FPI-2265 (225Ac-PSMA-I&T) and Olaparib for Patients With Metastatic Castration-Resistant Prostate Cancer (mCRPC)

This study is an open-label, multicenter study designed to investigate the efficacy, safety and tolerability of FPI-2265 (225Ac-PSMA-I\&T) in combination with Olaparib in participants with mCRPC. The study will be conducted in two parts, with Part A enrolling participants who have been previously treated with lutetium-177 (177Lu) vipivotide tetraxetan or other 177Lu-PSMA radioligand therapy (RLT) and Part B enrolling participants who have not been previously treated with lutetium-177 (177Lu) vipivotide tetraxetan or other 177Lu-PSMA radioligand therapy. For each part of the study, a Simon 2-stage design will be used to evaluate two dosing regimens. The purpose of this investigation is to determine the recommended FPI-2265 dose and regimen. Conclusions from this Phase 2 study will be based on safety, tolerability, and anti-tumor activity data. Participants with PSMA-positive mCRPC will be allocated to Arm 1 and Arm 2 in a singular, alternating fashion, until all Stage 1 participants are enrolled into each of the two regimens: Arm 1: Will consist of up to six doses of FPI-2265 every six weeks at Dose A and olaparib twice a day on days 1 to 14 of each cycle. Arm 2: Will consist of up to nine doses of FPI-2265 every four weeks at Dose B and olaparib twice a day on days 1 to 14 of each cycle Participants will be monitored and assessed for efficacy response, disease progression, and adverse events.