Adjuvant icotinib versus observation in patients with completely resected EGFR-mutated stage IB NSCLC (GASTO1003, CORIN): a randomised, open-label, phase 2 trial

This phase 2 trial aimed to compare adjuvant icotinib with observation in patients with epidermal growth factor receptor (EGFR) mutation-positive resected stage IB non-small cell lung cancer (NSCLC).We performed a randomised, open-label, phase 2 trial from May 1, 2015 to December 29, 2020 at Sun Yat-sen University Cancer Center in China. Patients with completely resected, EGFR-mutant, stage IB (the 7th edition of TNM staging) NSCLC without adjuvant chemotherapy were randomised (1:1) to receive adjuvant therapy with icotinib (125 mg, three times daily) for 12 months or to undergo observation until disease progression or intolerable toxicity occurred. The primary endpoint was 3-year disease-free survival (DFS). CORIN (GASTO1003) was registered with Clinicaltrials.gov, with the number NCT02264210.A total of 128 patients were randomised, with 63 patients in the icotinib group and 65 patients in the observation group. The median duration of follow-up was 39.9 months. The three-year DFS was significantly higher in the icotinib group (96.1%, 95% confidence interval [CI], 91.3-99.9) than in the observation group (84.0%, 95% CI, 75.1-92.9; P = 0.041). The DFS was significantly longer in the icotinib group than in the observation group, with a hazard ratio (HR) of 0.23 (95% CI, 0.07-0.81; P = 0.013). The OS data were immature, with three deaths in the observation arm. In the icotinib group, adverse events (AEs) of any grade were reported in 49 patients (77.8%), and grade 3 or greater AEs occurred in four patients (6.3%). No treatment-related deaths occurred.Our findings suggested that adjuvant icotinib improved the 3-year DFS in patients with completely resected EGFR-mutated stage IB NSCLC with a manageable safety profile.This study was sponsored by Betta Pharmaceutical Co., Ltd.