Immunotherapy plus chemotherapy showed superior clinical benefit to chemotherapy alone in advanced NSCLC patients after progression on osimertinib

Background Osimertinib is the standard first-line treatment for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation. Resistance to osimertinib remains a clinical challenge. However, the optimal therapy for these patients is still controversial. In this study, we aimed to assess the efficacy and safety of immunotherapy plus chemotherapy (IO+C) compared with chemotherapy (C) in NSCLC patients after progression on osimertinib. Methods Advanced NSCLC patients after progression on osimertinib were retrospectively reviewed. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety were evaluated between the patients treated with IO+C and C. Results A total of 40 patients were included in the study. There were 20 patients each in the IO+C group or C group. The ORR was significantly higher in patients in the IO+C group (45% vs. 25%, p < 0.01). The median PFS was 6.4 months for patients in the IO+C group compared to 2.8 months for patients in C group (HR: 0.41, 95% confidence interval [CI]: 0.20-0.82, p < 0.01). The median OS was significantly longer in the IO+C group than the C group (OS: 12.8 vs. 10.5 months, HR: 0.39, 95% CI: 0.19-0.80, p < 0.01). In subgroup analysis, patients of both sexes, age <= 65, bone or adrenal metastasis, exon19 del mutation, and third-line treatment obtained more OS benefits from immunotherapy. The safety profile of both groups was comparable. Conclusions Our study provides the clinical evidence of favoring immunotherapy plus chemotherapy in NSCLC patients after progression on osimertinib.