Cellectar Biosciences Advances Iopofosine I 131 Toward European Approval for Waldenström's Macroglobulinemia
Key Insights
Cellectar Biosciences plans to submit a Conditional Marketing Authorization application to the European Medicines Agency (search) for iopofosine I 131 (search) in Waldenström's macroglobulinemia (search) in Q3 2026, with potential approval in early 2027.
The FDA has granted Breakthrough Therapy Designation for iopofosine I 131 (search) in relapsed/refractory Waldenström's macroglobulinemia (search) and confirmed an accelerated approval pathway.
The company will begin dosing patients in a Phase 1b study of CLR 125 for triple-negative breast cancer (search) in Q1 2026, with interim data expected mid-2026.
Cellectar Biosciences has outlined ambitious regulatory milestones for 2026, positioning its lead radiotherapeutic iopofosine I 131 (search) for potential European market approval in early 2027 for the treatment of Waldenström's macroglobulinemia (search) (WM). The late-stage clinical biopharmaceutical company announced its strategic initiatives at the Biotech Showcase during the 44th Annual JP Morgan Healthcare Conference.
Regulatory Progress for Iopofosine I 131
Following guidance from the European Medicines Agency (search)'s Scientific Advice Working Party, Cellectar expects to submit a Conditional Marketing Authorization application for iopofosine I 131 (search) in WM during the third quarter of 2026. The submission is based on data from the company's CLOVER WaM Phase 2 study.
"We are focused on receiving a conditional marketing approval in 2027 from the EMA impacting approximately thirty countries, which collectively possess a larger WM population than the U.S.," said James Caruso, president and CEO of Cellectar.
The company has also made significant progress with U.S. regulatory authorities. The FDA granted Breakthrough Therapy Designation for iopofosine I 131 (search) in relapsed/refractory WM in 2025 and confirmed a traditional accelerated approval pathway. The FDA-recommended post-BTKi indication positions iopofosine I 131 as a treatment option as early as the second line, substantially expanding the available patient population in the U.S. market.
Expanding Pipeline Development
Cellectar plans to initiate patient dosing in a Phase 1b study of CLR 125 for triple-negative breast cancer (search) (TNBC) in the first quarter of 2026, with interim data expected mid-2026. CLR 125 is an Auger-emitting iodine-125 (search) program that builds on preclinical data showing growth inhibition and tumor volume reduction in this challenging-to-treat cancer.
The company also presented compelling data from the CLOVER-2 Phase 1b study in relapsed/refractory pediatric high-grade glioma (search), demonstrating extended progression-free survival and a favorable safety profile. Additionally, Cellectar is preparing its actinium-based CLR 225 (search) program for first-in-human trials in pancreatic cancer (search).
Proprietary Platform Technology
Cellectar's product development is built on its proprietary Phospholipid Drug Conjugate (PDC) delivery platform, designed to develop next-generation cancer cell-targeting treatments that deliver improved efficacy and better safety. The company's pipeline includes iopofosine I 131 (search) for hematologic and solid tumor cancers, CLR 125 targeting solid tumors including triple-negative breast, lung and colorectal cancers, and CLR 225 (search) for solid tumors with significant unmet need.
Regulatory Recognition
Iopofosine I 131 (search) has received extensive regulatory recognition, with the FDA granting six Orphan Drug, five Rare Pediatric Drug, and two Fast Track Designations for various cancer indications. The European Medicines Agency (search) has also granted PRIME and orphan drug designations for the treatment of WM. Upon approval, Cellectar is eligible to receive a Pediatric Review Voucher from the FDA for its pediatric high-grade glioma (search) indication.
Financial Position and Strategic Outlook
The company raised approximately $15.2 million through financings and warrant exercises in 2025 to support pipeline development and regulatory milestones. Cellectar continues to evaluate strategic collaborations for commercialization of iopofosine I 131 (search) while exploring non-dilutive funding opportunities.
"With an established iopofosine I 131 (search) regulatory strategy for both EMA and FDA, and promising data across our pipeline, we are entering 2026 with strong momentum and multiple opportunities," Caruso stated. "We believe these initiatives position Cellectar to deliver meaningful therapies for patients and create significant value for shareholders."