It has been established that treatment with immune checkpoint inhibitors (ICIs) can improve survival rates in patients with non-small cell lung cancer (NSCLC). What remains less understood is the link between duration of immunotherapy and overall survival in advanced NSCLC. Some clinicians take a “more is better” approach, despite inherent disadvantages to indefinite-duration therapy, including medical (treatment-related adverse events) and financial toxic effects. Dr Lova Sun and colleagues conducted a retrospective, population-based cohort study of patients from a US oncology database to assess practice patterns and evaluate the impact of duration of therapy on overall survival in patients who received 2-year fixed-duration ICI therapy vs those receiving ICI treatment for an indefinite duration.
A total of 1,091 patients who were still on treatment after 2 years and met study criteria were included in the analysis. The researchers found there was no survival advantage with longer duration of ICI treatment. Two-year overall survival from 760 days was 79% in patients in the fixed-duration group and 81% in the indefinite-duration group. Approximately 1 in 5 patients discontinued treatment in the absence of disease progression or death, suggesting that the majority of patients received indefinite-duration ICI treatment. The study also demonstrated that patients treated with fixed-duration therapy may benefit from rechallenge with ICI. Consistent with results from previous research, patients who underwent ICI rechallenge had a median progression-free survival of 8.1 months, with more than one-third of patients still on treatment at the data cutoff point.
This study provides reassurance to patients and clinicians who wish to discontinue immunotherapy at 2 years. In an Editor’s Note, Dr Howard (Jack) West stated that “the perfect should not be the enemy of the good.” He noted that while prospective randomized clinical trial data are needed, such a study will be difficult to complete, and results will take many years. Until further data are available, the current study by Sun and colleagues demonstrates that the discontinuation of ICI treatment at 2 years confers nearly identical survival results with a lower risk of toxic effects, less time in treatment for patients, and considerably lower costs for the healthcare system overall.
The results of this study support the use of fixed-duration ICI therapy in patients who receive and continue to experience clinical benefit, without compromising long-term survival. Further research is needed to expand on these results and confirm the optimal duration of immunotherapy and overall survival in advanced NSCLC. Studies evaluating other time points of treatment cessation may provide additional insights and support clinical guidance to inform treatment decisions.
This study provides valuable insight into the optimal duration of immunotherapy and overall survival in advanced NSCLC. In line with previous research, it supports that for patients with advanced NSCLC whose disease is still responding to ICI therapy, stopping ICI treatment at 2 years and monitoring rather than continuing immunotherapy indefinitely is a valid approach that does not appear to compromise survival outcomes.