Additional Relevant Details AbbVie is trying to protect a rheumatoid arthritis injection whose sales surged 17 percent in the second quarter to $4.15 billion. The drug accounted for 61 percent of AbbVie’s 2015 revenue. The litigation is only part of the hurdle for Amgen. The Thousand Oaks, California-based biotech company has to navigate a byzantine series of steps known as the “patent dance” that’s still being worked out by U.S. courts and regulators.