Phase 2 study of neoadjuvant durvalumab plus DOS chemotherapy followed by surgery and adjuvant durvalumab for locally advanced gastric cancer

A phase 2 study at Asan Medical Center (Seoul, South Korea) evaluated neoadjuvant durvalumab plus docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy followed by surgery and adjuvant durvalumab and S-1 among patients with pMMR locally advanced gastric cancer (LAGC). The pCR rate was 30.0% and unacceptable toxicities were observed in 10%, meeting both the efficacy and safety endpoints. With a median follow-up of 21.8 months, the 3-year progression-free and overall survival rates were 69.9% and 88.1%, respectively. In an exploratory arm of the study, patients with dMMR tumors received neoadjuvant durvalumab and tremelimumab. All of these patients underwent surgery, with a pCR rate of 22.2%. The authors conclude that among Asian patients with LAGC, the combination of neoadjuvant curvalumab and DOS, followed by surgery and adjuvant durvalumab plus S-1, warrant further investigation in a phase 3 trial.