Phase 2 trial of consolidative stereotactic radiotherapy for oligo-residual EGFR-mutant NSCLC after first-line third-generation EGFR-TKI

A phase 2 study at two centers in China evaluated addition of consolidative stereotactic radiotherapy (SRT) in patients harboring oligo-residual disease (ORD) after first-line third-generation EGFR-TKI for EGFR-mutant metastatic non-small cell lung cancer (mNSCLC). The median progression-free survival was 29.9 months (80% CI 22.4-32.4) among all patients (a) and 16.9 months (16.3-NA) among patients receiving SRT for brain metastases (b). The median overall survival was not reached with a median follow-up of 21.1 months; two-year OS rate was 86.4%. Treatment-related adverse events occurred in 70% of patients; grade ≥ 3 TRAEs occurred in 6.6%. Propensity score matched comparison with a contemporary cohort of patients who developed ORD but did not receive SRT found that SRT was associated with significantly prolonged PFS (HR 0.46; p=0.002). The authors conclude that consolidative SRT was associated with encouraging PFS in first-line third-generation EGFR-TKI-treated mNSCLC patients harboring ORD, with generally acceptable toxicities.