Introduction: Patients with EGFR-mutant lung cancer who have had disease progression on osimertinib commonly receive platinum doublet chemotherapy, but whether adding immunotherapy or bevacizumab provides additional benefit is unknown.
Materials and methods: This was a retrospective analysis at 2 university-affiliated institutions. Patients with EGFR-mutant lung cancer who had progression on osimertinib and received next-line therapy with platinum doublet chemotherapy (chemo), platinum doublet chemotherapy plus immunotherapy (chemo-IO), or platinum doublet chemotherapy plus bevacizumab (chemo-bev), were identified; patients who continued osimertinib with these regimens were included. Efficacy outcomes including duration on treatment (DOT) and overall survival (OS) from the start of chemotherapy were assessed. Associations of treatment regimen with outcomes were evaluated using adjusted Cox regression models, using pairwise comparisons between groups.
Results: 104 patients were included: 57 received chemo, 12 received chemo-IO, and 35 received chemo-bev. In adjusted models, patients who received chemo-IO had worse OS than did those who received chemo (hazard ratio (HR) 2.66, 95% CI 1.25-5.65; P= .011) or those who received chemo-bev (HR 2.37, 95% CI 1.09-5.65; P= .030). A statistically significant difference in OS could not be detected in patients who received chemo-bev versus those who received chemo (HR 1.50, 95% CI 0.84-2.69; P= .17).
Conclusion: In this retrospective study, giving immunotherapy with platinum doublet chemotherapy after progression on osimertinib was associated with a worse OS compared with platinum doublet chemotherapy alone. Platinum doublet chemotherapy without immunotherapy (with consideration of continuation of osimertinib, in selected cases) is a reasonable choice in this setting, while we await results of clinical trials examining optimal next-line chemotherapy-based regimens in EGFR-mutant lung cancer.
Keywords: Atezolizumab; Chemo-immunotherapy; Driver mutations; Pembrolizumab; Targeted therapy.
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