Abstract CT152: A multicenter Phase II study of savolitinib in patients with MET-amplified gastroesophogeal junction adenocarcinomas or gastric cancer

Abstract Background: MET gene amplification is associated with poor prognosis in gastric cancer (GC) and gastroesophageal junction adenocarcinomas (GEJ). Savolitinib is a potent and highly selective oral MET tyrosine-kinase inhibitor. Here we reported the preliminary efficacy and safety from a phase 2 trial of savolitinib monotherapy in patients (pts) with MET-amplified advanced or metastatic GC/GEJ. (NCT04923932). Methods: Eligible pts had 2L+ GEJ or GC, with MET amplification and measurable lesions. Pts received savolitinib at 600 mg QD for body weight (BW) ≥50 kg, while 400 mg QD for BW <50 kg in 21-day cycles until disease progression or meeting other criteria for end of treatment. Savolitinib BID regimen has also been additionally explored. The primary endpoint was objective overall response rate (ORR) evaluated by Independent Review Committee (IRC). One interim analysis (IA) was pre-defined at the first 20 QD pts who had at least 2 tumor assessments. Results: As of IA, 20 pts were enrolled for QD regimen. Demographics and clinical outcomes are shown in table 1. The mean relative dose intensity of 93.07%. Median duration of exposure was 2.09 months. Confirmed ORR by IRC was 45%, and reached 50% in 16 patients with MET GCN (high) while only 1 PR was observed in 4 patients with MET GCN (low). Duration of response rate at 4-month was 85.7% with median follow up time of 5.5 months. The most common Gr≥3 TRAE (≥5%) were platelet count decreased, hypersensitivity, anemia, neutropenia and hepatic function abnormal. In all pts, only 1 patient discontinued treatment due to grade 4 liver function abnormal (TRAE) and no patient died due to TRAE. Conclusion: Savolitinib monotherapy had manageable safety and showed promising efficacy in pts with MET-amplified GEJ or GC, particularly in pts with MET high GCN. BID regimen is being investigated to further evaluate the efficacy and safety of savolitinib in pts with MET high GCN. Table 1. Pts baseline characteristics and clinical efficacy Baseline Characteristics ITT in IA (n=20) Median age (min, max), yearsSex (male/female), nECOG (0/1/2)Median BMI (min, max), (kg/m2)Primary location of tumor (GC/GEJ)Tumor stage (IV)Prior line of therapy (1/2/≥3)MET GCN (high/low) 57.00 (39.5, 76.8)17/33/15/220.8 (14.9, 25.8)16/4205/10/516/4 Clinical Efficacy By IRC By Investigator Confirmed objective response rateDisease control rate4m-DoR rate,% (95% CI) 45%65%85.7 (33.4, 97.9) 40%55%71.4 (25.8, 92.0) Citation Format: Zhi Peng, Hua Wang, Baorui Liu, Huiting Xu, Zhenyang Liu, Tianshu Liu, Jun Zhang, Yuxian Bai, Ying Yuan, Tao Wu, Feng Ye, Qinghua Pan, Jufeng Wang, Enxiao Li, Diansheng Zhong, Yueyin Pan, Yanru Qin, Yan Yang, Yusheng Wang, Aiping Zhou, Yongshun Chen, Dianbao Zhang, Hongli Liu, Xiujuan Qu, Shubin Wang, Ning Liu, Jinsheng Wu, Wei Li, Kejun Nan, Hongming Pan, Jianming Xu, Chunmei Bai, Heling Liu, Jia Wei, Runzhi Chen, Rongrong Li, Wei Li, Jinghong Zhou, Hongyan Yin, Qian Xu, Songhua Fan, Yongxin Ren, Weiguo Su, Lin Shen. A multicenter Phase II study of savolitinib in patients with MET-amplified gastroesophogeal junction adenocarcinomas or gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT152.