Actinium Prepares to Showcase Breakthrough Radiotherapy Data at Premier Cancer Conference

NEW YORK, NY – April 06, 2026 – Actinium Pharmaceuticals is poised to present compelling new preclinical data at the upcoming American Association for Cancer Research (AACR) Annual Meeting, signaling potentially significant advancements in the fight against both solid tumors and blood cancers. The New York-based company announced that findings for two of its leading drug candidates, ATNM-400 and Actimab-A, underscore the power and versatility of its targeted radiotherapy platform, which uses the potent alpha-emitter Actinium-225 (Ac-225) to destroy cancer cells.

The presentations, scheduled for April 21 in San Diego, are expected to draw considerable attention from the oncology community. The AACR Annual Meeting is one of the world's most prestigious gatherings for cancer research, where the latest breakthroughs are unveiled. For Actinium, these posters represent a critical validation of its long-term strategy and its pioneering work in one of oncology's most exciting new fields.

A New Frontier in Precision Oncology

At the heart of Actinium's approach is targeted alpha-particle therapy, a sophisticated method of delivering radiation directly to cancer cells. The technology pairs a potent radioactive isotope, Ac-225, with a targeting molecule that seeks out specific proteins, or antigens, on the surface of tumors. Once attached, the Ac-225 releases high-energy alpha particles.

Unlike other forms of radiation, alpha particles are powerful but have an extremely short range, typically traveling less than the width of a few cells. This characteristic allows them to deliver a lethal dose of radiation to the cancer cell, causing complex double-strand breaks in its DNA that are exceptionally difficult for the cell to repair. This localized, high-impact assault minimizes damage to surrounding healthy tissue, a common and debilitating side effect of traditional radiation and chemotherapy. This 'smart bomb' approach represents a major leap forward in precision medicine.

"These new data further validate the strength and versatility of our Ac-225 radiotherapy platform," said Sandesh Seth, Actinium's Chairman and CEO, in a statement. He emphasized that the findings reinforce the company's strategy to build a differentiated pipeline with multiple value-driving opportunities.

Tackling Solid Tumors and Treatment Resistance

One of the key presentations will focus on ATNM-400, a first-in-class radioconjugate designed for solid tumors. The new preclinical data reportedly demonstrates broad, or "pan-tumor," efficacy across multiple challenging cancer models, including metastatic castration-resistant prostate cancer (mCRPC), non-small cell lung cancer (NSCLC), and breast cancer.

Perhaps most significantly, the data suggests ATNM-400 is active even in tumors that have become resistant to current targeted therapies. Treatment resistance is a major hurdle in oncology, where tumors can evolve to evade the effects of drugs, leading to relapse. A therapy that can overcome this resistance would address a profound unmet medical need for countless patients.

ATNM-400 also targets a novel antigen distinct from well-known targets like PSMA, which is the focus of several other prostate cancer radiotherapies. This differentiation could be crucial, potentially offering a new treatment avenue for patients whose tumors do not express PSMA or who have progressed on PSMA-targeted treatments. The company's claim of ATNM-400 as a potential "first-in-class asset in large solid tumor indications" will be closely scrutinized by researchers and investors at the AACR meeting.

Rewriting the Rules for Acute Myeloid Leukemia

While ATNM-400 targets solid tumors, Actinium's other highlighted candidate, Actimab-A, is focused on a difficult-to-treat blood cancer: acute myeloid leukemia (AML). The upcoming presentation will reveal a newly identified mechanism of action that could explain its impressive clinical activity.

According to the company, Actimab-A induces "transcriptional reprogramming" within the cancer cells. In essence, the drug appears to do more than just kill cells directly; it changes their fundamental genetic programming, making them more susceptible to standard-of-care AML therapies. This novel mechanism helps explain the drug's mutation-agnostic efficacy, meaning it can be effective across a wide range of AML patients, regardless of the specific genetic mutations driving their disease. This is a critical advantage in a genetically complex and diverse cancer like AML.

Actimab-A has already shown promise in improving survival in relapsed or refractory AML patients and is advancing toward a pivotal Phase 2/3 trial. The drug's development is also supported by a Cooperative Research and Development Agreement (CRADA) with the prestigious National Cancer Institute (NCI), lending further credibility to its clinical potential.

A Strategic Bet on a Diversified Platform

The dual presentations at AACR highlight Actinium's broader corporate strategy: leveraging its deep expertise in Ac-225 to build a diversified oncology pipeline that spans both solid tumors and hematologic malignancies. This two-pronged approach de-risks the company's portfolio and maximizes the potential applications of its core technology.

Beyond ATNM-400 and Actimab-A, the company's pipeline includes targeted conditioning agents like Iomab-B, designed to prepare patients for bone marrow transplants. This demonstrates a comprehensive vision for deploying radiopharmaceuticals at multiple stages of cancer treatment.

Critically, Actinium has also focused on a major historical bottleneck for alpha-emitter therapies: the supply of Ac-225. The company holds an extensive intellectual property portfolio of approximately 250 patents and applications, including those related to the cyclotron-based production of the isotope. Securing a reliable and scalable supply chain for Ac-225 could provide Actinium with a formidable competitive advantage as the field of radiopharmaceuticals continues to expand.

As the oncology world turns its eyes to San Diego, the data presented in the "Radiopharmaceutical Platforms for Theranostic Precision Oncology" session will be a key indicator of the future of this therapeutic class. For Actinium Pharmaceuticals, the presentations on April 21st represent more than just a scientific update; they are a testament to a long-term vision for transforming cancer treatment by harnessing the power of the atom.