Actinium Pharmaceuticals, Inc. announced that 100% of evaluable patients in the third and planned final dose cohort of the Actimab-A CLAG-M Phase 1 trial being conducted at the Medical College of Wisconsin (MCW) achieved remission. Across all three cohorts, 67% or 10/15 patients treated with 0.25, 0.50 and 0.75 uCi/kg of Actimab-A and the standard regimen of CLAG-M achieved a Complete Remission (CR) or Complete Remission with inadequate hematopoietic recovery (CRi). Further, 83% of patients (10/12) who received 3 or fewer prior lines of treatment achieved CR or CRi. Notably, 70% of CR/CRi patients were MRD negative indicating a deep remission with no detectable disease. These results which include subtherapeutic doses of Actimab-A in the first two dose cohorts and represent a marked improvement over CLAG-M treatment alone (ORR: 55%, MRD negativity: 39%) implying potential mechanistic synergy. This novel Phase 1 combination trial is for patients with relapsed or refractory acute myeloid leukemia (R/R AML) age 18 and above deemed medically fit for cytotoxic chemotherapy. This data has been accepted for oral presentation at the 2020 American Society of Hematology (ASH) annual meeting that is being held virtually December 5-8, 2020. Patients enrolled on this study to date had intermediate (5/15, 33%) or adverse (10/15, 67%) cytogenetics. Patients received a median of 2 lines of prior therapies (range 1-5) with 47% of patients (7/15) previously receiving venetoclax with a hypomethylating agent and 53% of patients (8/15) having undergone an allogeneic BMT and then relapsed prior to Actimab-A CLAG-M. In the third dose cohort of 0.75 uCi/kg, 100% of evaluable patients (3/3) achieved complete remission [1 CR, 2 Complete Remission with inadequate platelet recovery (CRp)] with 2 patients being MRD negative and the other patient having only 0.2% AML cells detected. MRD negativity is defined as =0.1% AML cells. Investigators at MCW determined that the combination had a clinically acceptable safety profile, including at the planned final dose cohort of 0.75 uCi/kg, and have therefore amended this protocol to add a fourth dose cohort of 1.0 uCi/kg, which is currently screening and enrolling patients.