EGFR-TKIs plus stereotactic body radiation therapy (SBRT) for stage IV Non-small cell lung cancer (NSCLC): A prospective, multicenter, randomized, controlled phase II study.

ABSTRACT

BACKGROUND: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have a significant therapeutic effect in the treatment of advanced non-small-cell lung cancer (NSCLC) with EGFR mutations. However, the acquired resistance greatly limits the survival benefit of EGFR-TKIs for EGFR-mutant NSCLC patients. We aimed to assess the efficacy and safety of stereotactic body radiotherapy (SBRT) plus EGFR-TKIs in these patients. METHODS: In this prospective, randomized, controlled, phase 2 study, participants were recruited from 4 different hospitals in Wuhan, China. Eligible patients were histologically confirmed to have NSCLC with an EGFR-sensitive mutation (19DEL or 21L858R) and diagnosed at stage IV. Patients who had received first-line EGFR-TKIs treatment including gefitinib, erlotinib, and icotinib and achieved stable disease or partial response were enrolled after three months. Eligible participants were randomly assigned (11) to receive SBRT plus EGFR-TKIs or EGFR-TKIs treatment alone. In the combination-group, different tumor sites were irradiated at doses ranging from 30-50 Gy in five fractions. Considering the short duration of SBRT, the TKIs were continued during the radiotherapy. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS) and safety. This study was registered at ClinicalTrials.gov, with the registration number of NCT03595644. RESULTS: Between May 4, 2018 and Dec 20, 2019, 74 patients were screened, of whom 62 patients were enrolled and randomized. The study was closed early with 62/72 patients due to slow accrual. The enrolled patients were randomly assigned to receive SBRT plus EGFR-TKI(n = 31) or EGFR-TKI alone (n = 31). One patient who was randomized to the SBRT plus EGFR-TKI group refused to receive SBRT during the treatment, and, 61 patients were included the modified intention-to-treat (mITT) analysis, with 30 in the SBRT plus EGFR-TKI and 31 in the EGFR-TKI group. As of the clinical cutoff date (Feb 14, 2022), the median follow-up was 29.4 months (IQR 6.9-38.9). The median PFS of the EGFR-TKI group and SBRT combination group was 9.0 vs 17.6 months (hazard ratio [HR] = 0.52, 95% confidence interval [95%CI], 0.31-0.89, P = 0.016). Meanwhile, the median OS was 23.2 vs 33.6 months (HR [95%CI], 0.53(0.30-0.95); P = 0.026). There was no grade 3 or greater toxicity observed in either group, the grade 2 adverse events were 50% in the EGFR-TKIs + SBRT group while the percentage was 45.2% in the EGFR-TKIs group. CONCLUSIONS: The addition of SBRT significantly delayed the onset of acquired resistance to EGFR-TKIs and prolonged the PFS and OS of patients. Radiotherapy of the primary lesion alone might be superior to metastatic sites. Further confirmatory studies are needed to confirm our findings.