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Actinium Pharmaceuticals, Inc. Announces Compelling Pan-Tumor Data for ATNM-400 Demonstrating Broad Efficacy Across Prostate, Lung, and Breast Cancer Models at the 2026 American Association of Cancer Research Annual Meeting
Actinium Pharmaceuticals, Inc. (NYSE AMERICAN: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, today announced preclinical results for ATNM-400 across prostate, lung, and breast cancer models presented at the American Association for Cancer Research (AACR) Annual Meeting in San Diego, CA. ATNM-400 is a novel, first-in-class targeted radiotherapy utilizing the Actinium-225 (Ac-225) radioisotope that targets a non-PSMA membrane antigen overexpressed in adv
About this update from Actinium Pharmaceuticals, Inc. (delaware)
[{"type":"list","items":[{"val":[{"type":"text","content":"ATNM-400 demonstrates pan-tumor activity across prostate, lung, and breast cancer models, supporting multi-indication development potential","length":139,"tagName":"p"}]},{"val":[{"type":"text","content":"In prostate cancer, ATNM-400 demonstrates efficacy across both high PSMA-expressing and, importantly, low PSMA-expressing prostate cancer models, unlike many PSMA-targeted radioligand therapies that work only in PSMA-high settings","length":230,"tagName":"p"}]},{"val":[{"type":"text","content":"In EGFR-mutant non-small cell lung cancer, ATNM-400 demonstrates greater tumor growth inhibition than osimertinib (a tyrosine kinase inhibitor) plus chemotherapy and outperforms the approved Trop-2 ADC Dato-DXd (DATROWAY®), the EGFR-cMET bispecific antibody amivantamab (RYBREVANT®) and the experimental EGFR-HER3 ADC izalontamab brengitecan, supporting potential use across first-, second-, and third-line treatment settings","length":425,"tagName":"p"}]},{"val":[{"type":"text","content":"In breast cancer, new head-to-head data shows ATNM-400 achieves efficacy comparable to the approved HER2-ADC trastuzumab deruxtecan (ENHERTU®) in trastuzumab-resistant models, with durable tumor control observed after treatment discontinuation - extending the Company's prior SABCS 2025 data and supporting potential for less frequent dosing of ATNM-400 compared to ADCs","length":374,"tagName":"p"}]},{"val":[{"type":"text","content":"ATNM-400 is well tolerated, with no in vivo toxicities observed at efficacious doses, providing a favorable therapeutic index that supports monotherapy and combination development","length":179,"tagName":"p"}]}],"tagName":"ul","bulletedList":true,"length":1347,"olType":false},{"type":"text","content":"NEW YORK, April 22, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE AMERICAN: ATNM) (Actinium or the Company), a pioneer in the development of targeted radiotherapies, today announced preclinical results for ATNM-400 across prostate, lung, and breast cancer models presented at the American Association for Cancer Research (AACR) Annual Meeting in San Diego, CA. ATNM-400 is a novel, first-in-class targeted radiotherapy utilizing the Actinium-225 (Ac-225) radioisotope that targets a non-PSMA membrane antigen overexpressed in advanced and therapy-refractory solid tumors across multiple onco...