Immune checkpoint inhibition in gastric cancer: A systematic review

Objectives

Checkpoint inhibitor therapy is revolutionizing the management of the oncological disease. Despite the fact that gastric cancer is a common malignancy with a relatively poor prognosis, checkpoint inhibitor therapy has attracted relatively little attention for the treatment of this disease. We decided to perform a systematic review focusing on the potential usefulness of checkpoint inhibitors in patients with gastric cancer by reviewing all clinical trials involving checkpoint inhibitors in gastric cancer up to the 9th of September 2017.

Methods

We systematically review all randomized controlled trials on the 9th September 2017. We searched the embase.com, Medline Ovid, Cochrane CENTRAL, Web of Science, Google Scholar, and databases of current ongoing randomized trials. A description assessment of randomized clinical trials (RCTs) was performed on Immune checkpoint inhibitors for PD1, CTLA4 and PD-L1 (Atezolizumab, Avelumab, Durvalumab, Ipilimumab, Nivolumab, Pembrolizumab, and Tremelimumab) in gastric cancer patients.

Results

The current body of biomedical literature describes 3621 gastric cancer patients being treated with checkpoint inhibitors and compared to patients receiving chemotherapy. PD-1 inhibitors pembrolizumab and nivolumab in combination appear to substantially outperform conventional chemotherapy, with more extended overall survival median (OS; 10.0 vs. 6.0 mo), a more significant objective response rate (36% versus 13%, p = 0.10), with a reduced adverse event rate (33% vs. 22%), although other checkpoint inhibitors appear somewhat less effective.

Translational Impact

It seems that checkpoint inhibitor therapy in general, and PD-1-directed therapy, in particular, constitutes a rational therapeutic avenue for advanced gastric cancer.