Biopharma stalwart Amgen Inc. maintained its slow-but-steady growth for the fourth quarter and full year 2013, beating consensus estimates and offering conservative guidance for 2014 as investors await key pipeline milestones, including the possible new drug application filing for evolocumab, its anti-PCSK9 drug in a tight race with Sanofi SA and Regeneron Pharmaceuticals Inc. in the blockbuster cardiovascular space.