Randomized Trial of First-Line Tyrosine Kinase Inhibitor With or Without Radiotherapy for Synchronous Oligometastatic EGFR-Mutated NSCLC

Adding radiotherapy (RT) to systemic therapy improves progression-free survival (PFS) and overall survival (OS) in oligometastatic non-small cell lung cancer (NSCLC). Whether these findings translate to EGFR-mutated NSCLC remains unknown. The SINDAS trial (NCT02893332) evaluated first-line tyrosine kinase inhibitor (TKI) therapy for EGFR-mutated synchronous oligometastatic NSCLC, and randomized to up-front RT vs. no RT; we now report the pre-specified interim analysis at 68% accrual.Inclusion criteria were biopsy-proven EGFR-mutated adenocarcinoma (per amplification refractory mutation system or next generation sequencing), with synchronous (newly-diagnosed, treatment-naïve) oligometastatic (≤5 metastases; ≤2 lesions in any one organ) NSCLC without brain metastases. All patients received a first-generation TKI (gefitinib, erlotinib, or icotinib), and randomization was between no RT vs. RT (25-40 Gy in 5 fractions depending on tumor size/location) to all metastases and the primary tumor/involved regional lymphatics. The primary endpoint (intention-to-treat) was PFS. Secondary endpoints included OS and toxicities. All statistical tests were 2-sided.A total of 133 patients (n = 65 TKI only, n = 68 TKI+RT) were enrolled (2016-2019). The median follow-up was 23.6 months. The respective median PFS was 12.5 months vs. 20.2 months (p .001), and the median OS was 17.4 months vs. 25.5 months (p .001) for TKI only vs TKI+RT. Treatment yielded no grade 5 events and a 6% rate of symptomatic grade 3-4 pneumonitis in the TKI+RT arm. Based on the efficacy results of this pre-specified interim analysis, the ethics committee recommended premature cessation of this trial.As compared to a first-line TKI alone, addition of up-front local therapy using RT statistically significantly improved PFS and OS for EGFR-mutated NSCLC.