On Tues., Sept. 18, 2012, in Medtronic Inc. v. Boston Scientific Corp. et al., Nos. 2011-1313, -1372, the Federal Circuit (Lourie, Linn, and Prost) determined the proper allocation of the burden of proof as to patent infringement issues in the limited circumstance where a party licensed to a patent-in-suit seeks a declaratory judgment of non-infringement.  The Court held that where the only issue is the request by the licensee for a declaratory judgment of non-infringement, the licensee bears the burden of persuasion to show non-infringement, as any counterclaim for infringement is foreclosed by the existence of a license agreement.

[UPDATE]  On May 20, 2013, the U.S. Supreme Court has granted Medtronic’s Petition for Certiorari, and will review this case.  For more coverage on the status of this case at the Supreme Court level, you can check out SCOTUSblog. [/UPDATE]

Although the general rule is that the patentee bears the burden of proving patent infringement, the unique circumstances of this case and the Supreme Court’s decision in MedImmune, Inc. v. Genentech, Inc., 549 U.S. 118 (2007) mandated a different result here.  In MedImmune, the Supreme Court ruled that a patent licensee need not terminate its license before filing a declaratory judgment action challenging the validity of the licensed patent or the scope of the license agreement (i.e., whether the licensed conduct would infringe but for the license).   While a claim for declaratory judgment of non-infringement normally triggers a compulsory counterclaim for infringement, the existence of a license precludes such a claim.  In Medtronic, therefore, the Court held that where the only relief sought is a declaratory judgment of non-infringement, the licensee that files a declaratory judgment action bears the burden of persuasion of non-infringement.