Treating non-metastatic castrate-resistant prostate cancer (nmCRPC) is about to see some significant changes.
Two different trials, SPARTAN and PROSPER, are reporting top-line results in the treatment of men with nmCRPC. The full results of these trials will be presented today at the Genitourinary Cancer Symposium in San Francisco where Cancer ABCs is in attendance.
PROSPER was a multi-national, randomized, double-blind, Phase III study that enrolled 1,401 men with nmCRPC who were randomized to treatment with either enzalutamide (Xtandi) or a placebo while remaining on the standard of care, ADT.
The primary endpoint for the PROSPER was metastasis-free survival (MFS). Secondary endpoints included progression-free survival (PFS), time to first use of cytotoxic chemotherapy (chemotherapy), and overall survival (OS) among others.
The primary trial results showed men taking Enzalutamide, and ADT decreased their risk of developing distant metastasis or death by 71 percent versus placebo + ADT.
SPARTAN was a multi-national, randomized, double-blind Phase III study that enrolled 1,207 men with nmCRPC who were then randomized to treatment with either apalutamide (ARN-509) (not yet FDA approved) or a placebo and standard ADT.
The primary endpoint for the SPARTAN trial was metastasis-free survival (MFS). Secondary endpoints included time to metastasis, progression-free survival (PFS), time to symptomatic progression, and overall survival (OS) among others.
The trial showed that Apalutamide decreased the risk of a man developing distant metastasis or death by 72 percent versus placebo and ADT.
According to a report, Apalutamide significantly improved the time to metastasis, PFS and time to symptomatic progression versus placebo. They also reported that there was a trend favoring Apalutamide over Xtandi.
We do not know which of these drugs might be superior in the more important area of overall survival.
We do know that both of these drugs will become the new standard of care for men with progressive prostate cancer who become castration-resistant prior to any visible evidence of metastasis.