Long-term outcomes in patients with advanced and/or metastatic non-small cell lung cancer who completed 2 years of immune checkpoint inhibitors or achieved a durable response after discontinuation without disease progression: Multicenter, real-world data (KCSG LU20-11)

Background Immune checkpoint inhibitors (ICIs) have shown significant improvements in patients with advanced non-small cell lung cancer (NSCLC). One of the major issues with ICIs is determining the optimal treatment duration. Methods This multicenter, retrospective study analyzed clinical outcomes in patients with NSCLC who completed 2 years of ICI therapy or were treated for more than 6 months and then discontinued ICIs without disease progression at 11 medical centers in Korea between August 2017 and December 2020. Results Ninety-six patients who completed 2 years of ICIs were reviewed. The median durations of treatment and follow-up were 24.0 and 33.9 months, respectively. The objective response rate (ORR) was 85.4%. The median progression-free survival (PFS) and overall survival (OS) periods were not reached. After completion, the PFS and OS rates were 81.1% and 96.4%, respectively, at 12 months. Forty-three patients were identified who discontinued ICIs without disease progression: 26 (60.5%) for adverse events and 17 (39.5%) for other causes. The median durations of treatment and follow-up were 10.5 and 21.2 months, respectively. The ORR was 90.7%. The median PFS and OS periods were not reached. After discontinuation, the PFS and OS rates were 71.0% and 90.0%, respectively, at 12 months. Conclusions A significantly high proportion of patients who completed 2 years of ICI therapy continued to experience long-term PFS. Even if ICIs are discontinued after 6 months in patients without disease progression, they may achieve a durable response and facilitate long-term survival. Lay Summary The optimal treatment duration for immune checkpoint inhibitors (ICIs) remains to be determined. This study reports the long-term outcomes of patients with non-small cell lung cancer who completed 2 years of ICI therapy or achieved a durable response after the discontinuation of ICIs without disease progression in real-world practice. A significantly high proportion of patients who completed 2 years of ICIs continued to experience long-term progression-free survival. In addition, even if ICIs are discontinued after 6 months in patients without disease progression, they may achieve a durable response and facilitate long-term survival.