(UroToday.com)Cisplatin-based chemotherapy is associated with improved responses and more durable outcomes than carboplatin in mUC, though the mechanisms for this are poorly characterized. An exploratory subset analysis of the IMvigor130 trial suggested that the addition of atezolizumab to cisplatin-based chemotherapy had more efficacy (hazard ratio for overall survival 0.73 (0.54 – 0.98) with cisplatin versus 0.91 (0.74-1.10) with carboplatin in cisplatin-treated patients rather than carboplatin treated patients. Dr. Galsky and colleagues hypothesized that perhaps cisplatin is associated with more favorable immunomodulatory effects that predispose tumors to greater response with immune checkpoint blockade.