China Approves Merck's Keytruda for First-Line HER2+ Advanced Gastric Cancer

On June 25, 2024, Merck, a global pharmaceutical leader, announced that its PD-1 inhibitor pembrolizumab (marketed as Keytruda®) received approval from the China National Medical Products Administration (NMPA). This approval permits the use of pembrolizumab in combination with trastuzumab and chemotherapy containing fluoropyrimidine and platinum for the first-line treatment of patients with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma. The treatment is specifically for tumors expressing PD-L1, identified by a Combined Positive Score (CPS) of 1 or higher, based on a validated test.

This new indication approval is largely due to the promising results from Merck's extensive global Phase III clinical trial, known as KEYNOTE-811.

Gastric cancer is a major health concern globally, with particularly high prevalence in China, where the incidence and mortality rates are significantly elevated. The World Health Organization (WHO) reports around 358,000 new gastric cancer cases and approximately 260,000 related deaths annually in China. The vast majority, over 95%, are adenocarcinoma cases, highlighting the critical need for effective treatment and prevention strategies.

However, early detection of gastric cancer in China remains a significant challenge, with only about 20% of cases identified at an early stage. This leads to most patients being diagnosed at advanced stages, complicating treatment efforts. Furthermore, the prognosis for advanced gastric cancer patients is bleak, with a 5-year survival rate of less than 10%, underscoring the urgent need for new therapeutic options.

In light of these challenges, the approval of pembrolizumab (Keytruda®) offers new hope for gastric cancer patients. Pembrolizumab, an immune checkpoint inhibitor, works by blocking the tumor's ability to evade the immune system, thus enabling the patient's immune system to target and destroy cancer cells more effectively. The KEYNOTE-811 clinical trial demonstrated that the combination of pembrolizumab with other chemotherapy agents resulted in significant efficacy and safety, providing a promising new treatment strategy for those afflicted by gastric cancer.

The approval of this new indication for pembrolizumab represents a substantial step forward in the treatment of gastric cancer in China. It also highlights Merck's ongoing commitment and capability as a leading global pharmaceutical company. With continued research and clinical application, pembrolizumab is expected to play an increasingly significant role in the management of gastric cancer, offering renewed hope to many patients battling this challenging disease.