The Safety and Tolerability of PD-L1 Monoclonal Antibody Plus Lenalidomide in The Treatment of Colorectal Cancer

1. Phase 1 was the dose increasing phase, which was divided into three queues (A, B and C). Each team was included in the group of three people.Cohort B: pd-l1 monoclonal antibody 900mg q3w+ lenalidomide 25mg/d, administration for 21 days/discontinuation for 7 days;Cohort C: pd-l1 monoclonal antibody 20mg/kg q3w+ lenalidomide 25mg/d, administration for 21 days/discontinuation for 7 days.If none of the 3 patients in cohort A in phase 1 showed dose limited toxicity (DLT) within 21 days of their first use, they were enrolled in cohort B, and so on.If 1 of the first 3 subjects in a dose group developed DLT during the DLT observation period after the first combination administration, an additional 3 subjects were added to the dose group.If none of the additional 3 subjects developed DLT, the next incremental dose group was entered.If DLT appears in 1 or more of the additional 3 subjects, the investigator shall decide whether to adjust the regimen, or increase the regimen, or terminate the climb.If DLT appears in 2 or more subjects in the initial 3 subjects of a dose group during the observation period of the first combined DLT, the investigator shall decide whether to adjust the dosing regimen, or increase the dosing regimen, or terminate the climbing. 2. In phase 2, 24 patients will be further included under the initially determined dose level and the appropriate administration regimen. Disease control rate (DCR) will be calculated according to the data obtained in phase 1, and the group with the highest DCR dose will be selected for the expansion study.