In an intriguing turn of events, the US Court of Appeals for the Federal Circuit made a decision that has unnerved parts of the legal world. The Court deduced in Actelion Pharms. Ltd v. Mylan Pharms. Inc., Case No. 22-1889 (Fed. Cir. Nov. 6, 2023) that the constraint of “a pH of 13 or higher” was not decodable just by employing the asserted patents’ intrinsic evidence.
Such a development propels the case back to the district court, with directions to deliberate on the consideration of extrinsic evidence and its repercussion on claim construction. The judicial statement brings a significant question to the fore – whether resorting to extrinsic evidence is necessary when intrinsic evidence is muddied. This question carries serious implications for the legal professionals navigating the complex labyrinths of patent law.
Jurists often underscore the fundamental concept of relying on intrinsic evidence whenever possible in patent claims. The premise holds that it is better to base interpretations on intrinsic records, which come directly from the patentee. However, should these records fail to provide clarity, it is only logical to consider the introduction of extrinsic evidence.
Extrinsic evidence refers to all information that is not literally contained in the patent’s specification or prosecution history. This might be dictionaries, treaties, expert testimonies and more, all of which could be utilized to interpret a patent claim when the intrinsic evidence is far from clear.
The Actelion case makes clear that the ambiguity in intrinsic evidence paves the way for considering extrinsic evidence. Consequently, it places extrinsic evidence in a definitive position within claim interpretation when primary intrinsic records don’t quite hit the mark. It serves as a crucial clarion call for legal experts, hinting at broader acceptability to integrate external documents and testimonies, especially under conditions where the intrinsic information is enshrouded in uncertainty.
Given these developments, it is imperative that legal professionals keep a careful eye on evolving case law and remain nimble in their applications of extrinsic evidence in interpretation and claim construction. The nuanced understanding and skillful use of such evidence could well be the game-changer in high-stakes patent disputes.