Actinium Pharmaceuticals is making strides in the development of Antibody Radiation Conjugates (ARCs) and targeted radiotherapies, with a focus on improving outcomes for patients with relapsed or refractory acute myeloid leukemia (r/r AML) and solid tumors. The company highlighted regulatory clearances and development updates for its Iomab-B, Actimab-A, and Iomab-ACT clinical programs, alongside its third-quarter financial results.
Actimab-A: Streamlined Phase 2/3 Trial
Actinium has aligned with the FDA on an operationally seamless Phase 2/3 trial to evaluate Actimab-A in combination with CLAG-M (cladribine, cytarabine, and granulocyte colony-stimulating factor) for patients with r/r AML. This trial design is expected to reduce the time and resources required compared to separate Phase 2 and Phase 3 trials. The Phase 2 portion will focus on optimizing the dose of Actimab-A with CLAG-M, while the Phase 3 portion will compare the optimized dose of Actimab-A + CLAG-M against CLAG-M alone.
Actimab-A has also been selected by the National Cancer Institute (NCI) for its myeloMATCH precision medicine program, which is open to patients with AML and myelodysplastic syndromes (MDS).
Iomab-ACT: Expanding into Cell and Gene Therapies
The FDA has cleared Investigational New Drug (IND) applications for two Iomab-ACT trials: a commercial CAR-T study led by the University of Texas Southwestern (UTSW) and a sickle cell transplant trial led by Columbia University. The UTSW CAR-T trial is expected to begin enrolling patients in the first quarter of 2025, with initial clinical data anticipated by the end of the year. The Columbia University sickle cell transplant trial will assess Iomab-ACT as a targeted conditioning agent before bone marrow transplant (BMT) in a non-malignant hematology setting.
Iomab-B: Seeking Strategic Partnership for Phase 3 Trial
Actinium is actively seeking a U.S. strategic partner to advance the clinical development of Iomab-B, including a Phase 3 trial. The company has aligned with the FDA on the patient population for a head-to-head Phase 3 trial, which will evaluate allogeneic BMT using Iomab-B plus a reduced intensity conditioning regimen of fludarabine and total body irradiation (Flu/TBI) versus allogeneic BMT using reduced intensity conditioning comprised of cyclophosphamide plus Flu/TBI. This trial will enroll adult patients with active AML with blast counts greater than 5% and less than 20%.
Prior to initiating the Phase 3 trial, a dose optimization trial will be conducted to determine the appropriate dose of Iomab-B based on radiation to the bone marrow.
Financial Position
Actinium reported cash and cash equivalents of approximately $78.6 million as of September 30, 2024. The company expects these funds to support operations into 2027.
