Telix and FDA align on ProstACT Global Phase 3 protocol, IND amendment pending

Telix Pharmaceuticals announced on July 2, 2026 that it held a Type B meeting with the U.S. Food and Drug Administration to review the Part 1 safety and dosimetry data and Part 2 protocol design of the ProstACT Global Phase 3 trial of its therapeutic candidate TLX591-Tx (lutetium-177 (177Lu) rosopatamab tetraxetan) in metastatic castration resistant prostate cancer.¹

According to the company, the FDA has confirmed that the safety data from Part 1 of the study is sufficient to enable progression of Part 2 of ProstACT Global into the U.S., in which TLX591-Tx is administered in two doses, 14 days apart, in combination with one of three randomized standard of care therapies: abiraterone, enzalutamide or docetaxel.¹ Telix also said the FDA and Telix achieved alignment on the Part 2 clinical trial protocol, statistical analysis plan, and ongoing safety monitoring plan.¹

Importantly, initiation of Part 2 in the U.S. remains subject to the FDA's review of an Investigational New Drug (IND) amendment.¹ Telix added that the IND amendment will also be aligned with a pending regulatory submission to initiate the ProstACT Global study in Europe.¹

The trial design calls for an international, multicenter trial in two parts: Part 1, safety and dosimetry lead-in with 36 patients (complete); and Part 2, 2:1 randomized global expansion with an overall target enrollment of approximately 490 patients.¹ Enrollment continues outside the U.S., as Part 2 (randomized cohort) continues to recruit in jurisdictions where the study has regulatory approval.¹ Specifically, Part 2 is enrolling in Australia, New Zealand, Canada, Türkiye, and the United Kingdom, and has also received regulatory approval to commence in China, Singapore and South Korea.¹