Merck's Keytruda extends lung cancer survival in two trials

By Deena BeasleyCHICAGO (Reuters) - Merck & Co's immunotherapy Keytruda improved survival as a stand-alone treatment for newly-diagnosed lung cancer patients and with chemotherapy for hard-to-treat squamous cell lung cancer, new data released on Sunday showed, further cementing the company's lead in the most lucrative oncology market.Keytruda is competing with drugs from Roche,Bristol-Myers Squibb and others that also unleash the body’s immune system to attack tumors for dominance in l