Telix Pharmaceuticals Gains FDA Alignment on ProstACT Global Phase 3 Trial Statistical Framework

A Type B meeting with the FDA has cleared the path for Telix Pharmaceuticals to file an IND amendment advancing Part 2 of the ProstACT Global Phase 3 trial into the United States, a development that sets a defined statistical and safety monitoring framework for one of the more complex radiopharmaceutical therapeutic programs currently in late-stage development.

The FDA confirmed that Part 1 safety and dosimetry data for TLX591-Tx (177Lu rosopatamab tetraxetan) is sufficient to support Part 2 progression. The agency also aligned with Telix on the clinical trial protocol, statistical analysis plan, and ongoing safety monitoring plan for the randomized expansion cohort, in which TLX591-Tx is administered in two doses 14 days apart alongside one of three standard-of-care therapies: abiraterone, enzalutamide, or docetaxel.

For regulatory affairs teams, the meeting outcome is operationally significant. FDA alignment on the statistical analysis plan at this stage reduces the risk of protocol amendments mid-enrollment, a recurring friction point in multinational Phase 3 programs. The IND amendment will also be coordinated with a pending regulatory submission to initiate the study in Europe, creating a dual-jurisdiction filing sequence that QA and regulatory leads will need to track closely against enrollment timelines.

ProstACT Global (NCT06520345) targets patients with progressive metastatic castration-resistant prostate cancer confirmed by 68Ga-PSMA-11 PET imaging following prior ARPI treatment. Part 2 targets approximately 490 patients in a 2:1 randomized design and is currently enrolling in Australia, New Zealand, Canada, and Türkiye. U.S. site initiation remains contingent on FDA review of the IND amendment.

From a manufacturing and compliance standpoint, TLX591-Tx presents a differentiated profile within the PSMA-targeted radioligand therapy class. The agent is hepatically excreted rather than renally cleared, and long-term follow-up data to date has not identified significant acute or delayed kidney toxicity, a distinction relevant to both dosimetry planning and safety monitoring protocol design. Minimal salivary and lacrimal gland uptake also differentiates its adverse-event profile from existing small-molecule PSMA-targeted therapies.

The pending IND amendment submission will serve as the near-term indicator of how efficiently Telix can translate Type B meeting alignment into active U.S. enrollment across the three standard-of-care combination cohorts.

Source: Telix Pharmaceuticals via corporate press release, July 2, 2026.