Safety Assessments
DLT was defined as any treatment-related AE (TRAE) grade 3 or higher that occurred during the 21-day DLT assessment window. Any dose-escalation patient who did not complete the DLT period for any reason other than a DLT was replaced by an additional patient at that same dose level. DLT-evaluable patients were required to have received the planned cycle 2 dose of pembrolizumab within 7 days of the planned administration date and to have taken 75% or more of the planned doses of cabozantinib in cycle 1. The MTD was defined as the highest dose level with no more than 1 DLT reported in 6 DLT-evaluable subjects. The RP2D of cabozantinib was selected on the basis of the clinical data, not exceeding the MTD. If <2/6 subjects experience a DLT at 60 mg daily during dose escalation, then 60 mg daily would be considered the RP2D.AEs were recorded throughout the study and during the follow-up period and graded according to NCI CTCAE Version 4.0 (