Bayer starts Phase I study with novel targeted radionuclide therapy in advanced metastatic prostate cancer

225Ac-PSMA-Trillium is an investigational next-generation PSMA-targeted alpha therapy with potential to treat patients with advanced metastatic prostate cancer

Bayer announced initiation of dosing in a Phase I first-in-human clinical study with 225Ac-PSMA-Trillium a next-generation targeted alpha therapy. The investigational candidate, labeled with actinium-225 and comprising a novel PSMA (prostate-specific membrane antigen) -targeting small molecule with a customized albumin-binding moiety, is designed to improve therapeutic efficacy and reduce side effects in normal organs such as salivary glands. The dose-escalation study (NCT06217822) will evaluate the safety, tolerability and efficacy of 225Ac-PSMA-Trillium in patients with advanced metastatic castration resistant prostate cancer (mCRPC).

“Despite recent advances in the treatment landscape for prostate cancer, there is still a high unmet need for novel precision therapy options to improve outcomes for patients with metastatic castration-resistant prostate cancer,” said Fred Saad, MD, FRCS, Professor and Chairman of Surgery at University of Montreal and Director of Genitourinary Oncology at University of Montreal Hospital Center (CHUM), Canada. “225Ac-PSMA-Trillium is a novel approach, which could provide a new treatment to address this unmet need in mCRPC.”

“Targeted radionuclide therapy is a strategic pillar of precision oncology at Bayer, holding the promise to shift the treatment paradigm for patients, including those whose disease has developed resistance to other treatments,” said Dominik Ruettinger, M.D., Ph.D., Head of Research and Early Development for Oncology at Bayer. “We are excited to announce initiation of the Phase I and dosing of the first patient with 225Ac-PSMA-Trillium. With its unique design, we believe it could offer a meaningful benefit for patients with metastatic prostate cancer, and we look forward to advancing the program through clinical development.”

Prostate cancer is the second most commonly diagnosed cancer in men 1 and a key area of focus at Bayer. Despite significant advances in the last decade, mCRPC remains a deadly disease with a median survival of about 31 months.2 Bayer remains committed to advancing medical innovations for patients across all stages of prostate cancer. The company’s franchise includes two products on the market (Nubeqa™ and Xofigo™) and several compounds in development, including 225Ac-pelgifatamab (BAY 3546828), an actinium-225-labeled PSMA-targeted antibody conjugate, in Phase I.

In April, Bayer introduced 225Ac-PSMA-Trillium during the New Drugs on the Horizon session at the AACR (American Association of Cancer Research) Annual Meeting.3 Along with preclinical in vitro and in vivo characterization, the results were presented for a Phase 0 clinical imaging and dosimetry study conducted in participants with prostate cancer.