Merck, known as MSD outside the United States and Canada, today announced that the pivotal phase 3 KEYNOTE-061 trial investigating KEYTRUDA^® (pembrolizumab), the company’s anti-PD-1 therapy, as a second-line treatment for patients with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma, did not meet its primary endpoint of overall survival (OS) (HR, 0.82 [95% CI, 0.66-1.03]; p=0.042 [one-sided]) in patients whose tumors expressed PD-L1 [Combined Positive Score (CPS) ≥ 1]. Additionally, progression free survival (PFS) in the PD-L1 positive population did not show statistical significance. The safety profile observed in KEYNOTE-061 was consistent with that observed in previously reported studies of KEYTRUDA; no new safety signals were identified.

In September 2017, the U.S. Food and Drug Administration (FDA) approved KEYTRUDA as a third-line treatment for previously treated patients with recurrent locally advanced or metastatic gastric or gastroesophageal junction cancer whose tumors express PD-L1 (CPS ≥ 1) as determined by an FDA-approved test, with disease progression on or after two or more prior lines of therapy including fluoropyrimidine- and platinum-containing chemotherapy and if appropriate, HER2/neu-targeted therapy.

The current indication remains unchanged and we continue to evaluate KEYTRUDA for gastric or GEJ adenocarcinoma through KEYNOTE-062, a phase 3 clinical trial studying KEYTRUDA as a monotherapy or in combination with chemotherapy as first-line treatment for patients with PD-L1 positive advanced gastric or gastroesophageal junction cancer, and with KEYNOTE-585, a phase 3 trial studying KEYTRUDA (pembrolizumab) in combination with chemotherapy in a neoadjuvant/adjuvant setting.

“We remain committed to the continued study of KEYTRUDA for gastric cancers and finding new options for patients facing this difficult-to-treat cancer type across various treatment settings,” said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. “We want to thank the patients and investigators for their participation in this study and we look forward to sharing the full results from KEYNOTE-061, which will provide the medical community with important information about how patients with gastric cancer whose tumors express PD-L1 respond to treatment.”

About KEYNOTE-061

KEYNOTE-061 is a randomized, open-label, pivotal phase 3 study (ClinicalTrials.gov, NCT02370498) investigating KEYTRUDA as a monotherapy versus paclitaxel in patients with advanced gastric or GEJ adenocarcinoma whose disease progressed after first-line treatment with platinum and fluoropyrimidine doublet therapy. The primary endpoints are PFS and OS in patients whose tumors express PD-L1 (CPS > 1); secondary endpoints include PFS, OS and Overall Response Rate (ORR) in patients regardless of PD-L1 expression. The study randomized 592 patients to receive KEYTRUDA (200 mg fixed dose every three weeks) or paclitaxel [80 mg/m^2 on Days 1, 8, and 15 of each 28-day cycle].

The study was designed to first evaluate efficacy in patients whose tumors expressed PD-L1. If efficacy signals were observed and PFS and OS were positive in this subset of patients, further analysis was planned in the overall population.

About Gastric Cancer

Gastric cancer, also called stomach cancer, is a type of cancer that begins in the stomach and tends to develop slowly over many years. Most gastric cancers are adenocarcinomas, which develop from the cells of the innermost lining (mucosa) of the stomach. Risk factors for gastric cancer include gender, age, ethnicity, geography and infection with Helicobacter pylori. Worldwide, gastric cancer is the fifth most common type of cancer and the third leading cause of cancer death. Each year there are approximately 952,000 newly diagnosed cases of gastric cancer resulting in approximately 723,000 deaths worldwide. It is estimated that in 2017, more than 10,000 people will die from gastric cancer in the U.S. alone.

About KEYTRUDA^® (pembrolizumab) Injection 100 mg

KEYTRUDA (pembrolizumab) is an anti-PD-1 therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.

Merck has the industry’s largest immuno-oncology clinical research program, which currently involves more than 650 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient’s likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.

資料來源：https://www.businesswire.com/news/home/20171214006395/en/Merck-Update-KEYNOTE-061-Phase-3-Study-KEYTRUDA%C2%AE