Overall survival (OS) from random assignment in (A) the intent-to-treat (ITT) population, (B) the progression-free survival (PFS) population, (C) patients with complete response/partial response (CR/PR; PFS population), (D) patients with stable disease (SD) at random assignment (PFS population), and (E) patients with progressive disease (PD) before random assignment (ITT population). Random assignment took place after 1 year (y) of treatment with nivolumab. The ITT population comprised all patients who continued to receive treatment at 1 year and were randomly assigned, regardless of response status. The post–random assignment PFS population comprised patients who did not have PD and had not initiated other systemic anticancer therapy before random assignment. Minimum follow-up after random assignment in the ITT population was 13.5 months overall; median follow-up times after random assignment in the ITT population were 39.8 months and 34.4 months for the continuous and 1-year fixed-duration treatment arms, respectively; median follow-up times after random assignment in the PFS population were 40.5 months and 35.2 months for the continuous and 1-year fixed-duration treatment arms, respectively. HR, hazard ratio; NR, not reached. (*) Optional retreatment allowed at PD.