ABSTRACT
BACKGROUND: Mesenchymal epithelial transition factor (MET) is a rare oncologic driver gene, and information on immunotherapy for non-small cell lung cancer (NSCLC) patients with this driver gene is limited. Here we evaluate the efficacy and safety of immune checkpoint inhibitors (ICI) under different therapeutic regimen for NSCLC patients with MET alterations. METHODS: From June 2019 to December 2023, we assessed the efficacy and toxicity of ICIs in 42 NSCLC patients with MET alterations. Survival curves were plotted using the Kaplan-Meier method and the Cox proportional hazards model applied for univariate and multivariate analyses. We assessed the size of target lesion according to RECIST v1.1, and objective response rate (ORR) was defined as the sum of complete response (CR) and partial response (PR), disease control rate (DCR) as the sum of CR, PR, and disease stable. RESULTS: A total of 42 NSCLC patients with MET alterations were included in this retrospective study, 10 was MET 14 skipping mutation and 32 was MET amplification. The ORR for ICI treatment was 30.95% and the DCR was 71.43%. Median progression-free survival (mPFS) and median overall survival (OS) were 4.40 and 13.97 months, respectively. There exists statistical differences between the mPFS of ICI monotherapy and combine ICI therapy (2.8 vs 7.8 months, p = 0.022). The incidence of drug-related adverse reactions was 47.62%, mainly bone marrow suppression (14.28%), immune-related pneumonia (7.14%), and liver function impairment (7.14%), and six patients (14.28%) experiencing grade 3 or above adverse events. CONCLUSION: NSCLC patients with MET alterations can benefit from immunotherapy, especially the patients treated by combined ICI therapy. However, special attention should be paid to the occurrence of grade 3/4 adverse reactions while using the combined ICI therapy.