Dr. Bradley on Impact of SPARTAN and PROSPER in Nonmetastatic CRPC

Deborah A. Bradley, MD, medical oncologist, Levine Cancer Institute, discusses the impact of the recently published SPARTAN and PROSPER trials in nonmetastatic castration-resistant prostate cancer (CRPC).

When enzalutamide (Xtandi) and abiraterone acetate (Zytiga) were shown to improve overall survival in the metastatic setting, researchers hypothesized that if patients with metastases benefit, so should patients without metastases. However, there were never data to support this until the phase III SPARTAN and PROSPER trials. These studies had very similar designs and looked at 2 agents, enzalutamide and apalutamide (Erleada). Primary endpoints in both trials were metastasis-free survival, and both agents significantly prolonged this endpoint. This benefit was seen across all subgroups, Bradley adds.

These findings led to the FDA approval of apalutamide and enzalutamide in February 2018 and July 2018, respectively. Bradley concludes that not only is it important to have 2 treatment options in this space, but also 2 clinical trials to prove their efficacy.