Actinium Pharmaceuticals Inc. will present early human-study findings for ATNM-400 at the European Association of Nuclear Medicine (EANM) congress in Vienna, offering an initial look at a radiotherapy approach for prostate cancer that targets an antigen other than PSMA.
Actinium lists OP-525 for Session 1111 on Monday, Oct. 19; the session begins at 10:45 a.m. ET (14:45 UTC). It is scheduled in Hall G1 during Session 1111, “Prostate Cancer Therapy II.” The congress runs Oct. 17-21.
The Phase 1 study concerns metastatic castration-resistant prostate cancer (mCRPC). Actinium says the candidate is designed for a broad group that includes patients with low or absent prostate-specific membrane antigen (PSMA) expression, as well as those whose disease does not respond to or progresses after PSMA-directed treatment. The company links its non-PSMA target to tumor survival and treatment resistance.
For the imaging work, researchers use ATNM-400 labeled with Zirconium-89 (Zr-89) in serial positron emission tomography (PET) scans. Actinium says the scans will assess safety and track tumor uptake, distribution and clearance, while dosimetry estimates radiation exposure. The therapeutic candidate is an Actinium-225 (Ac-225) antibody radioconjugate, and the company says the imaging and dose estimates are intended to help inform treatment doses of Ac-225-labeled ATNM-400.
Actinium characterized the early findings as support for further development. Sandesh Seth, the company’s chairman and CEO, called them “an important milestone.” The announcement did not give a patient count, dose levels, adverse-event details, imaging measurements or tumor-response figures, so it contained no numerical clinical outcomes.
The OP-525 presentation on Oct. 19 is the next scheduled update identified by the company.
