FDA Clears Path for U.S. Expansion of Telix’s Phase 3 ProstACT Trial in Metastatic Prostate Cancer

Telix announced that the U.S. Food and Drug Administration (FDA) has aligned with the company on advancing the Phase 3 ProstACT Global trial of its investigational radiopharmaceutical therapy, TLX591-Tx (lutetium-177 rosopatamab tetraxetan), into Part 2 in the United States for patients with metastatic castration-resistant prostate cancer (mCRPC).

Following a Type B meeting, the FDA agreed that safety and dosimetry data from the completed Part 1 study are sufficient to support progression to the randomized Phase 3 portion of the trial. The agency also aligned with Telix on the Part 2 clinical protocol, statistical analysis plan, and ongoing safety monitoring framework.

Part 2 will evaluate two doses of TLX591-Tx administered 14 days apart in combination with one of three standard-of-care therapies: abiraterone, enzalutamide, or docetaxel. Recruitment is already underway in countries where regulatory approval has been obtained and is expected to expand to the U.S. pending FDA review of an Investigational New Drug (IND) amendment.

"This is an excellent outcome that enables submission of our IND amendment for initiation of Part 2 of ProstACT Global in the U.S.," said David N. Cade, MD, group chief medical officer at Telix. "Part 2 continues to enroll strongly in regions where recruitment is open."

Neeraj Agarwal, MD, professor of medicine and Presidential Endowed Chair of Cancer Research at Huntsman Cancer Institute, Salt Lake City, and ProstACT Global principal investigator, said the therapy could offer greater flexibility in treatment sequencing.

"TLX591-Tx has the potential to redefine how radiopharmaceutical therapy is integrated into clinical practice," Agarwal said. "Because the complete treatment course is delivered over approximately two weeks, physicians can layer it into an existing regimen with minimal interruption, providing greater flexibility to sequence therapies while preserving future treatment options in patients with metastatic prostate cancer."

The IND amendment for U.S. enrollment will be coordinated with a pending regulatory submission to begin the study in Europe.