Shares of NewLink Genetics Corp. plunged 37 percent in extended trading on Monday after the drug maker said its experimental pancreatic cancer immunotherapy did not help patients live longer in a late-stage trial, Reuters reported. The Ames-based company was testing its drug, algenpantucel-L, in combination with standard-of-care therapy, against standard treatment alone, in 722 patients with surgically removed cancer. There was no statistically significant difference between the two groups in terms of overall survival, NewLink said. The company will focus on its other pipeline opportunities, CEO Charles Link said in a statement.