Bayer HealthCare today announced that the U.S. Food and Drug Administration's (FDA) Office of Orphan Products Development has granted two separate orphan drug designations for its investigational, oral medication riociguat, proposed trade name Adempas®, for the treatment of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). The Orphan Drug Designation program provides orphan status to drugs and biologics that are defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases and disorders that affect fewer than 200,000 people in the U.S., or that affect more than 200,000 persons but are not expected to recover the costs of developing and marketing a treatment drug.