Actinium Pharmaceuticals highlights Phase 1 prostate cancer trial of ATNM-400 at ESMO 2026
ATNM•Actinium Pharmaceuticals will present its first-in-human Phase 1 study of ATNM-400 in metastatic castration-resistant prostate cancer at ESMO in Madrid, Oct. 23-27, 2026. The study will assess safety to establish a recommended Phase 2 dose and evaluate antitumor activity.
1. Trial presentation
Actinium Pharmaceuticals will present its first-in-human Phase 1 ATNM-400 study at ESMO in Madrid, Oct. 23-27, 2026. The trial evaluates the HER3-targeted radiotherapy in metastatic castration-resistant prostate cancer, including patients with or without prior PSMA-directed treatment.
2. Study details
Initial imaging results presented at EANM showed tumor retention, with encouraging tolerability. The study will assess safety to establish a recommended Phase 2 dose and further evaluate antitumor activity; the prostate cancer trial is the first clinical step in a strategy to expand ATNM-400 into additional solid tumors.
