Dr. Vijayvergia on the Efficacy of Pembrolizumab in MSI-H Advanced Gastric Cancer

Namrata (Neena) Vijayvergia, MD, assistant chief of Gastrointestinal Medical Oncology, an assistant professor in Department of Hematology/Oncology, and medical director of Medical Oncology at the Fox Chase Cancer Center, discusses the efficacy of pembrolizumab (Keytruda) with or without chemotherapy in patients with microsatellite instability–high (MSI-H) advanced gastric cancer.

In the phase 3 KEYNOTE-062 study (NCT02494583), approximately 5% of the patients in the pembrolizumab monotherapy arm were MSI-H, as well as 7% of patients in the chemotherapy-alone arm and 8% of those in the pembrolizumab plus chemotherapy arm, according to Vijayvergia. Results demonstrated that a number of MSI-H tumors were enriched in patients who were PD-L1 positive, Vijayvergia adds.

Moreover, a clear benefit with pembrolizumab plus chemotherapy was reported in this patient population over chemotherapy alone, Vijayvergia says. Data in early-stage disease also indicate that patients with MSI-H disease may not respond well to chemotherapy alone; this could also apply to the metastatic setting, Vijayvergia notes. Currently, pembrolizumab, with or without chemotherapy, appears to be an effective option for patients with MSI-H disease, Vijayvergia concludes.