MedImmune, Inc. v. Genentech, Inc., 549 U.S. 118 (2007), was a decision by the Supreme Court of the United States involving patent law. It arose from a lawsuit filed by MedImmune which challenged one of the Cabilly patents issued to Genentech. One of the central issues was whether a licensee retained the right to challenge a licensed patent, or whether this right was forfeited upon signing of the license agreement. The case related indirectly to past debate over whether the US should change to a first to file patent system - in 2011, President Obama signed the Leahy-Smith America Invents Act, which shifted the United States to a first-inventor-to-file patent system.