Actinium Pharmaceuticals: Phase 3 SIERRA results of Iomab-B published in JCO

Actinium Pharmaceuticals announced the publication of the Phase 3 SIERRA results of Iomab-B in the peer-reviewed Journal of Clinical Oncology. The article, titled, “Randomized Phase III SIERRA Trial of 131I-Apamistamab Before Allogeneic Hematopoietic Cell Transplantation vs Conventional Care for Relapsed/Refractory Acute Myeloid Leukemia” and is available online on the ASCO Journal of Clinical Oncology website. The Phase 3 SIERRA trial was a randomized, multi-center, controlled trial that enrolled 153 patients aged 55 and above with active relapsed or refractory Acute Myeloid Leukemia, including heavily pre-treated patients and those with high-risk characteristics such as a TP53 mutation. The SIERRA trial compared outcomes of patients receiving Iomab-B and a bone marrow transplant to physician’s choice of salvage chemotherapy and standard allogeneic BMT in the control arm. The SIERRA trial met the primary endpoint of durable Complete Remission of 6-months following initial complete remission after BMT with high statistical significance with 22% of patients achieving dCR in the Iomab-B arm compared to 0% of patients in the control arm. A significant improvement in Event Free Survival, a secondary endpoint of the SIERRA trial with a Hazard Ratio was also achieved. SIERRA did not meet the secondary endpoint of overall survival on an intent to treat basis analysis due to the high crossover rate with nearly 60% of control arm patients receiving Iomab-B followed by a BMT.