Merck KGaA cancer drug Stimuvax fails late-stage trial FRANKFURT (Reuters) - German drugmaker Merck KGaA's cancer vaccine Stimuvax has failed to meet its goal of improving the survival of lung cancer patients in a late-stage trial. "It is disappointing that the... trial did not meet its primary endpoint, in particular for patients suffering from NSCLC (non-small cell lung cancer)," the trial's coordinating investigator, Frances Shepherd, said in a statement on Wednesday. The trial was testing Stimuvax on more than 1,500 patients with stage III non-small cell lung cancer whose tumors could not be completely removed via surgery and whose disease had at least stabilized following chemoradiotherapy. Merck shares fell 3.5 percent to 98.00 euros in early trade, while Germany's blue-chip DAX index was up 0.2 percent. The news that Stimuvax failed its Phase III trial is also a fresh blow to Oncothyreon Inc, the vaccine's developer. But Merck said it had seen "notable treatment effects" in certain subgroups of patients and would analyse further data on the drug in the coming weeks. It said it would discuss the data with experts and regulatory authorities over the coming months. Stimuvax is one of a number so-called therapeutic cancer vaccines being developed by drug companies to fight tumors by stimulating the body's immune system. The first such vaccine was approved two years ago but Provenge for prostate cancer, made by Dendreon, has met with limited success, due to management missteps and doctors' reluctance to adopt the difficult-to-administer therapy. A number of other cancer vaccines are in development that analysts believe may be more successful, including a product from GlaxoSmithKline against melanoma and lung cancer which is set to report clinical trial results next year. Some investors had already been wary about prospects for Stimuvax after Merck said in March the trial would be continued and final data would be presented later than expected, raising doubts over its success. "Given the history of the drug development with postponements, discontinuations and break-ups we are not surprised about today's outcome," DZ Bank analyst Peter Spengler said. Reporting by Maria Sheahan and Ben Hirschler; Editing by David Cowell