Actinium Pharmac Stock Price, News & Analysis

Actinium Pharmaceuticals (NYSE: ATNM) presented preclinical data on ATNM-400, a first-in-class Ac-225 antibody radioconjugate targeting a non-PSMA antigen, at the 32nd Annual Prostate Cancer Foundation Scientific Retreat on Oct 24, 2025. ATNM-400 showed superior tumor control and prolonged survival versus enzalutamide, 177Lu-PSMA-617 and 225Ac-PSMA-617 in 22Rv1 and other models, including ~5× longer tumor control and ~2× longer overall survival versus 177Lu-PSMA-617. Combination with enzalutamide produced complete regressions in 40% of animals. Data support PSMA-independent activity and potential use as monotherapy, combination, or sequential therapy.

Actinium Pharmaceuticals (NYSE: ATNM) announced that first-ever preclinical data for ATNM-400, a first-in-class Actinium-225 antibody radioconjugate, will be presented at the AACR-NCI-EORTC conference Oct 22–26, 2025.

Preclinical findings reportedly show potent anti-tumor activity in EGFR-mutant NSCLC models, overcoming resistance to osimertinib and showing synergy with osimertinib and with enzalutamide in prostate models; animal data included 40% complete tumor regressions in a prostate setting. The poster is scheduled for Oct 25, 2025, and the abstract will be available online Oct 22, 2025 at 12:00 PM ET.

Actinium (NYSE: ATNM) announced that preclinical data for ATNM-400, a first-in-class Ac-225 antibody radioconjugate, will be presented at the 32nd Annual Prostate Cancer Foundation Scientific Retreat on October 23, 2025. The poster highlights durable anti-tumor activity in metastatic castration-resistant prostate cancer models, including activity in tumors resistant to enzalutamide and 177Lu-PSMA-617, and reports superior efficacy versus 225Ac-PSMA-617.

The release states ATNM-400 targets a distinct, non-PSMA antigen that is overexpressed after ARPI therapy, showed synergy with enzalutamide, and improved overall survival in preclinical models. The poster will be viewable online via the company investor relations page after the retreat.

Actinium Pharmaceuticals (NYSE AMERICAN: ATNM) has presented promising preclinical data for ATNM-400, its novel targeted radiotherapy for prostate cancer, at the 4th Annual Targeted Radiopharmaceuticals Summit. The therapy demonstrated superior efficacy compared to Pluvicto® and showed effectiveness in treatment-resistant cases.

Key findings include tumor-specific uptake lasting up to 216 hours, significant survival improvements versus Pluvicto®, and effectiveness against Pluvicto®-resistant tumors. Notably, when combined with enzalutamide (Xtandi®), ATNM-400 achieved complete cures in 40% of prostate cancer tumor-bearing animals. The company expects additional data in the second half of 2025.

Actinium Pharmaceuticals (NYSE: ATNM) presented expanded preclinical data for ATNM-400, their novel prostate cancer treatment candidate, at the SNMMI Annual Meeting. ATNM-400, which uses the alpha-particle emitter Actinium-225, demonstrated superior efficacy compared to both Xtandi (enzalutamide) and PSMA-targeted radiotherapies including Pluvicto. The data showed ATNM-400's ability to overcome resistance to both treatments, with its target being directly implicated in disease progression unlike PSMA. ATNM-400 showed consistent tumor uptake, rapid clearance, and superior prostate cancer cell killing compared to existing treatments. The drug exhibited potent killing of Xtandi-resistant cells and showed better anti-tumor efficacy both as monotherapy and in combination with Xtandi. Notably, ATNM-400 was more potent than both Pluvicto and Ac-225-PSMA-617 in prostate cancer models, positioning it as a potential transformational therapy for prostate cancer treatment.

Actinium Pharmaceuticals (NYSE: ATNM) has enrolled its first patient in a groundbreaking trial of Iomab-ACT, a targeted radiotherapy conditioning agent, with commercial CAR-T therapy at the University of Texas Southwestern Medical Center. Initial clinical data is expected in H2 2025. The trial aims to replace traditional chemotherapy conditioning agents with Iomab-ACT to reduce serious CAR-T related toxicities. The technology targets CD45, a cell surface marker on immune cells, and has shown promising results in previous trials with zero cases of ICANS and minimal CRS. This development could significantly impact the CAR-T therapy market, which generated $4 billion in sales in 2024 and is projected to reach $12 billion by 2030. The addressable market includes approximately 150,000 patients annually across approved CAR-T therapy indications.

Actinium Pharmaceuticals (NYSE: ATNM) has presented promising preclinical results for ATNM-400, a novel targeted radiotherapy for prostate cancer, at the AACR Annual Meeting. The data shows ATNM-400 outperforms Pluvicto, achieving 99.8% tumor growth inhibition with a single 40 µCi/kg dose.

Unlike Pluvicto and most prostate cancer radiotherapies that target PSMA, ATNM-400 is a first-in-class treatment targeting a distinct non-PSMA receptor that remains highly expressed even after Pluvicto treatment. The therapy utilizes Actinium-225, a more potent alpha-particle emitter than Lutetitium-177, causing irreversible DNA breaks with potentially fewer off-target effects.

Key findings demonstrate ATNM-400's efficacy in Pluvicto-resistant tumors, rapid internalization, sustained tumor uptake, and efficient clearance from essential organs. The treatment was well-tolerated with no apparent toxicities at both tested dose levels.

Actinium Pharmaceuticals (NYSE: ATNM) presented data at the AACR Annual Meeting showcasing Actimab-A's mutation agnostic antileukemic effects in AML treatment. The preclinical studies demonstrated significant efficacy when combining Actimab-A with standard AML therapies against multiple mutations (FLT3, NPM1, KMT2A, and TP53).

Actimab-A, the only CD33-targeted radiotherapy using Actinium-225 isotope for AML treatment, showed enhanced tumor growth inhibition and prolonged survival when combined with various therapies including menin inhibitor revumenib, FLT3 inhibitor gilteritinib, and hypomethylating agent azacitidine.

The company is advancing multiple clinical trials, including a Phase 2/3 trial combining Actimab-A with CLAG-M in relapsed/refractory AML and another study with Venetoclax and ASTX-727 in frontline AML under an NCI CRADA. The addressable market spans over 100,000 patients in the U.S. and EU5.

Actinium Pharmaceuticals (NYSE: ATNM) has unveiled ATNM-400, a groundbreaking non-PSMA targeting radiotherapy for prostate cancer using Actinium-225. Initial preclinical data showed remarkable results with 99.8% tumor growth inhibition at 40 µCi/kg and 68.5% at 20 µCi/kg from a single dose.

The therapy demonstrated selective tumor accumulation for up to 144 hours with minimal uptake in healthy tissues. ATNM-400 differentiates itself from Novartis's Pluvicto by targeting a different marker than PSMA and utilizing the more potent alpha-particle emitter Ac-225, potentially resulting in fewer off-target effects.

The company will present initial data at the AACR Annual Meeting (April 25-30, 2025), including results from Pluvicto-resistant prostate cancer models. The presentation will showcase findings from in vitro and in vivo studies, biodistribution imaging, and efficacy analyses at various dose levels.