#United States #Los Angeles #Actinium Pharmaceuticals #ATNM-400 #SNMMI 2026

Actinium Pharmaceuticals Presents Groundbreaking Data on ATNM-400

Actinium Pharmaceuticals, Inc., a leader in targeted radiotherapies, is making headlines with the presentation of three significant abstracts at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting scheduled for May 30 to June 2, 2026, in Los Angeles, California. These presentations shed light on the promising potential of ATNM-400, an innovative Actinium-225 (225Ac) antibody radioconjugate, specifically focusing on its efficacy against non-small cell lung cancer (NSCLC) and prostate cancer.

Highlights of the Presentations

The recent data shared by Actinium reinforces the unique profile of ATNM-400 and its application across various cancer types:

• - NSCLC Insights: New findings suggest that ATNM-400 exhibits potential efficacy in KRAS-mutated models, marking it as a mutation-agnostic therapy in settings where existing EGFR- and KRAS-targeted agents fall short.
• - Prostate Cancer Developments: Additional data indicates that ATNM-400 may serve as an effective treatment in two key prostate cancer scenarios: PSMA-high and PSMA-low, addressing a significant gap in efficacy observed with PSMA-targeted therapies.
• - Radioconjugate Optimization: Importantly, advancements in radiochemistry techniques, particularly in the optimization of the chelator-to-antibody ratio, have led to improved targeting, internalization, and pharmacokinetics of 225Ac-labeled antibodies, further enhancing the clinical potential of ATNM-400.

Company Remarks

Sandesh Seth, the Chairman and CEO of Actinium, emphasized that the data to be revealed at the SNMMI 2026 will solidify ATNM-400's position as a first-in-class radiotherapy agent with a wide application scope among solid tumors. He stated, "In NSCLC, ATNM-400 can effectively navigate through significant resistance mechanisms associated with both EGFR and KRAS mutations. In prostate cancer, the data underscore its potential even in PSMA-negative contexts, along with promising results in PSMA-high and medium scenarios. As we prepare for clinical studies, we’re focused on maximizing the therapeutic index of ATNM-400 through our advanced radiochemistry capabilities.”

Presentation Details

1. Abstract Title: ATNM-400: A First-in-Class Actinium-225 Antibody Radioconjugate Demonstrating Potent PSMA-Independent Efficacy in Prostate Cancer Models
Session: Oncology Discovery Translational Meet the Author Session
Date & Time: June 2, 2026, 11:30 AM - 12:15 PM PT

2. Abstract Title: ATNM-400: A First-in-Class Actinium-225 Antibody Radioconjugate Demonstrating Durable, Mutation-Agnostic Anti-Tumor Activity in Non-Small Cell Lung Cancer Models
Session: Oncology Discovery Translational Meet the Author Session
Date & Time: June 2, 2026, 11:30 AM - 12:15 PM PT

3. Abstract Title: Optimizing Chelator-to-Antibody Ratio Improves Tumor Targeting and Pharmacokinetics of 225Ac-Labeled Antibodies
Session: MTA05 RPSC/CMIIT POPs and Science Pavilion Mixer
Date & Time: May 31, 2026, 7:30 PM - 8:00 PM PT

About Actinium Pharmaceuticals

Actinium specializes in developing targeted radiopharmaceuticals to enhance patient outcomes in the battle against cancer. With a strong focus on biology-driven strategies, Actinium aims to create advanced treatments that maximize therapeutic efficacy while minimizing harm to healthy tissues. Their ongoing efforts center around solid tumors as well as hematologic malignancies, with initiatives for products like ATNM-400 and Actimab-A, targeting various antigen profiles beyond just PSMA. Actinium also boasts a robust pipeline consisting of novel agents addressing significant oncology challenges. For up-to-date information about Actinium and its innovative contributions, visit Actinium's official website.

This press release contains forward-looking statements concerning Actinium's future developments and is subject to inherent risks associated with medical advancements and market dynamics.