Actinium Pharmaceuticals, Inc. Announces Iomab-B Phase 3 Sierra Trial Results Demonstrating Survival Benefit in High-Risk Relapsed or Refractory Acute Myeloid Leukemia Patients with TP53 Mutations Accepted for Oral Presentation At the 50Th European Bone Marrow Transplant Annual Meeting

Actinium Pharmaceuticals, Inc. announced that results from the Phase 3 SIERRA trial of Iomab-B in patients with a TP53 mutation have been accepted for oral presentation at the 50th Annual meeting of the European Bone Marrow Transplant Society (EBMT) being held April 14 ? 17, 2024, in Glasgow, Scotland. Iomab-B is a targeted radiotherapy conditioning agent comprised of an anti-CD45 monoclonal antibody and Iodine-131 radioisotope payload.

The Phase 3 SIERRA trial enrolled 153 patients with active relapsed or refractory acute myeloid leukemia (r/r AML) and compared outcomes of patients receiving Iomab-B and a bone marrow transplant (BMT) to those of patients receiving physician's choice of care in the control arm. In total, 24% of patients (37/153) in the SIERRA trial had a TP53 mutation, which is associated with poor outcomes, and 27 of the TP53 positive patients received Iomab-B. Iomab-B met the primary endpoint of durable Complete Remission (dCR) in the SIERRA trial with high-statistical significance (p<0.0001) and 100% of patients receiving a therapeutic dose of Iomab-B achieved BMT access and engagement.