Actinium Announces Positive Pivotal Phase 3 SIERRA Trial Results of Iomab-B Showcased to the European Transplant Community

Actinium Pharmaceuticals, a leader in the development of targeted radiotherapies, today announced that the positive results from the pivotal Phase 3 SIERRA Trial of Iomab-B were presented in an oral presentation at the European Society for Blood and Marrow Transplantation (EBMT) 49th Annual Meeting that was held in Paris, France April 23 – 26, 2023. Europe represents a large market opportunity with approximately twice as many transplants performed in Europe compared to the United States.The SIERRA trial is the first randomized Phase 3 trial to take unfit, transplant ineligible patients with active relapsed or refractory (r/r) acute myeloid leukemia (AML) age 55 and above to bone marrow transplant (BMT), which was feasible due to Iomab-B’s novel targeted radiotherapy approach that allows patients to receive a BMT without achieving a Complete Remission (CR).

As previously presented at the 2023 Tandem Meetings: Transplantation & Cellular Therapy Meetings of the American Society for Transplantation and Cellular Therapy (ASTCT) and the Center for International Blood & Marrow Transplant Research (CIBMTR) in February 2023, Iomab-B enabled unprecedented 100% access to BMT in half the time, 29 days vs. 66.5 days, with 100% of Iomab-B patients achieving engraftment, the first sign of BMT success. Iomab-B met the study’s primary endpoint of dCR of 6-months following initial complete remission after BMT with high statistical significance (p-value of <0.0001) with only patients receiving Iomab-B achieving dCR. The Iomab-B patients achieving dCR had a 92% 1-year survival rate and a 60% 2-year survival rate, which represents a potential cure, and median overall survival (OS) has not been reached in the patients achieving dCR.

Sandesh Seth, Actinium’s Chairman and CEO, said, “Iomab-B and the SIERRA trial represent a paradigm change for patients with r/r AML by making a BMT and its curative potential a reality for the significant number of patients who cannot achieve a CR or tolerate current induction and conditioning therapies. We’re thrilled the SIERRA results were showcased to the European transplant community, as Europe represents a large commercial market with twice as many BMTs performed in Europe compared to the US each year. With our efforts fully underway to complete and submit our BLA for Iomab-B with the FDA by the end of 2023, we are committed to bringing Iomab-B to r/r AML patients globally and look forward to working with Immedica, our European, Middle East and North African (EUMENA) partner for their subsequent marketing authorization application (MAA) with the European Medicines Agency. With these positive results in hand, we’re eager to continue to build awareness for Iomab-B globally and to launch an early access program for Iomab-B in the U.S. as well as launch life cycle planning initiatives in the second half of this year to leverage Iomab-B’s potential across blood cancers.”

Dr. Avinash Desai, Actinium’s Chief Medical Officer, added, “The efficacy and tolerability of Iomab-B in these heavily pre-treated patients with active, high-risk r/r AML enrolled in the SIERRA trial is unprecedented. Despite 10 drug approvals for AML since 2017, approximately 30% of patients never achieve a remission and over 50% develop relapsed or refractory disease, which is associated with dismal survival outcomes of 2-4 months. BMT remains the only potential curative treatment option for r/r AML patients, but current clinical practice precludes the overwhelming majority of r/r AML patients from BMT due to the need to first achieve a remission and the use of highly toxic, non-targeted chemotherapies for conditioning. Based on the reaction to the SIERRA results from BMT physicians in the U.S. and now Europe, if approved, Iomab-B can be practice changing by enabling r/r AML patients with active disease, one of the largest segments of AML, to access BMT in days, via a single therapeutic infusion, without having to first achieve a remission.”