Company: Merck KGaA
2007 Sales: $2.7 billion
Market share: 3.6%
What they have: When Merck KGaA bought out Serono in 2006 it inherited Rebif, a top-selling multiple sclerosis drug. Merck is also one of three companies partnered on cancer drug Erbitux (along with ImClone and Bristo-Myers Squibb, which are not on this list). The drug is approved for head and neck and colorectal cancer.
What to look for: Merck KGaA has filed two additional indications for Erbitux and has a new formulation of Rebif in the works. The company is also cunducting late-stage testing for atacicept, an experimental rheumatoid arthritis treatment.