Data from a phase IIb study exploring the safety and tolerability of enzalutamide plus docetaxel in patients with metastatic castration-resistant prostate cancer (mCRPC) show that this combination is safe in these patients, although the majority of patients experience neutropenia (86.4%) and fatigue (77.3%) as treatment-related adverse events. Almost all patients who received combination therapy had decreased serum PSA levels. These findings merit further investigation in a larger cohort of patients.