"Pivotal trial results for Merck  Co Incs immunotherapy drug Keytruda show that it lengthened survival by three months or nearly  percent for patients with advanced bladder cancer who had stopped responding to chemotherapy.  The data to be presented next month at a meeting of the American Society of Clinical Oncology follow last weeks announcement that rival drug Tecentriq from Roche Holding AG did not improve survival when used as a secondline treatment for bladder cancer in a trial.  The Merck drug is awaiting U.S. Food and Drug Administration approval but Tecentriq was approved by the agency last year contingent on verification of its clinical benefit. Roche in an emailed statement said it plans to discuss the data with health authorities but did not disclose the timing for the discussions. According to the FDA approval letter the company has until December to submit the full trial data to the agency.  Merck filed in February for FDA approval of Keytruda for both initial and secondary treatment of advanced urothelial cancer the most common type of bladder cancer. Keytruda is already approved for treating melanoma lung cancer head and neck cancer and Hodgkin lymphoma.  Merck announced in October that the secondline bladder cancer study met its main goal and was stopped early. The company is currently enrolling patients in a phase three trial of Keytruda combined with chemotherapy as an initial treatment for bladder cancer.  In addition to Tecentriqs approval for bladder cancer patients whose disease has stopped responding to chemotherapy the FDA last month approved the Roche drug as an initial treatment for people with a specific type of advanced bladder cancer and in people whose cancer progressed despite at least one prior platinumcontaining chemotherapy.  The agency has also granted contingent approval to AstraZeneca Plcs Imfinzi BristolMyers Squibbs Opdivo and Bavencio developed by Pfizer Inc and Merck KGaA as secondline bladder cancer treatments.  All five drugs are part of a new class of treatments designed to unleash the bodys immune system to fight cancer by interfering with proteins known as PD or PDL that help malignant cells evade immune attack.  Merck said data from an openlabel Phase  trial of  advanced bladder cancer patients showed median survival of . months for Keytruda patients and . months for patients given secondline chemotherapy. The studys median followup was . months.  After  months  percent of Keytruda patients were alive compared with . percent of chemotherapy patients according to research published by ASCO.  The study did not detect a difference in the length of time patients lived without their disease getting worse.  Severe side effects were reported in . percent of the Keytruda patients compared with nearly half of the chemotherapy group.  Reporting By Deena Beasley Editing by Bill Rigby and David Gregorio Our StandardsThe Thomson Reuters Trust Principles. httpthomsonreuters.comenaboutustrustprinciples.html"