Description:

This is an open-label, randomized, multicenter study of FPI-2265 (225Ac-PSMA-I&T). The dose optimization Phase 2 part will be investigating the safety, tolerability, and anti-tumor activity of novel dosing regimens of FPI-2265 in participants with PSMA-positive mCRPC who have been previously treated with 177Lu-PSMA-617 or another 177Lu-PSMA radioligand therapy (RLT). The purpose of the dose optimization segment (Phase 2) is to determine the recommended FPI-2265 dose and regimen. Conclusions from Phase 2 will be based on safety, tolerability, and anti-tumor activity. Participants with PSMA positive scans will be randomized (1:1:1) to one of three different dosing arms: Arm 1: Will consist of nine doses of FPI-2265, administered every four weeks at 50 kBq/kg. Arm 2: Will consist of six doses of FPI-2265, administered every six weeks at 75 kBq/kg. Arm 3: Will consist of four doses of FPI-2265, administered every eight weeks at 100 kBq/kg. Participants will be monitored and assessed for efficacy response, disease progression and adverse events.