By Kevin E. Noonan — The Leahy-Smith America Invents Act prescribed two very different post-grant review proceedings in U.S. patent law. The first, post-grant review (PGR), had some analogies with European opposition practice, in that petitions for PGR could be filed no later than nine months after the patent had granted and any ground of patentability was available as the basis for challenge (see 35 U.S.C. § 321 et seq.). The other proceeding, inter partes review (IPR), was available throughout an unexpired patent term but the subject matter of challenge was limited to anticipation under 35 U.S.C. § 102 and…
