On October 4, 2017, the Federal Circuit provided some relief to patent owners by holding that petitioners seeking to cancel patent claims through inter partes review proceedings (“IPRs”) under the Leahy-Smith America Invents Act (“AIA”) bear the burden of showing invalidity when the patent owner attempts to amend its patent claims. Specifically, in Aqua Products, Inc. v. Matal (Case No. 2015-1177, Oct. 4, 2017), the court considered whether 35 U.S.C. § 316(e) of the AIA places the burden of proving a proposition of unpatentability with regard to claim amendments authorized by 35 U.S.C. § 316(d) onto the petitioner in an IPR and whether the Patent Trial and Appeal Board’s (“Board”) practices accord with that application. After an extensive review of the statutory scheme and legislative history, the court concluded “that § 316(e) unambiguously requires the petitioner to prove all propositions of unpatentability, including for amended claims.” Patent owners, who have been under the deluge of AIA IPR reviews over the past four years, breathed a collective sigh of relief. The decision comes only seven weeks ahead of oral arguments scheduled at the U.S. Supreme Court in Oil States Energy Services, LLC v. Greene’s Energy Group, LLC, where the Court will consider the constitutionality of the entire AIA process.