Summary: Teva v. Sandoz has the potential to make a major change in patent law. The basic issue centers on claim construction. Under current law, when a district court’s claim construction is appealed to the Federal Circuit, the appeals court does not defer to the district court’s decisions at all. (This is called de novo review.) Teva is arguing that the Federal Circuit should have to accept any factual determinations that the district court made unless they’re clearly erroneous.