ATNM Overview

New Treatment for Resistant Cancers: Actinium Pharmaceuticals announced promising preclinical data for ATNM-400, an antibody radioconjugate showing anti-tumor activity in hormone-resistant and HER2-resistant breast cancer, as well as efficacy in prostate and non-small cell lung cancers.

Presentation at SABCS: The data will be presented at the 2025 San Antonio Breast Cancer Symposium, highlighting ATNM-400's potential to overcome resistance to standard therapies like tamoxifen and trastuzumab, and its ability to synergize with existing treatments.

Broad Indication Potential: ATNM-400 demonstrates best-in-class efficacy across multiple solid tumors, with significant opportunities in high-value markets, including prostate cancer and NSCLC, where it has shown superior activity compared to leading therapies.

Innovative Mechanism: Utilizing Actinium-225, ATNM-400 targets a disease-driving protein linked to poor prognosis, offering a novel approach that may improve outcomes for patients with difficult-to-treat cancers, addressing significant unmet clinical needs.

ATNM-400 Overview: Actinium Pharmaceuticals' ATNM-400 is a first-in-class antibody radioconjugate targeting a non-PSMA antigen, demonstrating potent anti-tumor activity and prolonged survival in prostate cancer models resistant to standard therapies like enzalutamide and 177Lu-PSMA-617.

Efficacy and Resistance: Preclinical studies show that ATNM-400 outperforms existing treatments, achieving durable tumor control and complete regression in 40% of cases when combined with enzalutamide, highlighting its potential in overcoming treatment resistance.

Clinical Implications: The novel mechanism of ATNM-400 offers a promising alternative for patients with metastatic castration-resistant prostate cancer (mCRPC) who have limited options due to low or absent PSMA expression, addressing a significant unmet clinical need.

Future Directions: Actinium plans to explore ATNM-400's applications beyond prostate cancer, including non-small cell lung cancer (NSCLC), where it has shown potential to overcome resistance to existing therapies, further expanding its therapeutic impact.