Experience with sipuleucel-T in metastatic castration-resistant prostate cancer (mCRPC) with visceral spread from PROCEED.

174Background: Trials of approved agents in mCRPC have reported shorter overall survival (OS) in men with visceral metastases (mets). The phase 3 IMPACT trial evaluated sipuleucel-T, an autologous cellular immunotherapy, in mCRPC but excluded visceral mets. PROCEED, a registry of mCRPC patients receiving sipuleucel-T, offers the first description of sipuleucel-T in patients with visceral mets. Methods: PROCEED enrolled men with mCRPC treated with sipuleucel-T biweekly x 3. Dose adjustment for organ dysfunction was unnecessary. Men were followed until death, study withdrawal, or a minimum of 3 years. OS is reported in this post-hoc subgroup analysis. Results: 1902 men received ≥1 sipuleucel-T infusion between 2011-2014. Visceral mets (n = 90) included liver (n=21), lung (n=61), and brain (n=2) involvement. Compared to patients without visceral mets (Table), men with visceral mets had poorer performance status (PS) and higher baseline prostate-specific antigen (PSA). Median OS was 20.5 and 31.2 mo in those ...