Together the allowances deepen protection across two priority franchises and reinforce a patent estate of approximately 250 issued and pending patents and patent applications worldwide

NEW YORK, May 29, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE:ATNM) (Actinium or the Company), a leader in the development of targeted radiotherapies, today announced that the Canadian Intellectual Property Office (CIPO) has issued Notices of Allowance for two patent applications spanning the Company's Actimab-A and Iomab-ACT programs. The allowances broaden Actinium's intellectual property protection across both hematologic malignancies and next-generation conditioning for gene-edited cell-based therapies in Canada, an important market within the Company's growing global patent estate. These Canadian allowances build on protection already secured in other major markets, including a previously granted Japanese patent for the Actimab-A program and an issued U.S. patent for the Iomab-ACT program, with additional applications pending in the United States, Europe and China.

The Notices of Allowance follow examination by CIPO, with issuance of the patents expected in the ordinary course. The allowances deepen Actinium's intellectual property protection across two of its priority franchises and reinforce a global patent estate of approximately 250 issued and pending patents and patent applications.

"These two allowances reflect the breadth and depth of the innovation across our radiotherapy platform and our commitment to protecting it in every key market," said Adeela Kamal, Ph.D., EVP-R&D of Actinium Pharmaceuticals. "Securing coverage for both our Actimab-A CLAG-M combination in AML and our Iomab-ACT conditioning approach for gene-edited cell-based therapies underscores the strength of our science and the durability of the franchises we are building. We will continue to expand and defend our intellectual property worldwide as we advance these programs toward patients."

Actimab-A + CLAG-M Combination for AML

The allowed application covers the use of Actimab-A in combination with the CLAG-M chemotherapy regimen for the treatment of AML. Actimab-A is one of Actinium's most advanced clinical-stage candidates and may serve as a therapeutic backbone for myeloid malignancies. The Canadian allowance complements a counterpart patent already granted in Japan, with applications pending in the United States and Europe. The Canadian patent issuing from Application No. 3,087,346 titled "Combination Immunotherapy and Chemotherapy for the Treatment of a Hematological Malignancy" will have a patent term running into January 2039.

Iomab-ACT for Gene-Edited Cell-Based Therapies

The allowed application covers Actinium's targeted CD45 conditioning approach used to prepare patients for gene-edited cell-based therapies. Iomab-ACT is designed as a targeted conditioning agent intended to enable adoptive cell therapies. The Canadian allowance builds on a patent already granted in the United States, with additional applications pending in the United States, Europe and China. The Canadian patent issuing from Application No. 3,078,963 titled "Anti-CD45-Based Conditioning Methods and Uses Thereof in Conjunction with Gene-Edited Cell-Based Therapies" will have a patent term running into October 2038.

About Actinium Pharmaceuticals, Inc.

Actinium is a pioneer in targeted radiotherapies designed to improve outcomes for patients with cancer. The company employs a biology-driven approach to develop differentiated radiopharmaceuticals for solid tumors and hematologic malignancies. Its mission is to transform cancer treatment through innovative radioconjugates that maximize therapeutic efficacy while minimizing toxicity to healthy tissue by combining expertise in tumor biology, translational medicine, and radiochemistry. Since inception, Actinium has focused on developing innovative radiotherapies. Its pipeline reflects this strategy across three areas: (1) solid tumor therapeutics including ATNM-400 and Actimab-A with pan-tumor potential; (2) Actimab-A as a therapeutic backbone for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) in collaboration with the National Cancer Institute (NCI); and (3) targeted conditioning agents including Iomab-B for bone marrow transplant and Iomab-ACT for adoptive cell therapy conditioning. ATNM-400 targets a novel antigen distinct from PSMA and has demonstrated preclinical activity across metastatic castration-resistant prostate cancer (mCRPC), non-small cell lung cancer (NSCLC), and breast cancer. Actimab-A has shown improved survival in relapsed/refractory AML with CLAG-M and is advancing toward a Phase 2/3 trial, with additional development ongoing through a CRADA with the NCI. Actinium is also advancing preclinical solid tumor programs and holds ~250 patents and patent applications, including intellectual property related to cyclotron-based production of Ac-225. For more information, please visit www.actiniumpharma.com.

Forward-Looking Statements

This press release may contain projections or other "forward-looking statements" within the meaning of the "safe-harbor" provisions of the private securities litigation reform act of 1995 regarding future events or the future financial performance of the Company which the Company undertakes no obligation to update. These statements, including statements as related to regaining compliance with the rules of the NYSE American and submission of a compliance plan, are based on management's current expectations and are subject to risks and uncertainties that may cause actual results to differ materially from the anticipated or estimated future results, including the risks and uncertainties associated with preliminary study results varying from final results, estimates of potential markets for drugs under development, clinical trials, actions by the FDA and other governmental agencies, regulatory clearances, responses to regulatory matters, the market demand for and acceptance of Actinium's products and services, performance of clinical research organizations and other risks detailed from time to time in Actinium's filings with the Securities and Exchange Commission (the "SEC"), including without limitation its most recent annual report on form 10-K, subsequent quarterly reports on Forms 10-Q and Forms 8-K, each as amended and supplemented from time to time.

Investors: investorrelations@actiniumpharma.com

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SOURCE Actinium Pharmaceuticals, Inc.

Actinium Pharmaceuticals Receives Two Patent Allowances Spanning Its Actimab-A and Iomab-ACT Programs