Bayer says lung drug shows promise in prolonged trial FRANKFURT (Reuters) - Bayer said extended use of its experimental riociguat pill to treat a life-threatening form of high blood pressure in the lungs was shown to be safe and effective in a prolonged trial. In the extension of a late-stage trial, the drug was shown to help people suffering from pulmonary arterial hypertension (PAH), a progressively worsening condition that can overburden the heart, to better tolerate physical exercise. It said that side effects, including headache, dizziness, indigestion and low blood pressure, were tolerable. Bayer has said it expects peak annual sales of more than 500 million euros ($646 million) from the product and analysts polled by Thomson Reuters Pharma on average see 2017 sales from riociguat of $679 million, posing a potential challenge to existing treatments from Actelion and Gilead. Preliminary results of the study were published in October, encouraging Bayer to earlier this year submit riociguat for regulatory approval in the United States and Europe. Reporting by Ludwig Burger and Frank Siebelt; Editing by Toby Chopra