Background: The optimal duration of treatment for metastatic patients who achieve a complete response with immune checkpoint inhibitors is unknown. Methods: The outcome for six metastatic bladder cancer patients who received short course of pembrolizumab is reported. Results: A median number of seven cycles of pembrolizumab was given. After a median follow-up of 38 months, progressive disease was confirmed in three patients. All patients relapsed in lymph nodes and underwent pembrolizumab rechallenge: one achieved a complete response, another a partial response. Conclusion: Our case series paves the way for discontinuation of pembrolizumab in patients who achieve a complete response since three out of six patients remain free of disease after 3-year follow-up. Prospective studies are required to confirm our results.
Keywords: checkpoint inhibitor; immunotherapy; pembrolizumab; short course; urothelial cancer.
The rise of immunotherapy in oncology has provided significant gains in survival of metastatic patients. However, questions persist about the optimal use of immune checkpoint inhibitors. For now, treatment is supposed to be delivered until progression of disease. We report a case series of six patients who received a short course of treatment after achieving a complete response. Three of them remained free of recurrence after a median follow-up of 3 years. Our results suggest that a stop-and-go strategy might be appropriate for some patients, thereby sparing the potential toxicities associated with prolonged exposure.