Cellectar Biosciences, Inc. (Nasdaq:CLRB), an oncology-focused, clinical stage biotechnology company (the “company”), today announces the design of the multiple dose fifth cohort of its Phase I dose escalation safety trial of lead PDC™ compound, CLR 131, in relapse or refractory multiple myeloma. Cohort 5 will utilize two 15.625 mCI/mdoses given one week apart with the total combined dose equaling 31.25 mCi/m2, the same total dose provided to patients that resulted in a partial response in Cohort 4. In previous cohorts, CLR 131 was given in a single infusion.

In September, the trial’s Data Monitoring Committee (DMC) determined that the fourth cohort single dose of 31.25 mCi/m2 was safe and tolerated. In addition, the DMC determined that the use of a split, or repeat dose might be advantageous. Given internal company data and recently announced results of preclinical studies in which 2 doses of CLR 131 demonstrated a statistically significant improvement in survival benefits and reduction of tumor volume in multiple mouse models (April 27, 2017), the company has enhanced the study’s protocol such that subsequent cohorts will include repeat dosing.

“Given the encouraging results we’ve observed to date in previous cohorts, we hope to see similar, or perhaps even improved safety results in this arm of the trial,” said Natalie Callander, M.D., professor of medicine, director, University of Wisconsin Carbone Cancer Center Myeloma Clinical Program, and the study’s lead investigator. “Previous participants have asked us if it was possible to receive additional doses, as this therapy has been so well tolerated.” Read the full story here.