It’s been quite a year for Mallinckrodt (MNK). In March 2014, it acquired Cadence Pharmaceuticals, the maker of the pain medication Ofirmev, for $1.4 billion. Then, in August, came the $5.6 billion acquisition of Questcor Pharmaceuticals, maker of the market-leading immune system treatment Acthar. In November, the Food and Drug Administration threw a regulatory roadblock in front of Mallinckrodt’s ADHD treatment, gConcerta.