Actinium Says DMC Recommends Phase 3 SIERRA Trial Continue To Full Enrolment Of 150 Patients

(RTTNews) - Actinium Pharmaceuticals, Inc. (ATNM) said Tuesday that the independent Data Monitoring Committee or DMC has completed the single ad hoc interim analysis of the pivotal Phase 3 SIERRA study of Iomab-B for bone marrow transplant (BMT) conditioning in patients aged above 55 with active relapsed or refractory Acute Myeloid Leukemia (R/R AML).

The SIERRA trial is a randomized, controlled study evaluating outcomes of patients receiving Iomab-B and a BMT compared to outcomes of patients on the control arm, who may proceed to BMT if they achieve a required complete remission (CR).

The DMC, after review of unblinded data that includes the study's primary endpoint of durable Complete Remission or dCR of at least 180 days, has recommended that the study continue as planned to full enrollment of 150 patients. The trial is currently over 75 percent enrolled.

Actinium noted that detailed safety and feasibility data from 75 percent of patient enrollment presented at the ASH 2020 Annual Meeting highlighted that all the 49 patients receiving a therapeutic dose of Iomab-B in SIERRA successfully proceeded to BMT and achieved engraftment, the first sign of BMT success, without delay.

This compared to 16 percent of patients in the control arm who received physician's choice of salvage therapies. The control arm includes a wide range of salvage therapies, including targeted agents like venetoclax, as there is no standard of care in this setting.

Actinium said it did not receive the unblinded primary and secondary endpoint efficacy data from SIERRA.

"We are encouraged by the DMC's recommendation to continue the SIERRA trial as planned and that there continues to be no safety concerns from the Iomab-B arm. All of us at Actinium are intensely focused on completing the final portion of patient enrollment in the SIERRA trial," said Dr. Mark Berger, Actinium's Chief Medical Officer. Actinium noted that the SIERRA trial remains the only randomized Phase 3 trial to offer potentially curative bone marrow transplant or BMT as an option for patients with active relapsed or refractory AML.