US Legal and Regulatory Update

This article presents an overview of Pfizer v. Sanofi Pasteur, a decision that continues the recent trend of Court of Appeals for the Federal Circuit (CAFC) toward tighter scrutiny of patent claims. The CAFC reaffirmed that an expectation of success in combining and modifying prior art need only be reasonable, not absolute. The results of Pfizer highlights a continued drift by the PTAB and courts toward stricter scrutiny of patent claims, both during prosecution of the claims and during later litigation of the claims. Such claims may be somewhat more difficult to procure, and more open to later invalidation during litigation.