Scheduled maintenance.

Top Line: For metastatic urothelial carcinoma, first line treatment is platinum-based chemotherapy. 

The Study: Many patients will progress relatively soon after first-line chemo, and pembrolizumab is the preferred second-line option because it improves overall survival compared to second-line chemo. So, why not just plan to give pembro as maintenance therapy? In this randomized phase 2 trial, patients with advanced urothelial cancer that was stable after initial platinum chemo were randomized to either maintenance pembro (termed “switch maintenance”) or placebo. Cross-over to pembro was allowed at the time of progression. An initial question is whether switching to another active regimen as “maintenance” will produce an incremental response. With pembro, the incremental response rate was 23% compared to 10% with placebo. With respect to the primary endpoint, maintenance pembro prolonged progression-free survival from 3 → >5 months. Overall survival data is maturing, but ultimately a strategy of either upfront immunotherapy or chemo with maintenance immunotherapy will be determined by ongoing phase 3 trials.

TBL: Maintenance pembro after platinum-based chemo may improve outcomes compared to pembro at progression. | Galsky, J Clin Oncol 2020