Dr. Ilson Discusses Challenges with Immunotherapy in Gastric Cancer

David H. Ilson, MD, PhD, medical oncologist, Memorial Sloan Kettering Cancer Center, discusses remaining challenges with immunotherapy in gastric cancer.

A key remaining challenge in gastric cancer is the need for more effective biomarkers to select which patients will benefit most from immunotherapy, says Ilson, as only a small subset of patients with the disease will benefit from this approach.

It is known that patients with microsatellite instablity—high (MSI-H) tumors will typically experience a high degree of benefit from checkpoint inhibitors, but that is not always the case, says Ilson. Some patients with MSI-H tumors will not respond to immunotherapy, and in some cases, a small percentage of patients will experience hyper-progression. When this happens, the patient's tumor will grow even more quickly once exposed to these agents, explains Ilson.

Currently, MSI and PD-L1 are the only 2 biomarkers that are available in the space, although CPS scores have also been looked at, says Ilson. For example, patients with CPS scores that are 10% or higher might achieve a greater benefit from immunotherapeutics than those whose scores are just 1%, says Ilson. The hunt for more effective biomarkers is not the only thing that will propel the field forward, he adds.

To do that, investigators must examine other avenues to overcome immune suppression. Other targets and newer drugs are also needed, concludes Ilson.