The E3805 trial evaluated the efficacy of adding docetaxel to androgen-deprivation therapy (ADT) in men with metastatic hormone-sensitive prostate cancer. A total of 790 patients were randomized to receive either ADT alone or ADT plus docetaxel (75 mg/m² every 3 weeks for six cycles). The primary endpoint was overall survival, with a median of 57.6 months in the combination group versus 44.0 months in the ADT-alone group (hazard ratio 0.61; 95% CI 0.47–0.80; P<0.001). The median time to progression was also significantly longer in the combination group (20.2 months vs. 11.7 months). The combination therapy also resulted in a higher rate of PSA levels below 0.2 ng/mL at 12 months (27.7% vs. 16.8%). Adverse events were generally mild, with a low incidence of grade 3 or 4 febrile neutropenia and infections. The study showed that six cycles of docetaxel at the start of ADT significantly improved overall survival compared to ADT alone. The results were consistent across subgroups, with the greatest benefit observed in patients with high-volume disease. The study was funded by the National Cancer Institute and others. The findings support the use of early docetaxel in combination with ADT for metastatic hormone-sensitive prostate cancer.The E3805 trial evaluated the efficacy of adding docetaxel to androgen-deprivation therapy (ADT) in men with metastatic hormone-sensitive prostate cancer. A total of 790 patients were randomized to receive either ADT alone or ADT plus docetaxel (75 mg/m² every 3 weeks for six cycles). The primary endpoint was overall survival, with a median of 57.6 months in the combination group versus 44.0 months in the ADT-alone group (hazard ratio 0.61; 95% CI 0.47–0.80; P<0.001). The median time to progression was also significantly longer in the combination group (20.2 months vs. 11.7 months). The combination therapy also resulted in a higher rate of PSA levels below 0.2 ng/mL at 12 months (27.7% vs. 16.8%). Adverse events were generally mild, with a low incidence of grade 3 or 4 febrile neutropenia and infections. The study showed that six cycles of docetaxel at the start of ADT significantly improved overall survival compared to ADT alone. The results were consistent across subgroups, with the greatest benefit observed in patients with high-volume disease. The study was funded by the National Cancer Institute and others. The findings support the use of early docetaxel in combination with ADT for metastatic hormone-sensitive prostate cancer.