Abstract CT216: Anti-EGFR in combination with paclitaxel as second-line therapy for gastric cancer with EGFR overexpression

Abstract Background: We and other investigators reported that EGFR gene is amplified in 2-4% of gastric cancer with protein overexpression (Gastroenterology 2017 Aug;153 (2): 536-549; Cancer Cell 2019 Jan 14; 35: 1: 111: E10), but EGFR-targeted therapy has not entered into clinic. Patients and Methods: As a subprotocol of the investigator-initated of umbrella trial, patients with metastatic gastric cancer received weekly anti-EGFR monoclonal antibody (GC-1118 (GC Biopharma), 2. 5mg/kg) in combination with paclitaxel 80mg/m2 (D1, D8, D15) every 4 weeks as a second-line therapy, if the gastric cancer tissue sample revealed EGFR protein overexpression (NCT04077255). Projected accrual was 19 based on minimax two-stage design (P1=45%; P0=15%; alpha and beta errors, 0. 05 and 0. 1, respectively). Results: Among 19 evaluable patients, 6 patients had objective clinical response (RR, 31. 6%). Median progression-free survival was 4. 7 months (95% CI, 1. 8-5. 1). Median overall survival was 7. 6 months (95% CI, 4. 2-11. 1). Predictive biomarkers were explored by post hoc correlative analyses. Conclusion: EGFR inhibition, in combination with paclitaxel, demonstrated modest activity for gastric cancer refractory to first-line 5-FU/platinum-based chemotherapy. (This study was supported by a grant from the National R Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (7Suppl): Abstract nr CT216.