Study: NCT04183088

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Tislelizumab+regorafenib for part 1;Tislelizumab+regorafenib for group 1 of part 2; Regorafenib for group 2 of part 2.
Description: There will be no dose reduction for tislelizumab in this study. In the part 1(safety cohort), if the subjects do not experience grade 2 or greater regorafenib-related adverse events after 2 cycles (6 weeks) of treatment, the dosage of regorafenib may be escalated. For subjects who escalate the regorafenib dosage to Level 2, if the subjects do not experience grade 2 or greater regorafenib-related adverse events after 2 cycles of study drug treatment, the dosage of regorafenib may be further escalated to Level 3.~During study drug treatment, dose delay/ interruption of regorafenib will be done depending on the occurrence and severity of regorafenib-related adverse events. After dose reduction of regorafenib, if the subjects tolerate the reduced dose of regorafenib well, the investigators may consider re-escalation of regorafenib to the previous dose level, depending on the types and severity of adverse events that led to dose reduction.

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Tislelizumab+regorafenib for part 1;Tislelizumab+regorafenib for group 1 of part 2; Regorafenib for group 2 of part 2.
Description: There will be no dose reduction for tislelizumab in this study. In the part 1(safety cohort), if the subjects do not experience grade 2 or greater regorafenib-related adverse events after 2 cycles (6 weeks) of treatment, the dosage of regorafenib may be escalated. For subjects who escalate the regorafenib dosage to Level 2, if the subjects do not experience grade 2 or greater regorafenib-related adverse events after 2 cycles of study drug treatment, the dosage of regorafenib may be further escalated to Level 3.~During study drug treatment, dose delay/ interruption of regorafenib will be done depending on the occurrence and severity of regorafenib-related adverse events. After dose reduction of regorafenib, if the subjects tolerate the reduced dose of regorafenib well, the investigators may consider re-escalation of regorafenib to the previous dose level, depending on the types and severity of adverse events that led to dose reduction.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Tislelizumab+regorafenib for part 1;Tislelizumab+regorafenib for group 1 of part 2; Regorafenib for group 2 of part 2.
Description: There will be no dose reduction for tislelizumab in this study. In the part 1(safety cohort), if the subjects do not experience grade 2 or greater regorafenib-related adverse events after 2 cycles (6 weeks) of treatment, the dosage of regorafenib may be escalated. For subjects who escalate the regorafenib dosage to Level 2, if the subjects do not experience grade 2 or greater regorafenib-related adverse events after 2 cycles of study drug treatment, the dosage of regorafenib may be further escalated to Level 3.~During study drug treatment, dose delay/ interruption of regorafenib will be done depending on the occurrence and severity of regorafenib-related adverse events. After dose reduction of regorafenib, if the subjects tolerate the reduced dose of regorafenib well, the investigators may consider re-escalation of regorafenib to the previous dose level, depending on the types and severity of adverse events that led to dose reduction.