John C. Paul
Finnegan, Henderson, Farabow, Garrett & Dunner, LLP

D. Brian Kacedon,
Finnegan, Henderson, Farabow, Garrett & Dunner, LLP

When drafting a patent license agreement, licensors often want to include provisions prohibiting the licensee from challenging the validity of the patents involved or shifting the burden of proof for infringement, requiring that the licensee prove noninfringement. The enforceability of these provisions often turns on whether clear and unambiguous language indicates the intent of the parties. This is particularly the case for provisions seeking to bar validity challenges as such provisions may run afoul of the Supreme Court’s decision in Lear v. Adkins, which overruled the doctrine of “licensee estoppel.”