Immunotherapy with Sipuleucel-T (APC8015) in patients with metastatic castration-refractory prostate cancer (mCRPC): a systematic review and meta-analysis.

Objective To perform a systematic review and meta-analysis of all randomized controlled trials comparing the efficacy of Sipuleucel-T versus placebo for asymptomatic or minimally symptomatic metastatic castration-refractory prostate cancer (mCRPC). Materials ans Methods Several databases were searched, including MEDLINE, EMBASE, LILACS, and CENTRAL. The endpoints were overall survival (OS), time to progression (TTP) and side effects. We performed a meta-analysis (MA) of the published data. The results are expressed as Hazard Ratio (HR) or Risk Ratio (RR), with their corresponding 95% confidence intervals (CI 95%). Results The final analysis included 3 trials comprising 737 patients. The TTP was similar in patients who received Sipuleucel-T or placebo (fixed effect: HR = 0.89; CI 95% = 0.75 to 1.05; p = 0.16), with no heterogeneity detected on this analysis (Chi2 = 2.14, df = 2 (P = 0.34); I2 = 6%). The results showed a higher overall survival in patients treated with Sipuleucel-T (fixed effect: HR = 0.74; CI 95% = 0.61 to 0.89; p = 0.001; NNT = 3). We found no heterogeneity on this analysis either (Chi2 = 1.46, df = 2 (P = 0.48); I2 = 0%). The incidence of adverse events (grade > 3) was the same in both groups. Conclusion Sipuleucel-T prolongs overall survival in patients with asymptomatic or minimally symptomatic mCRPC.