Demonstrated Favorable Safety Profile and Preliminary Clinical Activity in
Relapsed/Refractory Multiple Myeloma
Publication Supports Continued Development of Iopofosine I 131 as a Novel Targeted
Radiotherapeutic Across Multiple B-Cell Malignancies
FLORHAM PARK, N.J., July 15, 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 publication of results from a Phase 1 dose-escalation study evaluating iopofosine I 131 in combination with low-dose dexamethasone in 31 patients with heavily pretreated relapsed/refractory multiple myeloma (r/r MM). The manuscript, titled "A Phase I Trial of Iopofosine I 131 and Dexamethasone in Patients with Relapsed/Refractory Multiple Myeloma," was published in the peer-reviewed journal, Cancers.
"Iopofosine I 131 represents a differentiated therapeutic approach for patients with relapsed or refractory multiple myeloma who have limited remaining treatment options," said Sikander Ailawadhi, M.D., professor of medicine, division of hematology/oncology, Mayo Clinic, Jacksonville, Florida and lead author of the publication. "The study demonstrated manageable toxicity with adverse events being essentially limited to cytopenias, encouraging disease control, and evidence of antitumor activity in a heavily pretreated population, supporting the potential of this novel targeted radiotherapeutic in these most fragile patients. The predictability and recovery of the cytopenias support its potential for repeat dosing strategies in future clinical development."
Highlights of the Data:
The study evaluated both single-dose and fractionated-dose regimens of iopofosine I 131 in 31 heavily pretreated r/r MM patients, many of whom had exhausted available treatment options.
Among 26 efficacy-evaluable patients:
Clinical activity appeared more pronounced in patients receiving higher total administered doses
84.6% achieved stable disease or better following treatment
30% overall response rate observed among evaluable patients (n=10) receiving at least 60 mCi of iopofosine I 131
The overall response rate was 15.4%, with four patients achieving partial responses
Investigators reported a favorable and manageable safety profile, with adverse events primarily consisting of predictable and reversible hematologic toxicities
No new safety signals were identified, and non-hematologic adverse events were generally low grade