Actinium Pharmaceuticals, Inc.  announced that interim data from its ongoing Actimab-A CLAG-M Phase 1 combination trial in relapsed or refractory Acute Myeloid Leukemia (AML) were presented at the 62ndAmerican Society of Hematology (ASH) annual meeting. ASH Oral Presentation: A Phase I study of Lintuzumab Ac225 in Combination with CLAG-M Chemotherapy in Relapsed/Refractory AML. In the third and planned final dose cohort of Actimab-A CLAG-M, 100% of evaluable patients achieved remission.  The trial, which is being conducted at the Medical College of Wisconsin (MCW), is advancing to a fourth dose cohort of 1.0 µCi/kg.  Across the first three cohorts, 67% (10/15) patients treated with 0.25, 0.50 and 0.75 µCi/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 (Measurable Residual Disease) negative indicating a deep remission with no detectable disease.  MRD negativity is defined as =0.1% AML cells.  These results, which include subtherapeutic doses of Actimab-A in the first two dose cohorts, 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. Actinium's CD33 program is evaluating the clinical utility of Actimab-A, an Antibody Radiation Conjugate (ARC) comprised of the anti-CD33 mAb lintuzumab linked to the potent alpha-emitting radioisotope Actinium-225 or Ac-225.  CD33 is expressed in the majority of patients with AML and myelodysplastic syndrome, or MDS, as well as patients with multiple myeloma.  The CD33 development program is driven by data from over one hundred treated patients, including a Phase 1/2 trial where Actimab-A produced a remission rate as high as 69% as a single agent.  This clinical data is shaping a two-pronged approach for the CD33 program, where at low doses the Company is exploring its use for therapeutic purposes in combination with other modalities and at high doses for use for targeted conditioning prior to bone marrow transplant.  Actinium currently has multiple clinical trials ongoing including the Phase 1 Actimab-A CLAG-M and Phase 1/2 Actimab-A venetoclax combination trials and is exploring additional CD33 ARC combinations with other therapeutic modalities such as chemotherapy, targeted agents or immunotherapy.