2.3. Outcomes

The primary endpoint was the intracranial and extracranial overall response rate (ORR), which was defined as the percentage of patients who achieved intracranial and extracranial partial (PR) or complete (CR) response according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The intracranial ORR was also assessed according to the RANO-BM criteria. As secondary endpoints, we assessed the following: centrally reviewed intracranial progression-free survival (cPFS), defined as the time from the start of pembrolizumab treatment to disease intracranial progression according to the Response Evaluation Board (RECIST) 1.1 or death from any cause; PFS, defined as the time from the date of pembrolizumab start to the date of first disease progression or any-cause death; OS, defined as the time from the start of follow-up to the date of death from any cause and determined at the date of last contact or cutoff date (18 January 2021); and the safety and toxicity of pembrolizumab according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0.