Standard 1L chemotherapy for advanced or metastatic esophageal squamous cell cancer(ESCC) results in poor OS(median<1year).Camrelizumab provided superior OS versus chemotherapy in heavily pretreated advanced/rucurrent ESCC.PD-1 antibody +chemo showed promisng antitumor activity in 1L advanced or metastatic ESCC.PD-L1 expression by CPS at cutoff≥10 has shown better enrichment for efficacy fo checkpoint inhibitors in ESCC.Recently, two clinical trials on Pembrolizumb have attracted our attention,KEYNOTE-181 and KEYNOTE-590.The median duration of response was 9.3 months in pembrolizumab monotherapy (KEYNOTE-181) ,and 8.3 months in Pembrolizumb plus chemotherapy (KEYNOTE-590). We hypothesis that administration of the PD-1 inhibitor will significantly prolong survival compared to PD-1 inhibitor combined with chemotherapy, when used as maintenance therapy in patients sensitive to PD-1 inhibitors.
The purpose of this study is to evaluate the efficacy and safety of Camrelizumab or Camrelizumab plus chemotherapy in patients with untreated, advanced ESCC with PD-L1 CPS≥10 ,who have been achieved PR and CR after treated with Camrelizumab.