Phase 3, open-label, randomized study of PF-06821497 combined with enzalutamide compared with enzalutamide or docetaxel for the treatment of participants with metastatic castration resistant prostate cancer previously treated with abiraterone acetate.

A clinical trial is testing whether adding an experimental drug called PF-06821497 to the standard therapy enzalutamide can delay cancer progression in men with metastatic castration-resistant prostate cancer who have already stopped responding to abiraterone acetate. This matters because once abiraterone stops working, treatment options are limited. Patients typically move to another hormone therapy or chemotherapy, but responses are often short-lived. The trial directly compares the combination against the physician’s choice of enzalutamide alone or the chemotherapy drug docetaxel, asking whether the new pairing buys patients more time before their tumours grow. If the combination proves effective, it could offer a new, chemotherapy-free option for men in this late-stage disease setting. That would change clinical practice by adding a targeted therapy to the sequence of treatments, potentially extending the period during which the cancer remains controlled. The trial is not about curing the disease—it is about giving patients more months of stable, manageable disease before more aggressive treatment is needed.