Immunotherapy in Gastric Cancer: A Review

Globally, gastric cancer (GC) ranks fourth in terms of cancer-related mortality. Patients diagnosed with advanced gastric cancer (AGC) frequently have a median survival around 12-15 months, depending to the therapy. Immunotherapy is becoming an essential therapeutic strategy in medical oncology, and it is projected to make major advances to the way gastric cancer cure. The phase III ATTRACTION-2 showed that nivolumab, a monoclonal antibody targeting programmed cell death 1 (PD-1), substantially increased overall survival (OS) in patients with advanced gastric cancer (AGC) when given as a third- or later-line treatment, as compared to a placebo. Furthermore, nivolumab in combination with 5-fluorouracil and platinum as a first-line treatment increased OS in patients with human epidermal growth factor receptor-2 (HER2)-negative AGC in the international phase III CheckMate-649 investigation. Pembrolizumab, an additional anti PD-1 antibody, when used with trastuzumab and cytotoxic chemotherapy as first line treatment, demonstrated a substantial enhancement in the overall response rate among patients diagnosed with HER2-positive AGC. Hence, immune checkpoint inhibitors (ICIs) are crucial in the present management of GC. Current research is actively investigating alternative treatment following ICI combination therapy, including ICI rechallenge or combination therapy with drugs that have distinct mechanisms of action. Several clinical trials are presently being done to employ immunotherapy as a treatment option in the perioperative and postoperative settings for patients with early gastric cancer, based on the success of immunotherapy in treating advanced gastric cancer (AGC). This article gives an overview of the recent breakthroughs in immunotherapy.