Biotie Therapies Oyj, of Turku, Finland, said it has begun marketing of a proposed U.S. public offering of $50 million American depositary shares (ADSs). The company plans to use net proceeds from the offering, together with a portion of its current liquid assets, to fund a phase III double-blind trial (and extension study) of its Parkinson's disease drug, tozadenant (SYN115).