Adjuvant icotinib of 12 months versus observation as adjuvant therapy for completely resected EGFR-mutated stage IB non-small-cell lung cancer: 5-year update from CORIN (GASTO1003).

8021 Background: In the phase II CORIN trial,adjuvant therapy of icotinib for 1-year shows prolonged disease-free survival (DFS) and acceptable toxicity in patients with completely resected epidermal growth factor receptor (EGFR)-mutated stage IB non-small-cell lung cancer (NSCLC). Here, we report the 5-year survival update from this study. Methods: In the phase II, open-label, randomized CORIN trial, patients with completely resected, EGFR-mutated, stage IB (7th TNM staging) NSCLC without adjuvant chemotherapy according to physician and patient choice were randomly assigned in a 1:1 ratio to receive icotinib (125mg, three times daily, 12 months) or undergo observation. Therapy continued until disease recurrence or intolerable toxicity. The primary endpoint was DFS. Secondary endpoints included overall survival (OS) and toxicity. Results: Of 128 enrolled patients, 63 received icotinib and 65 underwent observation. At the December 20 2024 database lock, the median follow-up was 65.0 (95% confidence interval [CI], 58.4-71.5) months. A total of 30 recurrence events had occurred, including 9 in the icotinib arm and 21 in the observation arm. Icotinib for 1 year continued to improve DFS versus observation, with the 5-year DFS of 88.5% and 67.7%, respectively (log-rank P=0.012, hazard ratio [HR], 0.38; 95%CI: 0.18-0.83). Icotinib showed a marginal OS improvement versus observation (log-rank P=0.045, HR, 0.15; 95%CI: 0.02-1.27). The 5-year OS was 98.3% in the icotinib group and 90.5% in the observation group. No new safety signals were observed at this update. Additional efficacy outcomes will be presented. Conclusions: In this 5-year update analysis from CORIN, adjuvant icotinib continues to demonstrate durable DFS benefit versus observation in resected EGFR-mutated stage IB NSCLC, with a manageable safety profile. Icotinib sustained OS separation versus observation over time and demonstrated a marginal OS benefit, which is limited by the small sample size and wide CIs. Adjuvant icotinib for 1 year provides a treatment option for these patients. Clinical trial information: NCT02264210 .