Actinium Pharmaceuticals Inc (NYSE American:ATNM), a developer of targeted radiotherapies, announced on Monday that the first-ever preclinical data from its ATNM-400 programme in non-small cell lung cancer (NSCLC) has been accepted for presentation at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics being held from 22-26 October 2025 at the Hynes Convention Center in Boston, Massachusetts.

The company says that ATNM-400 is a highly innovative, first-in-class, Actinium-225 (Ac-225) antibody radioconjugate with preclinical data in both prostate cancer and NSCLC. Together, these two indications represent more than 500,000 new cases annually in the United States alone.

According to Actinium, preclinical data to be presented at the AACR-NCI-EORTC conference demonstrate that ATNM-400 exerts potent anti-tumour activity in EGFR-mutant NSCLC models and is capable of overcoming resistance to osimertinib, and is furthermore synergistic in combination osimertinib. This represents a potential breakthrough for patients with relapsed or refractory EGFR-mutant NSCLC, one of the most urgent areas of unmet need in oncology.

In the multicentre, single-arm Phase 2 trial, Sampath et al. (AstraZeneca & UT Southwestern Harold C. Simmons Comprehensive Cancer Center) reported a median progression-free survival (PFS) of 32.3 months. This reflects a notable 12.3-month improvement over the 20.0-month median PFS observed with osimertinib monotherapy, as reported by Watanabe et al. in a real-world clinical setting.