FRANKFURT, Oct 22: Bayer’s experimental riociguat pill showed promise against a life-threatening form of high blood pressure in the lungs, a potential challenge to existing treatments from Actelion and Gilead <GILD.O>. In a late-stage trial, the drug helped people suffering from pulmonary arterial hypertension (PAH), a progressively worsening condition that can overburden the heart, to better tolerate physical exercise and improve heart function, Bayer said today. (agencies)