Actinium Pharmaceuticals, Inc. (ATNM)

Actinium Pharmaceuticals is a clinical-stage biopharmaceutical company developing targeted radiotherapies for oncology. It takes a biology-driven approach to build differentiated, first-in-class radiopharmaceuticals for solid tumors and hematologic malignancies. Its stated aim is to deliver radioconjugates that maximize efficacy while limiting toxicity to healthy tissue, by combining tumor biology and translational medicine with radiochemistry expertise. Its stated goal is to become a fully integrated targeted radiotherapy company.

The pipeline has three parts. In solid tumors, ATNM-400 is an actinium-225 antibody radioconjugate against an undisclosed, non-PSMA antigen. It has pre-clinical activity in metastatic castration-resistant prostate cancer, EGFR-mutant non-small cell lung cancer and breast cancer, and a Zr-89 imaging agent is planned for patient selection. Actimab-A (lintuzumab-Ac-225) is a CD33-targeted radioconjugate intended to deplete myeloid derived suppressor cells in solid tumors. The company plans a Phase 1b basket trial combining it with PD-1 inhibitors in head and neck, lung, glioblastoma and MSI-high colorectal cancers, with initial data expected in the second half of 2026. In hematology, Actimab-A is also being developed with CLAG-M chemotherapy for relapsed/refractory acute myeloid leukemia and for myelodysplastic syndrome, in partnership with the National Cancer Institute under a CRADA. Iomab-B and Iomab-ACT are CD45-targeting conditioning agents, for bone marrow transplant and for cell and gene therapies respectively. The company reports FDA alignment on Phase 2/3 designs for Actimab-A and Iomab-B, and its clinical assets have been studied in over 500 patients across more than 15 trials. It holds about 250 issued patents and pending applications, including composition of matter patents and proprietary cyclotron-based Ac-225 production technology.

The company targets patients with prostate, lung, breast and other solid tumors, as well as AML, MDS and patients needing transplant or cell therapy conditioning. The hematology programs are concentrated in roughly 100 quaternary care centers in the United States and Europe. It notes the market validation from Novartis's Pluvicto and Lutathera and from large pharmaceutical acquisitions and licensing deals in radiopharmaceuticals. It is actively seeking strategic partnerships for its late-stage hematology programs and for its Ac-225 production technology.

On operations, the company manages an end-to-end supply chain covering radioisotope sourcing, targeting agent manufacturing, drug product production and delivery to the point of care. It has run trials at about 50 treatment centers and distributes to roughly 50 hospitals under multiple redundant isotope supply agreements. It is building an internal cGMP radiopharmaceutical manufacturing facility, expected to be operational in the second half of 2026 to supply clinical trials, and pairs it with external manufacturing. It competes with other radiopharmaceutical developers, many focused on PSMA, SSTR2 and FAP targets, and with approved therapies in each indication. The text does not state its headquarters.