$ATNMJun 3, 2026, 8:00 AM ETAI processed
Actinium's ATNM-400 shows preclinical tumor regressions in KRAS/EGFR NSCLC and synergy with approved inhibitors
AI Summary
Actinium presented preclinical SNMMI data showing ATNM-400 produced tumor regressions in KRAS-mutant models and achieved complete tumor cures in an EGFR-mutant mouse model when combined with osimertinib. KRAS inhibitors sotorasib and adagrasib increased ATNM-400's target expression up to ~3.5–3.8x and combinations deepened tumor-cell killing, supporting a mutation-agnostic development strategy given the target is reported in ~98% of NSCLC tumors. These are preclinical cell-line and animal results only, so clinical efficacy and safety in humans remain unproven.
Positives
- ATNM-400 caused tumor regression as monotherapy in KRAS models and complete cures in an EGFR model when combined with osimertinib
- Approved KRAS inhibitors (sotorasib, adagrasib) raised ATNM-400 target expression ~3.5–3.8x and enhanced anti-tumor activity in combinations
- Target antigen is reported as present in ~98% of NSCLC tumors, supporting a potential mutation-agnostic commercial opportunity
Negatives
- Data are preclinical (cell lines and mouse models), not clinical—translation to humans is unknown
- Human safety and tolerability data are not reported; only animal tolerability was described
- No clinical development timeline, regulatory pathway, or planned trials were disclosed