The U.S. Supreme Court last week rejected the Federal Circuit Court of Appeals’ practice of reviewing all district court claim-construction rulings upon appeal. The Teva Pharmaceuticals v. Sandoz ruling, which says that the facts on which claim constructions are based can only be discarded if they contain obvious errors, reverses a 16-year-old rule that has been a source of controversy in the world of patent litigation.

The Recorder reports the decision will likely lead to the use of more expert evidence in district court proceedings, referred to as Markman proceedings in a reference to the 1996 case in which the Supreme Court last set the rules of claim construction. IP Litigation partner William Atkins echoed that, while claim construction generally remains unchanged, Markman proceedings will become more critical to the process of patent litigation.

"The Teva decision is a ground shift, but not a true earthquake,” Atkins told Law360. “The district court has now been given deference on factual issues while much of claim construction remains a matter of law. Markman proceedings just became even more important and more expensive, as the strategic question will be whether to use an expert there or not.”