The University of Iowa and University of Iowa Research Foundation (UIRF) are suing Amgen, of Thousand Oaks, California, for patent violation. According to the complaint, Amgen and its affiliates “have for many years infringed the Iowa Patents with full knowledge of them” to produce Enbrel (etanercept) and Vectibix (panitumumab). UIRF-owned patents 5,168,062 and 5,385,839, filed in 1992 and 1995, respectively, protect the human cytomegalovirus promoter—a key regulatory sequence used to increase protein expression and enhance the production of biologic therapeutics. Enbrel, a recombinant fusion protein that blocks tumor necrosis factor, is used to treat rheumatoid arthritis and psoriasis, and generated $1.69 billion in US sales for Amgen in the first half of 2008. Vectibix, a monoclonal antibody used to treat colon cancer, generated $57 million over the same period. Amgen has ignored entreaties to license the technology, the complaint also states. Michael Shuster, a patent attorney for Mountain View, California–based Fenwick & West, says the case may have only been filed now, despite years of alleged patent violations, because the university was “probably trying to negotiate a license with Amgen and trying to establish a successful licensing record.” UIRF has granted 113 active licenses for these patents. Immunex, a subsidiary of Amgen, also located in Thousand Oaks, California, is a co-defendant in the case. Amgen denies any wrong-doing.