The Chinese National Medical Products Administration (NMPA) has approved Keytruda (pembrolizumab) as a second-line therapy for patients with locally advanced or metastatic esophageal squamous cell carcinoma (ESCC) whose tumors have at least 10% of cells producing the PD-L1 protein.
With the new approval, Keytruda is now available in China for five indications across three different types of cancer. It can be used as a first-line treatment for advanced non-small cell lung cancer and as a second-line treatment for advanced melanoma, the most serious type of skin cancer.
“In China, there is a high incidence of esophageal cancer, and it is the fourth leading cause of cancer-related death,” Jonathan Cheng, MD, vice president of oncology clinical research at Merck Research Laboratories, said in a press release.
“This approval for Keytruda provides an important new option for certain patients with esophageal carcinoma in China, where there have been few treatment advances in recent years,” Cheng said.
Keytruda is an immune checkpoint inhibitor developed by Merck (known as MSD outside the U.S. and Canada) that has been approved both in the U.S. and Europe for the treatment of different types of cancer.
It works by blocking the activity of a protein receptor, called PD-1, that’s found on the surface of immune cells. Treatment with Keytruda prevents the protein receptor from interacting with its signaling molecules, or ligands, called PD-L1 and PD-L2, on cancer cells. This allows the immune cells to recognize and eliminate the cancer cells more efficiently.
The NMPA’s recent approval was based on data from the global KEYNOTE-181 Phase 3 trial (NCT02564263), and from a two-year extension study enrolling only Chinese patients (NCT03933449). The KEYNOTE-181 Phase 3 data also had supported the therapy’s approval in 2019 for the same indication in the U.S.
KEYNOTE‑181 enrolled 628 patients with locally advanced or metastatic ESCC whose disease had progressed while or shortly after receiving first-line therapy for their advanced disease.
During the trial, the participants were randomly assigned to receive either 200 mg of intravenous (into-the-vein) Keytruda every three weeks, or one of three standard chemotherapy agents — paclitaxel, docetaxel, or irinotecan – selected by the study’s investigator.
The study’s main goal was to determine if Keytruda was superior to chemotherapy at extending overall survival in all ESCC patients and in those whose tumors produced PD-L1, corresponding to a combined positive score (CPS) greater than 10.
Data from KEYNOTE‑181 showed that individuals with PD-L1-positive tumors who received Keytruda lived longer than those treated with standard chemotherapy (median 10.3 months vs. 6.7 months). These findings were similar to those obtained in the extension study, which enrolled 123 Chinese patients. That study showed that Keytruda prolonged the time participants lived from 5.4 to 12.0 months in patients with PD-L1-positive tumors.
“The approval for patients with second-line esophageal squamous cell carcinoma marks the fifth indication for Keytruda across three different types of cancer in China,” said Joseph Romanelli, president of MSD in China.
“With each approval, we’ve made steady progress to ensure patients have access to Keytruda, and we will ensure the same for patients who are impacted by esophageal squamous cell carcinoma,” Romanelli added.
