A randomized controlled phase III trial on continued or paused PD-1 pathway blockade for patients with advanced renal cell carcinoma (JCOG1905, STOP study): a study protocol.

Immune checkpoint blockades (ICBs), particularly PD-1 pathway blockades, have significantly improved outcomes in advanced renal cell carcinoma (RCC). However, long-term ICB therapy imposes substantial financial and toxicity burdens. Retrospective data suggest that treatment responses plateau around 24 weeks, and some patients maintain disease control even after ICB pause. We initiated a multi-institutional, open-label, randomized controlled trial to confirm the non-inferiority of pausing PD-1 pathway blockade to its continuous administration in patients with advanced clear cell RCC without disease progression. The primary endpoint is overall survival and the secondary endpoint includes time to failure of strategy, progression-free survival, and adverse events. Conducted by the Urologic Oncology Study Group of the Japan Clinical Oncology Group (JCOG), this phase III trial was approved by Certified Review Board in February 2020, with patient enrollment beginning in July 2020. The trial is registered in the Japan Registry for Clinical Trials (JCOG1905; jRCT1031200071).