PR Newswire·Nov 12, 2026, 8:00 AM ET

Actinium Pharmaceuticals to Host KOL Webinar on ATNM-400, a First-in-Class HER3-Targeted Alpha Radiotherapy

Actinium Pharmaceuticals will host a KOL webinar on December 1, 2026, at 8:00 a.m. ET featuring Michael J. Morris, MD, to discuss unmet needs in metastatic castration-resistant prostate cancer (mCRPC) & the potential of ATNM-400.
The event will review first-in-human Phase 1 findings for ATNM-400 from the HERACT-PRO-1 trial, noting tumor uptake through Day 7 with no dose-limiting toxicities in the initial cohort at 1.0 µCi/kg.
Management will discuss dose escalation to 1.5 µCi/kg & detail the RADIANZ imaging study designed to validate the pan-tumor potential of ATNM-400.
ATNM-400 is an investigational HER3-targeted Actinium-225 antibody radioconjugate intended for patients with low or negative PSMA expression or those progressing after PSMA-directed therapies.
The webinar will cover HER3's role in tumor progression, the rationale for alpha radiotherapy targeting, & clinical plans for ATNM-400 in prostate cancer & other solid tumors including lung, breast, colorectal, & ovarian cancers.
A live question-and-answer session will follow the presentations, with a replay available on Actinium's website post-event.