Cellectar Biosciences to Pursue Strategic Options for Iopofosine I 131, Prioritizes Solid Tumor Radiotherapies
Key Insights
Cellectar Biosciences is exploring strategic alternatives for iopofosine I 131 (search) after recent FDA feedback on regulatory pathways.
The company will focus on advancing CLR 121225 and CLR 121125, alpha- and Auger-emitting radioconjugates, into Phase 1 trials for solid tumors (search).
Cellectar anticipates filing Investigational New Drug applications for both CLR-121225 and CLR-121125 in the first half of 2025.
Cellectar Biosciences, Inc. (NASDAQ: CLRB) announced a strategic shift in its clinical development programs, prioritizing radiotherapeutic assets for solid tumors (search) while seeking strategic options for iopofosine I 131 (search). The decision follows recent communications with the U.S. Food and Drug Administration (FDA) regarding the regulatory path for iopofosine I 131, a phospholipid ether drug conjugate (PDC) in late-stage clinical development.
Strategic Realignment
Cellectar's decision to explore strategic options for iopofosine I 131 (search) stems from the FDA's guidance on a confirmatory study to support accelerated approval. The company had previously conducted the CLOVER-WaM study based on earlier FDA communications, anticipating that positive major response rate (MRR) data could support accelerated approval for Waldenstrom’s macroglobulinemia (search) (WM). However, a recent Type-C meeting with the FDA indicated that a submission would require MRR data from CLOVER-WaM and enrollment in a randomized, controlled confirmatory study assessing progression-free survival (PFS).
James Caruso, president and CEO of Cellectar, stated, "While iopofosine I 131 (search)’s positive WM data along with the high unmet medical need for these patients support further investment, we have determined that such a program may best be brought to market by a larger organization with greater resources."
Focus on Radiotherapeutic Assets
Cellectar will now concentrate on advancing its earlier-stage clinical programs, particularly those involving alpha- and Auger-emitting radioconjugates. The company plans to file Investigational New Drug (IND) applications in the first half of 2025 for CLR 121225, an actinium-225 based program, and CLR 121125, an iodine-125 Auger-emitting program. These programs will target solid tumors (search), with Phase 1 clinical studies expected to initiate following IND clearance.
Preclinical data have demonstrated robust in vivo activity, tolerability, and excellent targeting and uptake in solid tumor models for both CLR-121225 and CLR-121125. Cellectar believes this approach will expedite the achievement of safety and proof-of-concept data in patients.
Corporate Restructuring
To support this strategic reprioritization, Cellectar is implementing a corporate restructuring that includes an immediate reduction in headcount of approximately 60%, expected to be complete by the end of the fourth quarter 2024. The company anticipates that these measures will extend its cash runway into the third quarter of 2025.
"We are being methodical in our efforts to reorganize the company with the goal of conserving cash while maintaining the flexibility to execute immediate priorities and build for long-term growth and value creation," said Mr. Caruso.
Iopofosine I 131 Clinical Development
Iopofosine I 131 (search) remains under evaluation in Phase 2b studies for relapsed or refractory multiple myeloma (search) (MM) and central nervous system (CNS) lymphoma, as well as the CLOVER-2 Phase 1b study for pediatric patients with high-grade gliomas (search). The FDA has granted iopofosine I 131 Orphan Drug and Fast Track Designations for various cancer indications.