Telix Secures FDA Nod to Expand ProstACT Phase 3 Prostate Cancer Trial

FDA Clears Path for U.S. Expansion of ProstACT Phase 3 Trial

Telix Pharmaceuticals (ASX:TLX) has secured a crucial regulatory green light from the U.S. Food and Drug Administration (FDA) to advance Part 2 of its ProstACT Global Phase 3 trial evaluating TLX591-Tx in metastatic castration-resistant prostate cancer (mCRPC). The FDA's agreement on the clinical protocol, statistical analysis plan, and safety monitoring framework marks a significant milestone, enabling Telix to submit an Investigational New Drug (IND) amendment to initiate U.S. enrolment.

Part 2 of ProstACT Global is a randomized cohort study where TLX591-Tx, a lutetium-177 radiopharmaceutical, will be administered alongside one of three standard-of-care therapies: abiraterone, enzalutamide, or docetaxel. The study design calls for two doses spaced 14 days apart, aiming to integrate TLX591-Tx seamlessly with existing treatment regimens.

International Recruitment and Trial Framework

While awaiting FDA approval of the IND amendment, Part 2 continues to recruit patients in countries with existing regulatory clearances, including Australia, New Zealand, Canada, Türkiye, the United Kingdom, China, Singapore, and South Korea. The trial plans to enrol approximately 490 patients globally, focusing on those with progressive mCRPC confirmed via PSMA PET imaging.

Telix’s Group Chief Medical Officer, Dr David N. Cade, emphasised the importance of the FDA alignment, describing it as an “excellent outcome” that supports ongoing international enrolment and the planned U.S. expansion. The consistency in trial execution across jurisdictions is expected to streamline data collection and regulatory submissions.

Therapeutic Differentiation and Safety Profile

TLX591-Tx differentiates itself from other PSMA-targeted radioligand therapies through its antibody-based mechanism, which results in hepatic rather than renal excretion. This pharmacological trait reduces the risk of kidney toxicity, a common concern with small molecule PSMA therapies. Additionally, TLX591-Tx exhibits minimal uptake in salivary and lacrimal glands, potentially lowering the incidence of xerostomia and dry eye; side effects frequently reported with competing treatments.

Neeraj Agarwal, principal investigator for ProstACT Global and cancer research chair at Huntsman Cancer Institute, highlighted the therapy’s potential to reshape prostate cancer treatment by offering a rapid, two-week course that integrates flexibly with existing standards of care, preserving future treatment options for patients.

Next Steps and Regulatory Considerations

The FDA’s endorsement of the Part 2 protocol and safety data from Part 1 sets the stage for Telix to file the IND amendment necessary to commence U.S. patient enrolment. This regulatory step is being coordinated alongside a pending submission to initiate the study in Europe, signalling a concerted push to expand ProstACT Global’s footprint.

While the filing does not provide detailed timelines or financial guidance related to this milestone, the advancement aligns with Telix’s broader clinical and commercial strategy, which includes a robust pipeline of radiopharmaceutical candidates and recent capital raises to support growth initiatives.