Outcomes in men with metastatic castration-resistant prostate cancer who received sipuleucel-T and no immediate subsequent therapy: Experience at Dana Farber and in the PROCEED Registry
Prostate Cancer & Prostatic Diseases — Wei XX, Kwak L, Hamid A, et al. | February 11, 2022
In this study, two datasets were used to analyze metastatic castration-resistant prostate cancer (mCRPC) patients managed with sipuleucel-T who did not immediately start subsequent therapy. Findings revealed delayed PSA response in a subset of patients suggesting delayed clinical activity.
Sipuleucel-T has shown survival advantage in phase 3 trials but is employed in few men with mCRPC partially because of low rates of PSA and objective response.
Among 1902 men who underwent treatment for mCRPC in PROCEED (an FDA-requested outcomes registry) and 255 patients treated consecutively with sipuleucel-T at Dana-Farber Cancer Institute (DFCI), 171 and 28 patients were included, respectively.
All patients exhibited increasing PSA before initiating sipuleucel-T and available post-treatment PSA measurements.
Clinical results of interest were: PSA 50 response rate, time to subsequent mCRPC directed therapy, and overall survival (OS).
In the PROCEED cohort, 19.9% demonstrated PSA 50 response at a median of 5.5 months (IQR: 3.9–9.5) since the last sipuleucel-T infusion; median time to subsequent mCRPC directed therapy and median OS were 10 months (95% CI: 9–11) and 49 months (95% CI: 43–NR), respectively.
In the DFCI cohort, 14.3% demonstrated PSA 50 response at a median of 6.3 months (IQR: 4.7–7.0); median time to subsequent mCRPC directed therapy and median OS were 9 months (95% CI: 9–11) and 60 months (95% CI: 51–74), respectively.