Merck KGaA MKGAF, -0.36% and Pfizer PFE, -0.91% said Friday that a late-stage clinical trial testing Bavencio as a first-line maintenance treatment for patients with certain forms of gastric cancer failed to meet the study’s primary endpoints for survival. The current standard of care is chemotherapy. The German drugmaker and Pfizer formed an alliance in 2014 to develop and commercialize Bavencio, which was first approved by the U.S. Food and Drug Administration in 2017 as a treatment for metastatic Merkel cell carcinoma. Shares of Pfizer have fallen 15.44% year-to-date, while the S&P 500 SPX, +0.27% is up about 23% for the year.