摘要First-line systemic therapy with immune checkpoint inhibitors(ICIs)is currently the mainstream treatment for recurrent or metastatic squamous cell carcinoma of the head and neck(R/M SCCHN)that is not amenable to local therapy.However,the optimal treatment after discontinuation of ICIs is still unknown,and no large-scale analysis has been conducted in R/M SCCHN.In this narrative review,we summarize the treatment strategies available to continue ICI therapy using the currently available treatment modalities.After the administration of ICIs,unlike cytotoxic agents,the following responses are observed:durable response,pseudo-progressive disease,hyper-progressive disease,mixed response,immune-related adverse events(irAEs),and improved sensitivity to subsequent chemotherapy.Some patients show a durable response to ICIs and a good prognosis;however,many patients will require salvage therapy.We need to select the subsequent treatment according to the various responses unique to ICIs to obtain a durable response.For instance,there are reports on the effectiveness of reapplication of local therapy for a mixed response,retreatment with ICIs,and off-treatment in responsive cases complicated by irAEs.If a durable response can be maintained with ICI therapy,a long-term prognosis that cannot be obtained with conventional chemotherapy can be achieved.