Cellectar Biosciences Announces Subset of CLOVER WaM Clinical Trial Data Accepted for Presentation at the American Society of Clinical Oncology Conference 2026

FLORHAM PARK, N.J., April 21, 2026 (GLOBE NEWSWIRE) -- Cellectar Biosciences, Inc. (NASDAQ:CLRB), a late-stage clinical biopharmaceutical company focused on the discovery and development of drugs for the treatment of cancer, today announced the acceptance of an abstract for poster presentation at the American Society of Clinical Oncology Annual Meeting taking place May 29 - June 2 in Chicago, Illinois.

"We are pleased to share data from this important subset of r/r WM patients for whom there are no approved therapies and remaining options are restricted to salvage therapies which provide limited benefit. It is important to note that approximately 60% of drugs used for all WM patients are considered salvage therapies," said Jarrod Longcor, chief operating officer of Cellectar. "The safety and efficacy of iopofosine observed to date are highly encouraging and underscore its potential to address a significant unmet need for patients who progress after BTK inhibitors. We believe these findings further support the potential for iopofosine to emerge as a differentiated therapeutic option in the post-BTKi setting as early as the second line of treatment."

Details of the poster presentation are as follows:

About Waldenstrom's Macroglobulinemia

Waldenstrom's Macroglobulinemia (WM) is a B-cell malignancy characterized by bone marrow infiltration with clonal lymphoplasmacytic cells that produce a monoclonal immunoglobulin M (IgM) that remains incurable with available treatments. The prevalence in the US is approximately 26,000 with 1,500–1,900 patients being diagnosed annually. Approximately 11,500 patients require treatment in the relapsed or refractory setting and there are an estimated 4,700 patients requiring third line or greater therapy. There are also approximately 1,000 patients that have exhausted all current treatment options by third line because they are ineligible or intolerant to those existing therapies. Therefore, the total addressable market for third line or greater therapy is approximately 5,700 patients. There are no U.S. Food and Drug Administration (FDA) approved treatment options for patients progressing on BTKi therapy. BTKi therapies do not demonstrate complete response rates and require continuous treatment.

Non-FDA approved treatments are used in more than 60% of patients. Over 50% of patients are treated with the same or similar treatment from prior lines of therapy. There is an established unmet need for new FDA-approved treatment like iopofosine I 131 that provide a novel mechanism of action, increased deep durable responses, and time limited treatment, especially in heavily pretreated WM patients.

About Cellectar Biosciences, Inc.

Cellectar Biosciences is a late-stage clinical biopharmaceutical company focused on the discovery and development of proprietary drugs for the treatment of cancer, independently and through research and development collaborations. The company's core objective is to leverage its proprietary Phospholipid Drug Conjugate™ (PDC) delivery platform to develop the next-generation of cancer cell-targeting treatments, delivering improved efficacy and better safety as a result of fewer off-target effects.

The company's product pipeline includes iopofosine I 131, which is a PDC designed to provide targeted delivery of iodine-131 (radioisotope). Iopofosine I 131 has been tested in Phase 2b trials as a treatment for relapsed or refractory Waldenström Macroglobulinemia (WM), in relapsed or refractory multiple myeloma (MM) and central nervous system (CNS) lymphoma. The CLOVER-2 Phase 1b study is evaluating iopofosine I 131 in pediatric patients with high-grade gliomas, for which Cellectar is eligible to receive a Pediatric Review Voucher from the FDA upon approval. The FDA has granted iopofosine I 131 Breakthrough, six Orphan Drug, four Rare Pediatric Drug and two Fast Track Designations for various cancer indications, and the EMA has granted iopofosine I 131 PRIority MEdicines (PRIME) designation.

Cellectar is also developing CLR 121125 (CLR 125), an iodine-125 Auger-emitting program targeted for solid tumors, such as triple negative breast (TNBC), lung, and colorectal cancer, and is currently being evaluated in a Phase 1b study for TNBC, which will determine the recommended dose for the subsequent Phase 2 trial. CLR 125 has been well tolerated in vivo and has demonstrated strong preclinical data showing reduction or inhibition of solid tumor growth.

In addition to these assets, the Cellectar team is developing CLR 121225 (CLR 225), an actinium-225 based program targeting solid tumors in indications with significant unmet need, such as pancreatic cancer, as well as proprietary preclinical PDC chemotherapeutic programs and multiple partnered PDC assets.

For more information, please visit https://www.cellectar.com/ or join the conversation by liking and following us on the company's social media channels: X, LinkedIn, and Facebook.

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