Efficacy of immune checkpoint inhibitor therapy in patients with RET fusion-positive non-small-cell lung cancer

Aim: To describe outcomes of patients with RET fusion-positive non-small-cell lung cancer (NSCLC) who received immune checkpoint inhibitor (ICI)-based treatments in the US. Patients & methods: Using de-identified Flatiron Health-Foundation Medicine NSCLC Clinico-Genomic and Guardant Health databases, treatment patterns and outcomes of 69 patients with advanced/metastatic RET fusion-positive NSCLC who received ICI-based treatment were described. Results: Median real-world progression-free survival and overall survival months were 4.2 (95% CI: 1.4-8.4) and 19.1 (6.9-not reached), respectively, among patients in Clinico-Genomic database (n = 17) receiving first-line ICI-based therapy. In the Guardant Health database, progression-free survival was unavailable, and the median overall survival was not reached (n = 29). Conclusion: Outcomes associated with ICI-based treatments in the first-line setting among patients with RET fusion-positive NSCLC are consistent with unselected populations reported in literature. Lay abstract Treatment options are rapidly expanding for patients who are diagnosed with advanced/metastatic non-small-cell lung cancer. The current standard of care for patients who do not have an actionable genomic alteration includes immune checkpoint inhibitor (ICI)-based therapy. However, the role of ICI-based therapy is not well understood in patients with REarranged during Transfection (RET) fusions. In this study, the survival outcomes observed in patients with RET fusion-positive non-small-cell lung cancer who received first-line ICI-based therapy were comparable with published data from patients without genomic alterations. This study is limited due to the small sample size. Tweetable abstract Observed patient characteristics are largely consistent with current knowledge in RET fusion-positive NSCLC. Observed outcomes in the first-line setting are consistent with unselected populations.