Posted: Friday, April 14, 2023
The phase III PROSPER trial reported longer survival rates in men with nonmetastatic castration-resistant prostate cancer who received enzalutamide added to androgen-deprivation therapy. When Maha Hussain, MD, of Robert H. Lurie Comprehensive Cancer Center, Chicago, and colleagues analyzed the 12-month follow-up data from the PROSPER study, they observed a statistically significant correlation between depth of prostate-specific antigen (PSA) decline and improved clinical outcomes in nonmetastatic castration-resistant prostate cancer. These findings were published in The Journal of Urology.
“[The PROSPER study] further underscores the value of PSA as an intermediate biomarker for treatment benefit and risk of disease progression in patients with nonmetastatic castration-resistant prostate cancer,” said Dr. Hussain in a press release.
The PROSPER trial was conducted at 398 study locations across 32 countries. At enrollment, patients with nonmetastatic castration-resistant prostate cancer had to have a PSA level greater than 2 ng/mL and a PSA doubling time of less than 10 months. The initial study results showed longer survival times in patients who received enzalutamide plus androgen-deprivation therapy.
The median metastasis-free survival was 37 months in patients with a PSA decline of 90% or greater, compared with about 22 months in those whose PSA level decreased by less than 50%. The overall survival time was related to enzalutamide response, ranging from 41 months, with less than a 50% decline in PSA value to 54 months with a 90% decline or greater. For men who had a 90% decline or greater and a PSA nadir of 0.2 ng/mL or less, survival time increased to 64 months, with the median survival time not reached.
The researchers believe their findings have implications not only for predicting the outcomes of enzalutamide therapy, but also for personalized treatment of patients with nonmetastatic castration-resistant prostate cancer. In addition, the study authors indicate that further studies are needed to clarify the dynamics of change in PSA levels in response to enzalutamide.
Disclosure: For full disclosures of the study authors, visit www.auajournals.org.