Merck & Co – known as MSD outside the US and Canada – has announced that Keytruda (pembrolizumab) has been approved by the US Food and Drug Administration (FDA) as part of a combination treatment for certain gastric cancer patients.
The anti-PD-1 therapy can now be used alongside fluoropyrimidine- and platinum-containing chemotherapy for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma.
The FDA’s decision was supported by results from the late-stage KEYNOTE-859 trial, in which the Keytruda/chemotherapy combination reduced the risk of death by 22% compared to chemotherapy alone for these patients.
Median overall survival was 12.9 months in the Keytruda plus chemotherapy cohort compared to 11.5 months for those receiving chemotherapy alone.
An estimated 26,500 people in the US will be diagnosed with gastric cancer in 2023. Up to 95% of cases are adenocarcinomas, which develop from cells in the innermost lining of the stomach, and the majority of gastric cancers are HER2-negative.
Additionally, as the disease tends to develop slowly over many years and rarely causes early symptoms, more than 70% of patients are diagnosed at an advanced stage.
Merck’s Keytruda works by enhancing the ability of the body’s immune system to help detect and fight tumour cells.
The FDA’s decision marks the seventh gastrointestinal cancer indication for Keytruda-based regimens and the 38th indication for the therapy in the US.
Dr Marjorie Green, senior vice president and head of late-stage oncology, global clinical development, Merck Research Laboratories, described the latest Keytruda approval as “an important milestone for patients with advanced HER2-negative gastric or GEJ adenocarcinoma”.
Beyond gastric cancer, Keytruda holds approvals to treat a wide variety of cancers, including specific cases of bladder cancer, melanoma and Hodgkin’s lymphoma.
Last month, the therapy was approved in the US as part of a combination treatment for patients with earlier stages of lung cancer.
The approval specifically applies to patients with resectable non-small cell lung cancer and means that Keytruda can now be used in combination with platinum-containing chemotherapy as a neoadjuvant therapy to prepare patients for the surgical removal of their tumour and then as a single agent as an adjuvant treatment after surgery.