Kohie Shitara, MD, spoke about the use of immunotherapy in the first-line setting for metastatic gastric cancer.
At the 2022 International Gastric Cancer Conference, Kohei Shitara, MD, chief in the Department of Gastrointestinal Oncology at the National Cancer Center Hospital East in Kahiwa, Japan, sat down with CancerNetwork® and discussed using checkpoint inhibitors in front-line gastric cancer. He also spoke about the CheckMate649 study (NCT02872116) and the survival benefit seen in patients with advanced gastric, gastroesophageal junction, and esophageal adenocarcinoma who were treated with nivolumab (Opdivo) plus chemotherapy vs chemotherapy alone.1
We have an immune checkpoint inhibitor anti–PD-1 therapy nivolumab plus chemotherapy in front-line for gastric cancer. This is especially recommended for patients with PD-L1, or CPS [combined positive score] of 5 or higher globally based on CheckMate649 and its subgroup analysis. Meanwhile, there is controversy with its use for PD-L1 CPS of less than 5, according to the subgroup; there was a lesser [survival] benefit in this population.
Importantly MSI [microsatellite instability]–high patients achieved remarkable survival benefit with the checkpoint inhibitor in the CheckMate649 study and other previous studies of checkpoint inhibitors in gastric cancer. This is a very important biomarker, so it’s better to test all patients for it in the front-line. About 20% to 30% of MSI-high patients showed PD-L1 with a CPS as low as 5, so a CPS test alone may miss MSI-high populations. Recently, in pembrolizumab [Keytruda] plus trastuzumab and chemotherapy was approved the United States for HER2-positive gastric cancer with accelerated approval from the FDA.2 Overall, MSI [status], PD-L1 CPS, and HER2 are always important [to determine] before we start immunotherapy.
1. Janjigian YY, Shitara K, Moehler M, et al. First-line nivolumab plus chemotherapy versus chemotherapy alone for advanced gastric, gastro-oesophageal junction, and oesophageal adenocarcinoma (CheckMate 649): a randomised, open-label, phase 3 trial. Lancet. 2021;398(10294):27-40. doi:10.1016/S0140-6736(21)00797-2
2. FDA grants accelerated approval to pembrolizumab for HER2-positive gastric cancer. News Release. FDA. May 5, 2021. Accessed March 8, 2022. https://bit.ly/3pMQYcC