Efficacy of chemotherapy combined with immunotherapy in advanced lung adenocarcinoma harboring epidermal growth factor receptor exon 20 insertion () mutations: A retrospective comparative study.

[BACKGROUND] Although chemotherapy combined with immunotherapy is effective in advanced non-small cell lung cancer (NSCLC), its efficacy in patients with epidermal growth factor receptor exon 20 insertion mutations remains unclear.

[METHODS] This retrospective analysis included 66 patients: 28 received chemotherapy plus immunotherapy, and 38 received chemotherapy alone. The primary endpoint was progression-free survival (PFS), and the secondary endpoint was safety. In eligible patients with measurable disease, tumor response was assessed using the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. PFS was defined as the time from the first day of therapy to disease progression or death from any cause.

[RESULTS] The median progression-free survival (mPFS) was 10.5 months (95% confidence interval (CI): 7.03-16.63 months) in the chemotherapy plus immunotherapy group and 6.23 months (95% CI: 4.53-7.07 months) in the chemotherapy alone group. There was a significant difference in efficacy between the chemotherapy plus immunotherapy and chemotherapy-alone groups ( 0.001). Among the 25 patients evaluated for tumor response in the chemotherapy plus immunotherapy group, 11 (44%) achieved a partial response (PR), 8 (32%) had stable disease (SD), and 6 (24%) had progressive disease (PD). The objective response rate (ORR) was 44%. Adverse events (AEs) included gastrointestinal reactions and myelosuppression. There were no significant differences in terms of safety between the two treatment groups.

[CONCLUSIONS] First-line chemotherapy combined with immunotherapy was associated with significantly longer PFS than chemotherapy alone in patients with -mutant NSCLC, without increased toxicity.