceutical company specializing in cancer treatment innovations, recently announced a significant milestone. The U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation for iopofosine I 131, a novel therapeutic agent designed to treat relapsed or refractory Waldenstrom macroglobulinemia (r/r WM), a challenging subtype of lymphoplasmacytic lymphoma. This designation is a pivotal step in expediting the development and review of treatments aimed at life-threatening conditions, asserting that iopofosine I 131 has the potential to deliver substantial clinical improvements over existing therapies.

Waldenstrom macroglobulinemia remains a complex disease with limited treatment options, necessitating innovation in therapeutic approaches. The International Waldenstrom’s Macroglobulinemia Foundation underscores the incurability of WM with current treatments, hence the urgent need for novel mechanisms to tackle this malignancy. Iopofosine I 131, utilizing phospholipid ether as a radioconjugate monotherapy, emerges as a promising candidate to address this unmet medical need.

James Caruso, President and CEO of Cellectar Biosciences, emphasized the significance of the Breakthrough Therapy Designation, stating that it highlights the drug's potential to improve patient outcomes significantly. He noted the favorable safety profile and robust clinical data supporting iopofosine I 131, which positions it as an attractive prospect for collaborations and accelerated development pathways in both the United States and Europe.

Supporting this breakthrough, data from the Phase 2 CLOVER WaM study demonstrated an impressive overall response rate (ORR) of 83.6% and a major response rate (MRR) of 58.2%, surpassing the primary endpoint requirement of a 20% MRR. These findings were presented at the 66th Annual American Society of Hematology Conference by Dr. Sikander Ailawadhi from the Mayo Clinic.

In addition to the Breakthrough Therapy Designation, iopofosine I 131 has been awarded Fast Track and Orphan Drug Designations by the FDA. The European Medicines Agency (EMA) has also granted Orphan Drug Designation and PRIME Designation for the treatment of r/r WM. Cellectar Biosciences is seeking further guidance from the EMA to evaluate whether the Phase 2 CLOVER WaM study data meets the criteria for conditional marketing authorization. A decision from the EMA is anticipated by late July 2025.

Cellectar's investment in iopofosine I 131 extends beyond WM, with ongoing studies for other conditions such as relapsed or refractory multiple myeloma and central nervous system lymphoma. The company's pipeline includes additional promising programs targeting solid tumors with significant unmet needs, including CLR 121225 and CLR 121125, among others.

About Breakthrough Therapy Designation, this FDA program fast-tracks the development and review process for drugs that show preliminary evidence of substantial improvement over existing treatments for serious diseases. It fosters increased interaction with the FDA, potentially leading to a six-month priority review of a New Drug Application.

Cellectar Biosciences continues to spearhead innovation in cancer treatment, leveraging its proprietary Phospholipid Drug Conjugate™ (PDC) delivery platform to enhance targeted treatment efficacy and safety. Their strategic focus on developing next-generation cancer therapies positions them as a leading entity in the biopharmaceutical landscape.

As the company prepares for potential collaborations and further regulatory advancements, the momentum generated by the FDA's designation underscores the transformative potential of iopofosine I 131 in addressing the complexities of Waldenstrom macroglobulinemia and other challenging cancer types.