Matched therapies for advanced gastric cancer based on genotype: A real-world study in China.

Abstract

e16098 Background: Systemic therapy options for patients with advanced gastric cancer (GC) are limited. We here presented the efficacy results for advanced GC patients matched to targeted therapies or immunotherapies based on the identification of tumor tissue genotypes. Methods: We selected 30 patients diagnosed between 2014 and 2020 with advanced GC at Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School identified with actionable alterations and received ≥1 matched therapies. Tumor biopsy specimens from the patients were analyzed using NGS and/or selected immunohistochemistry and fluorescence in situ hybridization. Results: In these 30 patients, median age at diagnosis was 63 years (range 28-83) and 6 (20%) were female. In total, 11 (37%) harbored c-MET amplification/overexpression (received savolitinib or crizotinib, cohort A), 9 (30%) harbored HER2 mutation/overexpression (received RC48-ADC or trastuzumab, cohort B), 6 (20%) dMMR/MSI-H/TMB-H (received sintilimab, pembrolizumab, tislelizumab or nivolumab, combined with antivascular or not, cohort C), 2 (7%) KIT mutation/amplification (received imatinib or anlotinib, cohort D), 1 (3%) BRAF V600E mutation (received vemurafenib, cohort E) and 1 (3%) EGFR mutation (received afatinib, cohort F). Except for three patients in cohort C, all patients received at least one previous line systemic therapy. In cohort A, three of 11 patients had an objective response (1 complete response and 2 partial responses, objective response rate (ORR) 27%), disease control rate (DCR) was 45%, median progression-free survival (mPFS) was 2.1 months, and median overall survival (mOS) was 3.7 months. In cohort B, ORR was 44% (4/9), DCR was 78% (7/9), mPFS and mOS was 3.1 months and 5.5 months, respectively. In cohort C, ORR was 17% (1/6), DCR was 67% (4/6), mPFS and mOS was 1.9 months and 6.8 months, respectively. In cohort D, no patient had objective response or disease control. In cohort E, the one patient had PR. Stable disease was observed in the patient in cohort F. In all cohorts, ORR was 30% (9/30), DCR was 60% (18/30), mPFS and mOS was 2.7 months and 5.8 months, respectively. Conclusions: Overall, 30 patients with advanced GC were treated with matched therapies according to specific genotype. These real-world outcomes suggested that matched therapies for advanced GC has promising efficacy, supporting the adoption of genotyping in treatment determination.