(UroToday.com) Curative intent therapy in muscle-invasive bladder cancer includes neoadjuvant cisplatin-based chemotherapy followed by radical cystectomy, whereas trimodality bladder preservation therapy (maximal TURBT followed by concurrent chemoradiation) is a standard treatment option for clinically localized muscle-invasive bladder cancer, also with curative intent. While no randomized trials exist, propensity risk-matched cohort analyses suggest similar DSS and OS outcomes between bladder preservation and radical cystectomy.1 The optimal chemoradiation regimen has not yet been defined, although hypofractionated radiotherapy regimens combined with gemcitabine have demonstrated promising efficacy and safety in phase I/II studies. Pembrolizumab has shown activity in muscle-invasive bladder cancer in the neoadjuvant setting and may combine well with trimodality bladder preservation therapy to improve outcomes. At the 2021 ASCO annual meeting, Dr. Arjun Balar and colleagues presented results of their phase 2 trial evaluating the safety and efficacy of pembrolizumab added to trimodality bladder preservation therapy in muscle-invasive bladder cancer.