NCT06520345

The Study of 177Lu-TLX591 Plus SOC Versus SOC Alone in Patients With mCRPC (ProstACT Global)

A Multinational, Multicenter, Prospective, Randomized, Controlled, Open-Label, Phase 3 Study of Lutetium (177Lu) Rosopatamab Tetraxetan in Combination With Standard of Care Versus Standard of Care Alone in Patients With PSMA Positive Metastatic Castration-Resistant Prostate Cancer Previously After Androgen Receptor Pathway Inhibitor Treatment

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 430 (estimated)
• Sponsor: Telix Pharmaceuticals (Innovations) Pty Limited · Industry
• Sex: Male
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this study is to evaluate the efficacy and safety of 177Lu-TLX591 in patients with metastatic castration-resistant prostate cancer who have progressed following treatment with Androgen Receptor Pathway Inhibitor Treatment

Detailed description

The primary objective of the study is to compare radiographic progression-free survival (rPFS) in participants who receive 177Lu-TLX591 with SOC to rPFS in participants who receive SOC only. This study consists of three Parts: * Part 1: Safety and Dosimetry Lead-in, * Part 2: Randomized Treatment Expansion, and * Part 3: Long-term Follow-up The study will commence with a 30-patient safety and dosimetry lead-in (Part 1) and proceed to a randomization treatment expansion in approximately 490 patients (Part 2). Patients in Part 2 will be randomized in a 2:1 ratio to receive either 177Lu-TLX591 + Standard of Care SoC (Group A), or SoC alone (Arm B). SoC in this trial is either: ARPI (enzalutamide or abiraterone) or docetaxel. All patients will be followed in long-term follow-up for at least 5 years from the first therapeutic dose, death, or loss to follow up (Part 3). Only patients that meet PSMA-positivity criteria per Blinded Independent Central Review (BICR) will be eligible for this study.

Conditions

• Metastatic Castration-resistant Prostate Cancer

Interventions

Type	Name	Description
DRUG	177Lu-TLX591	Participants randomized to Group A will receive two 76 mCi (±10%) doses of 177Lu-TLX591 14 days apart
DRUG	Enzalutamide	Enzalutamide (starting dose 160 mg daily) + prednisone / prednisolone (5 mg twice a day) or equivalent.
DRUG	Abiraterone	Abiraterone (starting dose 1,000 mg daily) + prednisone / prednisolone (5 mg once daily for the standard formulation), methylprednisolone (4 mg twice daily for the fine particle formulation) or dexamethasone (1 mg once daily)
DRUG	Docetaxel	Docetaxel: Single agent chemotherapy will consist of docetaxel given at a recommended dose of 75mg/m2 IV every 3 weeks given in combination with oral prednisone / prednisolone (5mg twice a day) or equivalent for up to 10 cycles

Timeline

• Start date: 2024-07-26
• Primary completion: 2027-12-01
• Completion: 2030-12-01
• First posted: 2024-07-25
• Last updated: 2025-07-10

Locations

15 sites across 3 countries: United States, Australia, New Zealand

Regulatory

• FDA-regulated drug study