The focus of Merck's current pharmaceutical R&D is on oncology and cardio-metabolic care. In the former therapeutic area, its first marketed product is Erbitux (cetuximab), for which it has marketing rights worldwide, apart from North America. (Cetuximab was discovered by Imclone Systems, and is marketed in North America by Bristol-Myers Squibb.) Other products from Merck include Metformin, Bisoprolol, Levothyroxine and Digitoxin.