First-Line Apatinib Combined with Tislelizumab and Chemotherapy for Patients with Advanced Gastric and Gastroesophageal Junction Adenocarcinoma with Poor Prognosis.

In this prospective, open-label, exploratory study (RENMIN-213), patients with previously untreated, HER2-negative, advanced G/GEJ adenocarcinoma with signet ring cell carcinoma or peritoneal metastasis were enrolled to receive eight cycles of apatinib, tislelizumab, and chemotherapy every 3 weeks, with a maintenance therapy with apatinib plus tislelizumab for a maximum of 1 year. Homogeneous patients receiving immune checkpoint inhibitors combined with chemotherapy at the same time were deemed as the control group for efficacy. The primary endpoint was progression-free survival. Secondary endpoints were objective response rate, disease control rate, duration of response, overall survival, biomarkers, health-related quality of life, and safety. A total of 33 patients [median (range) age, 60 (32-72) years; 21 (63.6%) male; 11 (33.3%) signet ring cell carcinoma; 30 (90.9%) peritoneal metastasis] were enrolled and deemed evaluable for efficacy analysis. Of these patients, 32 (97%) were without disease progression, of whom 1 (3.0%) patient had complete response and 18 (54.6%) had partial response. Six patients (18.2%) were able to undergo surgery after treatment. After propensity score matching, the median progression-free survival was 10.17 months (95% confidence interval, 7.13-13.21) in the apatinib combined with tislelizumab and chemotherapy group, as compared with 6.0 months in the immune checkpoint inhibitor combined with chemotherapy group. The median duration of response increased from 4.5 to 8.7 months. The objective response rate increased from 33.3% to 54.6%, and the disease control rate increased from 87.9% to 97.0%. Treatment-related grade 3 or higher adverse events for evaluable patients occurred in 11 patients (33.3%), and patients' health-related quality of life improved after treatment.