Abbott's dealmaking produced Humira, which accounts for 15% of corporate revenue and is Abbott's biggest product. Second-quarter sales of $1.1 billion jumped 48% vs. the year-ago quarter. Humira was an experimental compound when Abbott acquired it via its $6.9 billion purchase of Knoll Pharmaceuticals from Germany's BASF in 2001. Humira reached the U.S. market in 2003 as an injectable treatment for rheumatoid arthritis. It has since gained approval from the Food and Drug Administration for psoriasis, the gastrointestinal ailment Crohn's disease and three other diseases. Abbott expanded its heart-disease business thanks to the 2006 acquisition of Kos Pharmaceuticals. At the time, Abbott only had TriCor, which lowers triglyceride levels. Triglyceride is a form of fat which, like bad cholesterol, increases the risk of heart disease. Abbott paid $3.7 billion for Kos and got three cholesterol drugs, including Niaspan, which is an extended-release version of the vitamin niacin. Niaspan lowers bad cholesterol and raises good cholesterol. So does Advicor, which combines Niaspan and generic Mevacor, a bad-cholesterol drug from Merck ( MRK). When Abbott bought Kos, Merck was testing a drug that combines extended-release niacin and a compound designed to produce fewer side effects than Niaspan and Advicor. Abbott's drugs cause flushing, or the reddening of the skin especially around the face and neck. However, in April 2008, the FDA rejected the Merck drug called Cordaptive. The agency wanted to see more safety and efficacy data, telling Merck to reapply after results of an ongoing clinical trial are released in early 2013. Merck is talking to the FDA about providing data that would enable an earlier review.