Immune checkpoint inhibitors have improved the treatment landscape of different tumors and one of the emerging issues is the reintroduction of immunotherapy after discontinuation. Scarce evidence is currently available and different definitions have been used. The case of a patient with pretreated advanced urothelial cancer, who responded to immunotherapy retreatment after long-term benefit from the previous course, is reported. Based on a review of the different clinical scenarios, a definition of immunotherapy retreatment was proposed, as rechallenge or reintroduction, based on the reasons of discontinuation of the previous course. Clinical factors potentially associated with clinical benefit from immunotherapy retreatment are discussed, even though ad hoc studies are needed to assess the efficacy and safety of the different immunotherapy retreatment strategies.
Keywords: discontinuation; immune checkpoint inhibitor; immunotherapy; readministration; rechallenge; reintroduction; retreatment; urothelial carcinoma.
Lay abstract Immunotherapy is an effective treatment option for several types of cancer. It is unclear whether a rechallenge with this treatment could be effective following its discontinuation due to disease progression, treatment toxicity or completion. This is a relevant issue as patients with metastatic cancer have few therapeutic options. Therefore, we share our clinical experience and a literature review about this topic. We report the clinical course of a patient affected by metastatic urothelial cancer whose disease responded to retreatment with immunotherapy after a previous long-term benefit from the same treatment, which was discontinued after 2 years having reached the maximum established treatment duration. We describe the different clinical scenarios of immunotherapy retreatment and factors potentially associated with a benefit from this therapeutic strategy.