ATNM-400 / Actinium - LARVOL DELTA

Actinium Presents Data Supporting Paradigm Changing Potential of ATNM-400 in Prostate Cancer Demonstrating Its Superior Efficacy and Improved Survival in Treatment Resistant Tumor Models versus Pluvicto and ARPI Therapy, and Also Enhanced Efficacy in Combination with ARPI Therapy at the 4th Annual Targeted Radiopharmaceuticals Summit (PRNewswire) - "Unlike PSMA-targeted agents that primarily serve as imaging and targeting tools, the ATNM-400 target is directly implicated in tumor progression, survival signaling, and resistance to androgen receptor (AR) pathway inhibitor (ARPI) therapy...The ATNM-400 antibody showed sustained tumor uptake up to 216 hours with rapid clearance from normal tissues; ATNM-400 is more efficacious than Pluvicto (Lu-177-PSMA-617) with potent tumor control; ATNM-400 demonstrated significant in vitro tumor cell killing when used in combination with AR-targeting agents, such as enzalutamide...Actinium highlighted that follow-up continues to further evaluate the durability of ATNM-400's anti-tumor efficacy in prostate cancer with additional data expected in the second half of 2025."

Preclinical • Prostate Cancer

First-in-class Actinium-225 (Ac-225) antibody radioconjugate ATNM-400 exhibits potent anti-tumor activity in preclinical solid tumor models (SNMMI 2025) - "Pluvicto® (lutetium Lu 177 vipivotide tetraxetan) and Lutathera® (lutetium Lu 177 dotatate), both FDA-approved beta-emitting therapies, have demonstrated efficacy in metastatic prostate cancer and gastroenteropancreatic neuroendocrine tumors, respectively, highlighting the potential of TR in addressing unmet clinical needs. ATNM-400 demonstrated robust anti-tumor efficacy in multiple preclinical models of solid tumors, supporting its potential as a novel therapeutic option for patients with limited treatment options or resistant to current targeted therapies. These findings underscore the promise of ATNM-400 for clinical translation and its role in addressing unmet needs in cancer therapy."

Preclinical • Breast Cancer • Endocrine Cancer • Genito-urinary Cancer • Lung Cancer • Neuroendocrine Tumor • Oncology • Pancreatic Cancer • Prostate Cancer • Solid Tumor

First-in-class Actinium-225 (Ac-225) antibody radioconjugate ATNM-400 exhibits potent anti-tumor activity in preclinical solid tumor models (SNMMI 2025) - "Pluvicto® (lutetium Lu 177 vipivotide tetraxetan) and Lutathera® (lutetium Lu 177 dotatate), both FDA-approved beta-emitting therapies, have demonstrated efficacy in metastatic prostate cancer and gastroenteropancreatic neuroendocrine tumors, respectively, highlighting the potential of TR in addressing unmet clinical needs. ATNM-400 demonstrated robust anti-tumor efficacy in multiple preclinical models of solid tumors, supporting its potential as a novel therapeutic option for patients with limited treatment options or resistant to current targeted therapies. These findings underscore the promise of ATNM-400 for clinical translation and its role in addressing unmet needs in cancer therapy."

Preclinical • Breast Cancer • Endocrine Cancer • Genito-urinary Cancer • Lung Cancer • Neuroendocrine Tumor • Oncology • Pancreatic Cancer • Prostate Cancer • Solid Tumor

Actinium Highlights Expanded Data Set for ATNM-400 in Prostate Cancer Demonstrating Superior Efficacy to Enzalutamide and Ability to Overcome Resistance to ARPI Therapy and PSMA-Ac-225/Lu-177 Labelled Radiotherapy at the Society of Nuclear Medicine & Molecular Imaging Annual Meeting (PRNewswire) - "ATNM-400 shows consistent tumor uptake, rapid clearance from the blood and clearance from vital organs including intestines, liver, and kidneys...ATNM-400 exhibited potent killing of all Xtandi resistant prostate cancer cells that remained following treatment with Xtandi, with Xtandi only killing 50% of the resistant prostate cancer cells; ATNM-400 monotherapy and in combination with Xtandi had superior anti-tumor efficacy in vivo compared to Xtandi alone in a prostate cancer model; all treatments were well-tolerated with no change in body weight; ATNM-400 inhibited tumor growth of Xtandi resistant tumors whereas re-treatment with Pluvicto or additional enzalutamide did not....ATNM-400 was more potent than both Pluvicto (177Lu-PSMA-617) and 225Ac-PSMA-617 in prostate cancer cell killing."

Preclinical • Castration-Resistant Prostate Cancer • Prostate Cancer

Actinium Presents Data Showing ATNM-400 is More Efficacious than Pluvicto and is Highly Efficacious after Pluvicto Resistance in Prostate Cancer Tumor Models at the American Association for Cancer Research Annual Meeting (PRNewswire) - "In mice bearing Pluvicto-failed tumors, ATNM-400 was administered on day 14 following Pluvicto treatment, demonstrating robust antitumor activity and tumor growth inhibition in Pluvicto- resistant tumor models.; Expression of the target receptor for ATNM-400 persists following Pluvicto therapy and ATNM-400 demonstrates sustained tumor control after Pluvicto stops working; ATNM-400 demonstrated greater efficacy than Pluvicto in prostate cancer models with 99.8% tumor growth inhibition achieved with a single 40 µCi/kg dose of ATNM-400 supporting its potential to be offered as an alternative option; ATNM-400 internalizes rapidly, exhibiting potent cytotoxicity and prostate cancer cell killing via double strand DNA breaks that are produced by the Ac-225 alpha-particle emitting radionuclide payload of ATNM-400...'we look forward to validating the potential of this exciting radiotherapy candidate as we advance its development with additional data expected later this year.'"

Preclinical • Castration-Resistant Prostate Cancer • Prostate Cancer

ATNM-400 is a novel Actinium-225 antibody radioconjugate with strong efficacy in preclinical models of prostate cancer (AACR 2025) - "ATNM-400 showed strong anti-tumor efficacy and a favorable safety profile in preclinical PCa models. These results highlight ATNM-400's potential as a transformative therapeutic option for PCa patients with unmet clinical needs."

Preclinical • Castration-Resistant Prostate Cancer • Genito-urinary Cancer • Oncology • Prostate Cancer • Solid Tumor • FOLH1

Actinium Pharmaceuticals Provides Business Update After Presentation at Trump Mar-A-Lago Club Announcing Novel Non-PSMA Prostate Cancer Radiotherapy ATNM-400 and Outlining Revitalized Clinical Pipeline with 2025 Corporate Objectives (PRNewswire) - "Actinium Pharmaceuticals...provided a business update detailing recent achievements and anticipated milestones from its revitalized and expanding clinical pipeline. The update featured the unveiling of ATNM-400, Actinium's new Actinium-225 (Ac-225) solid tumor program, which is a novel, non-PSMA targeting, first-in-class radiotherapy for prostate cancer. Initial preclinical data from ATNM-400 will be presented at AACR on April 27, 2025....Pipeline Expansion into Prostate Cancer with ATNM-400, a first-in-class, non-PSMA targeting Ac-225 radiotherapy."

Preclinical • Prostate Cancer