Camrelizumab and metronomic capecitabine for patients with treatment-refractory solid tumors (McCREST trial)

Plain language summary Immune checkpoint inhibitors (ICIs) such as PD-1 inhibitors have been used to treat gastrointestinal cancer patients in clinical practices. Combination with other drugs can improve the efficacy of ICIs. Metronomic chemotherapy using low dose and high frequency of cytotoxic drugs has multi-targeted anti-tumor effects and can be a potential partner of ICIs. In this study, the authors assess the safety and efficacy of a combination of a PD-1 inhibitor (camrelizumab) and an oral chemotherapy drug (capecitabine with metronomic dose) in patients with metastatic treatment-refractory solid tumors. This is an open-label, single-center, multi-cohort phase Ib trial, which consists of three cohorts, including cohort 1 (HER2 negative gastric or gastric esophageal junction adenocarcinoma), cohort 2 (esophageal squamous cell carcinoma and head and neck squamous cell carcinoma) and cohort 3 (hepato-biliary-pancreatic and non-stomach non-esophagi gastrointestinal carcinoma). All eligible patients will be treated by camrelizumab (200 mg, every 2 weeks) and capecitabine (500 mg, twice a day, per os). The primary end point is the safety profiles of camrelizumab plus metronomic capecitabine according to CTCAE v5.0. The secondary end points are progression free survival, overall survival, objective response rate, disease control rate and duration of response. Planned enrollment is 20 subjects for each cohort. Total duration of this trial is expected to be 2 years.