Chemotherapy for patients with EGFR-mutated NSCLC after progression on EGFR-TKI's: Exploration of efficacy of unselected treatment in a multicenter cohort study

Objectives: In patients with Epidermal Growth Factor Receptor (EGFR)-mutated non-small cell lung (NSCLC) chemotherapy remains standard of care after progression on EGFR-tyrosine kinase inhibitors (TKIs). With the development of anti-angiogenic agents and immune checkpoint inhibitors the landscape of systemic regimens has changed significantly. This cohort study aims to evaluate the efficacy of chemotherapy regimens after progression on EGFR-TKI in a European population. Material and Methods: All consecutive patients treated with chemotherapy after progression on EGFR-TKI for EGFR-mutated NSCLC, were identified in two tertiary centers in the Netherlands. Data on best response, progression free survival (PFS) and overall survival (OS) were extracted from medical records. Results: In total, 171 lines of chemotherapy were identified: platinum/pemetrexed (PP, n = 95), carboplatin/paclitaxel/bevacizumab/atezolizumab (CPBA, n = 32), paclitaxel/bevacizumab (PB, n = 36) and carboplatin/paclitaxel/bevacizumab (CPB, n = 8). Of the 171 lines, 106 were given as first-line after EGFR-TKI. Median PFS did not differ significantly between the first-line regimens (p = 0.50), with the highest PFS in PP (5.2 months [95% CI 4.5–5.9]) and CPBA (5.9 months [95% CI 3.8–80]). The majority of the PB group (n = 32) received this regimen in a second- or later line with a median PFS of 4.9 months (95% CI 3.3–6.6). First-line regimens had a median OS of 15.3 months (95% CI 11.6–18.9) with no significant difference between regimens (p = 0.85). Conclusion: After progression on EGFR-TKI, patients with EGFR-mutated NSCLC show substantial benefit on different chemotherapy regimens. In particular, favorable outcomes were seen in patients treated with PP and CPBA as first-line chemotherapy, and PB in further lines of chemotherapy.