Actinium Pharmaceuticals Strengthens Actimab-A Patent Portfolio and Manufacturing Capacity Ahead of Key Clinical Milestones

Actinium Pharmaceuticals, Inc. (NYSE American: ATNM), a leader in targeted radiotherapies, revealed important developments in its Actimab-A program on August 14, 2026. These include newly granted patents that broaden the intellectual property (IP) protection for Actimab-A, expansion of manufacturing capacity, and an update on its NYSE American listing status.

The company’s IP portfolio for Actimab-A now encompasses patents covering its manufacture and therapeutic use both as a monotherapy and in combination with other agents. Actimab-A targets myeloid hematological malignancies such as acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), as well as solid tumors by focusing on tumor-resident myeloid-derived suppressor cells (MDSCs).

In the past twelve months, Actinium secured two U.S. patents related to Actimab-A’s targeting of MDSCs for solid tumor treatment. Patent US 12,491,274 covers treatment of sarcoma and expires on October 15, 2043. Patent US 12,539,340 addresses treatment of solid tumors generally, including use alone or with checkpoint inhibitors, expiring October 31, 2043. These patents extend Actinium’s anti-CD33 franchise beyond hematologic cancers by targeting the immunosuppressive myeloid cells within the tumor microenvironment. Corresponding patent applications remain pending in the United States, Canada, and Europe.

For low peripheral blast AML treatment, U.S. patent US 12,410,249 was issued with protection through October 12, 2039. A Canadian application (3,022,802) is in pre-grant status with a term to May 25, 2037. Additional patents in this family have been granted in the U.S. and Japan, with further applications pending in the U.S. and Europe.

Actinium also advanced combination therapies involving Actimab-A. A Canadian application (3,059,752) covering Actimab-A combined with venetoclax (a BCL-2 inhibitor) for AML entered pre-grant status, with a term to April 26, 2038. Related patents have been issued in the U.S. and Mexico, with pending applications in the U.S., Europe, Japan, and China. Another Canadian application (3,087,346) for Actimab-A combined with CLAG-M chemotherapy in AML was allowed, expiring January 8, 2039, with a counterpart patent already issued in Japan and pending applications in the U.S., Europe, and Japan.

To support the clinical development of Actimab-A, Actinium amended its Investigational New Drug (IND) application to include an additional manufacturer. This new manufacturing partner will supply clinical studies conducted under the company’s Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute (NCI), as well as other company-sponsored trials. The expanded manufacturing capacity aims to provide supply flexibility as Actimab-A progresses into broader studies across hematologic malignancies and solid tumors, with key clinical milestones anticipated from the second half of 2026 through 2027.

Regarding its stock exchange status, Actinium announced that NYSE Regulation accepted the company’s compliance plan submitted on June 18, 2026, to regain adherence to NYSE American continued listing standards. The company was granted the maximum plan period under Section 1009 of the NYSE American Company Guide, extending through November 27, 2027. During this period, Actinium’s common stock will continue to trade on the NYSE American under the ticker symbol ATNM, contingent on compliance with the plan and other listing requirements.

Actinium remains currently non-compliant with Sections 1003(a)(ii) and 1003(a)(iii) of the NYSE American Company Guide but benefits from the extension to maintain its listing while working toward full compliance.

Founded as a pioneer in targeted radiotherapies, Actinium focuses on developing radioconjugates that maximize therapeutic efficacy while minimizing toxicity to healthy tissue. Its pipeline includes solid tumor therapeutics such as ATNM-400 and Actimab-A, the latter being developed in collaboration with the NCI for AML and MDS. The company also advances targeted conditioning agents like Iomab-B and Iomab-ACT for bone marrow transplant and cell and gene therapy conditioning. Actinium holds approximately 250 patents and applications, including those related to cyclotron-based production of Actinium-225.

This announcement contains forward-looking statements subject to risks and uncertainties, including those related to patent issuance, clinical trial outcomes, manufacturing capacity, regulatory approvals, and market acceptance. Actual results may differ materially from expectations as detailed in Actinium’s SEC filings.