The optimal duration of immune checkpoint inhibitor therapy in advanced non-small cell lung cancer: a systematic review of clinical trials

Immune checkpoint inhibitor (ICI) offer hope for patients with advanced non-small cell lung cancer; however, there is no consensus on the optimal course of treatment. This study aims to evaluate the optimal duration of immune checkpoint inhibitors in patients with advanced non-small cell lung cancer. A systematic search of published studies was conducted in PubMed, Cochrane, Embase, CNKI, Wanfang, and VIP databases until January 2026. Retrieved articles were screened for final inclusion and relevant data were extracted, including median progression-free survival (mPFS), median overall survival (mOS), 1-year overall survival rate (%), 2-year overall survival rate (OS) (%), 1-year progression-free survival (%), 2-year progression-free survival (PFS) (%). Six studies were included: four cohort studies, one RCT, and one single-arm study. One cohort study showed no significant difference in OS between the two-year and greater-than-two-year groups. Another cohort study showed superior 1-year OS and PFS rates in the two-year ICI group compared to the less than two-year group. A third cohort study found that ICI use for greater than or equal to one year was superior to less than one year in terms of mPFS and mOS. In the fourth cohort study, compared to the 6–18 month group, the ≥ 18 month group demonstrated no significant difference in mPFS, but mOS was better.The RCT indicated that continuous ICI treatment was better than a 1-year fixed regimen in mPFS, mOS, 1-year and 2-year OS rates (%), and 1-year and 2-years PFS rates (%). The single-arm study reported 1-year and 2-year OS and PFS rates for patients treated with ICIs for more than 18 months. Only one study evaluated safety. The RCT reported a higher risk of treatment-related adverse events (TRAEs), including grade 3 or higher TRAEs and TRAEs leading to treatment discontinuation, in the continuous treatment group compared to the 1-year fixed treatment group. In patients who respond to ICI and have received treatment for more than a year, good antitumor efficacy and safety were demonstrated.However, for patients who have been continuously receiving ICI treatment for more than two years, no significant difference in OS benefit seems to be observed.