I-131-1095 Radioligand Plus Enzalutamide vs Enzalutamide for mCRPC That Progressed During Abiraterone (ARROW).

This phase 2 clinical trial (conducted in the United States and Canada) enrolled chemotherapy-naïve men whose PSMA-positive (as shown by piflufolastat F18 imaging) metastatic prostate cancer had progressed during treatment with abiraterone. The participants were stratified by risk factors at Screening and then randomized 2:1 either to receive PSMA radioligand therapy (up to four 8-week cycles of I-131-1095) plus standard treatment with enzalutamide or to receive standard treatment with enzalutamide as monotherapy. The prostate-specific antigen (PSA) levels and radiographic response or progression (RECIST v1.1 criteria for soft tissue and PCWG3 criteria for bone) were then monitored for up to 53 weeks of randomized treatment. The primary outcome measure was PSA response rate (percentage of participants with a confirmed ≥50% decrease in serum PSA). Other outcome measures included percentage of participants with partial or complete response (radiographic), duration of response, time to progression (PSA or radiographic), time to next treatment for prostate cancer, and overall survival.