Pembrolizumab in addition to trastuzumab and chemotherapy for HER2-positive advanced gastric or gastroesophageal junction adenocarcinoma – First-line

Pembrolizumab in addition to trastuzumab and chemotherapy is being developed for patients with HER2-positive advanced gastric or gastroesophageal junction adenocarcinoma. Gastric (stomach) cancer is cancer that starts anywhere inside the stomach or the stomach wall. Advanced gastric cancer means that a cancer that began in the stomach has spread to at least one other part of the body, such as the liver or lungs. HER2-positive means the cancer cells have too much HER2 protein on the surface of their cells, which can help cancer cells to grow. Advanced or metastatic cancer cannot usually be cured and current treatment aim to control the disease, relieve symptoms, and give patients a better quality of life. Trastuzumab combined with chemotherapy is a current treatment option.
Pembrolizumab is administered by intravenous infusion and works by improving the activity of white blood cells (T-cells) thereby increasing the ability of the immune system to kill cancer cells. Trastuzumab has been designed to attach to HER2 protein which activates cells of the immune system to kill the cancer cells. Early studies have shown benefits of adding pembrolizumab to trastuzumab and chemotherapy in metastatic gastric and gastroesophageal junction cancers, and if licensed, this combination may offer an additional treatment option.