Actinium Pharmaceuticals, Inc.

NEW YORK, Sept. 4, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE American: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, today announced that Sandesh Seth, Chairman and Chief Executive Officer, will present at the H.C. Wainwright 28th Annual Global Investment Conference, being held September 14-16, 2026, in New York, NY. Company management will also be available for one-on-one meetings with investors. Conference Details Event: H.C. Wainwright 28th Annual Global Investment ConferencePresentation Date and Time: Monday, September 14, 2026, 3:00 – 3:30 p.m. ETLocation: New York, NY Registered conference attendees may request a one-on-one meeting with management through their H.C. Wainwright representative. 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 cell and gene 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 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 the timing and outcome of the Company's clinical milestones and data readouts, preliminary study results varying from final results, the scope, validity and enforceability of the Company's intellectual

NEW YORK, Aug. 14, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE American: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, today announced advances across its Actimab-A program, including recently acquired patents adding to a broad suite of IP, and expansion of the Company's manufacturing capacity, as the program approaches clinical milestones from the fourth quarter of 2026 and into 2027. The Company also provided an update on the status of its NYSE American listing. Actiniums holds a broad IP portfolio covering the manufacture of Actimab-A, as well as its use alone and in combination with other therapies in the treatment of myeloid hematological malignancies including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), in addition to solid tumor cancers via targeting of tumor-resident myeloid-derived suppressor cells (MDSCs). Actimab-A patent portfolio activity in the last twelve months: Actimab-A targeting of myeloid-derived suppressor cells (MDSCs) for the treatment of solid tumors: Two United States patents issued — US 12,491,274 for the treatment of sarcoma, expiring 15 October 2043, and US 12,539,340 for the treatment of solid tumors generally, alone or with checkpoint therapy, expiring 31 October 2043. Together they extend the anti-CD33 franchise beyond hematologic malignancy into solid tumors by targeting the immunosuppressive myeloid cells of the tumor microenvironment rather than the tumor cells themselves. Applications remain pending in the United States, Canada and Europe. Actimab-A treatment of low peripheral blast AML: US 12,410,249 issued, with a term to 12 October 2039, and Canadian application 3,022,802 entered pre-grant status, with a term to 25 May 2037. Additional patents in this family have already issued in the United States and Japan; applications remain pending in the United States and Europe. Actimab-A venetoclax (BCL-2 inhibitor) combination therapy for the treatment of AML: Canadian application 3,059,752 entered pre-grant status, with a term to 26 April 2038, covering the use of Actimab-A together with venetoclax in AML. Three patents have already issued in the United States and one in Mexico; applications remain pending in the United States, Europe, Japan and China. Actimab-A CLAG-M combination therapy for the treatment of AML: Canadian application 3,087,346 was allowed, with a term to 8 January 2039. A counterpart patent has already issued in Japan; applications remain pending in the United States, Europe and Japan. Actinium has amended its Investigational New Drug (IND) application to add an additional manufacturer. The additional manufacturer will supply studies conducted under the Company's Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute (NCI), together with additional Company-sponsored studies, which carry clinical milestones expected from the second half of 2026 and throughout 2027. Establishing an additional manufacturing source is intended to expand capacity and supply flexibility as Actimab-A advances into a broader set of studies across hematologic malignancies and solid tumors. NYSE American Listing Update Actinium also announced today that NYSE Regulation has accepted the Company's plan submitted June 18, 2026, to regain compliance with the NYSE American continued listing standards and granted the Company a plan period through Novem

New KRAS-mutant data show ATNM-400 outperformed standard-of-care inhibitors sotorasib and adagrasib as a monotherapy. Treatment with these agents increased expression of the ATNM-400 target greater than 3.5x and enhanced their effect in combination  Additional data in the EGFR-mutant setting demonstrated powerful synergy with osimertinib due to enhanced target expression in treated animals resulting in complete tumor regression in the combination arm  The data with EGFR and KRAS mutations which account for approximately 40-50 percent of all NSCLC cases provide compelling evidence of the potential of ATNM-400 as a monotherapy or in combination with inhibitory agents against these mutations  ATNM-400 is a radioconjgate comprising an antibody coupled to Actinium-225 which causes cell death via double stranded DNA breaks independent of cellular mechanisms and offers broad potential as a mutation agnostic agent in NSCLC where its target is expressed in over 90 percent of tumors with greater expression as resistance emerges NEW YORK, June 3, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE American: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, on June 2, 2026, presented new preclinical data on ATNM-400 in non-small cell lung cancer (NSCLC) at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2026 Annual Meeting in Los Angeles, California. The new KRAS-mutant data, together with a growing body of EGFR-mutant data, demonstrate ATNM-400's activity across the two major mutation driver classes in NSCLC and support a distinct strategic opportunity. ATNM-400 can be developed as a potential mutation-agnostic backbone for the broader NSCLC market, alone or in combination with standard-of-care therapies, rather than as another mutation-specific drug for a narrow subset. NSCLC accounts for roughly 85% of the more than two million lung cancer cases diagnosed globally each year, a market more than twice the size of prostate cancer. It is also highly heterogeneous: no single mutation dominates, so treatments are fragmented across mutation-specific therapies such as EGFR, KRAS, BRAF, ALK and others, each marketed by different companies, each addressing only a molecular subset, and each ultimately limited by acquired resistance. ATNM-400, Actinium's first-in-class Actinium-225 (Ac-225) antibody radioconjugate, is designed to break out of that single-mutation paradigm. Rather than blocking a specific mutant protein, it delivers a high-linear-energy-transfer alpha-particle payload that induces dense, irreversible double-strand DNA breaks and tumor-cell death independent of a tumor's driver mutation or signaling pathway, the mechanistic basis of its mutation-agnostic activity. ATNM-400's target antigen, from previously published immunohistochemistry studies, is present in approximately 98% of NSCLC tumors and highly expressed in approximately 70% of those tumors. It is conserved across EGFR-, KRAS-, and other driver-defined subgroups, and further increased in tumors that have become resistant to EGFR, KRAS, and immune-checkpoint therapies. In new KRAS-mutant studies presented at SNMMI, sotorasib (active ingredient in LUMAKRAS®/Amgen) and adagrasib (active ingredient in KRAZATI®/BMS) increased ATNM-400's target up to 3.5- and 3.8-fold, respectively, and adding ATNM-400 deepened tumor-cell killing beyond either inhibitor alone. These results demonstrate the same target-expression increasing, synergy-enabling biology shown previously with the EGFR inhibitor osimertinib, which produced tumor growth inhibition of 107% when combined with ATNM-400. These combination benefits also broaden ATNM-400's commercial opportunity. The franchises it co

New data demonstrated ATNM-400 remains potently active in prostate cancer cells and tumors resistant to all three approved androgen receptor inhibitors (ARPIs) -enzalutamide (Xtandi®), apalutamide (Erleada®), and darolutamide (Nubeqa®)- directly targeting the point of failure for a high proportion of mCRPC patients   ATNM-400 substantially outperformed apalutamide and darolutamide in an ARPI-resistant tumor model, and in combination with either ARPI it showed durable complete responses, supporting both monotherapy and combination strategies in refractory disease similar to prior data with enzalutamide  ATNM-400 delivered superior tumor control as a single bolus or repeat dose with a consistent safety profile and minimal off-target toxicity across treatment regimens, indicating dosing flexibility and a wide therapeutic window that could de-risk clinical translation. In high PSMA expressing disease, ATNM-400 outperformed 177Lu-PSMA-617 in terms of activity and was similar to 225Ac-PSMA-617. However, as its target is not expressed in the salivary glands, ATNM-400 is not expected to cause xerostomia which is a key limitation of PSMA directed therapies NEW YORK, June 3, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE American: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, on June 2, 2026, presented new data on ATNM-400 in prostate cancer at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2026 Annual Meeting taking place in Los Angeles, California. Androgen receptor pathway inhibitors (ARPIs) such as enzalutamide (Xtandi®, Astellas/Pfizer), apalutamide (Erleada®, Johnson & Johnson), and darolutamide (Nubeqa®, Bayer) are foundational to advanced prostate cancer care, but virtually all patients eventually develop resistance and progress -with up to 50,0001 patients per year exhausting ARPI therapy- creating a large and recurring unmet need. ATNM-400, Actinium's first-in-class Actinium-225 antibody radioconjugate, targets a non-PSMA antigen linked to aggressive prostate cancer biology and delivers a high-energy alpha-particle payload that kills tumor cells through a mechanism independent of PSMA expression and androgen receptor signaling. In preclinical head-to-head studies, this PSMA-independent mechanism allowed ATNM-400 to match or exceed PSMA-targeted radioligand therapies, including 177Lu-PSMA-617 (active ingredient of Pluvicto®, Novartis) and 225Ac-PSMA-617, across PSMA-high, PSMA-low, and PSMA-negative models. _______________________________ 1 Candelieri-Surette D, Lee J, Lynch JA, et al. Epidemiology of Metastatic Castration-Resistant Prostate Cancer in Veterans Nationwide. J Natl Compr Canc Netw. 2025;23(8):307–313. doi:10.6004/jnccn.2025.7032. The new data presented at SNMMI 2026 address three key questions: whether ATNM-400 can overcome ARPI resistance in the mCRPC setting, whether it works as both a single agent and in combination, and how its dosing and safety profile support translation to patients. The data answer each: ATNM-400 remained potent against cells and tumors resistant to all three approved ARPIs, achieved 94% tumor growth inhibition as a single agent and durable complete responses in combination, and maintained a consistent, clean safety profile across both single-b

Proven Chief Medical Officer at several publicly listed and clinical-stage oncology companies with successful track record developing multiple modalities including radiotherapies from preclinical through global approvals across hematologic malignancies and solid tumors Played a leading role in clinical development and worldwide approvals of Erbitux® at Merck KGaA leading to its blockbuster status Led clinical development as CMO of NBE Therapeutics which was acquired by Boehringer Ingelheim for $1.4 billion, and most recently CMO of radiotherapy company Full-Life Technologies Timely key hire with Dr. Heeger's operational rigor and clinical expertise expected to elevate development of Actimab-A, ATNM-400, and Iomab-ACT as Actinium advances toward key data readouts and expanded clinical trials in 2H:2026 NEW YORK, June 1, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE AMERICAN: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, today announced the appointment of Steffen Heeger, MD, MSc, as Chief Medical Officer. Dr. Heeger brings a rare combination of radiotherapy expertise, global oncology drug development leadership, and public-company experience.  Over his career, he has translated multiple programs from IND submission through global clinical approval in the US, EU, and Japan including the blockbuster Erbitux® and led as CMO an oncology company acquired for $1.4 billion.  Most recently Dr. Heeger served as CMO of a clinical-stage radiotherapy company where he advanced into global development, a PSMA program directly relevant to Actinium's ATNM-400 asset. His appointment comes at a pivotal moment as Actinium prepares to advance Actimab-A, ATNM-400, and Iomab-ACT toward key data readouts and expanded clinical trials in the second half of 2026. "Steffen's background is uniquely suited to unlock the value in Actinium's pipeline" said Sandesh Seth, Chairman and Chief Executive Officer of Actinium Pharmaceuticals. "He has successfully taken multiple targeted oncology and radiotherapy programs from the lab into patients, including anti-PSMA programs directly relevant to our ATNM-400 asset, and has deep experience navigating global regulatory pathways with the FDA and international agencies. Steffen brings precisely the combination of deep radiotherapy expertise, global oncology clinical development leadership, regulatory experience, and executional intensity that we need as we advance and expand our pipeline of targeted radiotherapies." "Importantly, Steffen's experience spans both hematologic malignancies and solid tumors, aligning exceptionally well with our strategic focus of building Actinium into a leading targeted radiotherapy company." Mr. Seth added. "His direct experience with alpha-emitting radiotherapies, translational medicine, and global clinical execution will be highly valuable as we progress our clinical programs and pursue new opportunities to unlock the full potential of our platform. Few clinical leaders know radiotherapy development as deeply as Steffen does, and fewer still pair that with the public-company experience and translational oncology track record he brings. W