Post Grant Review (PGR) petitions are on the rise, and nearly half of all petitions to date have challenged patents in Biotechnology and Organic Chemistry, or Chemical and Materials Engineering technology centers. We have reviewed PGR petitions filed against patents in these technology categories. One final written decision issued on Nov. 14, 2016, and more are expected in the coming weeks and months. We see this moment as an opportunity to summarize some of the key trends and likely impacts of PGRs in the chemical and life sciences.
To date, 12 PGR petitions have been filed against chemical and life sciences patents. Of these, five petitions were denied and seven were instituted. Among instituted cases, four included successful institutions based on anticipation (one of which was based on public use), five included successful institutions based on obviousness, and four included successful institutions based on written description, enablement, or indefiniteness. One case asserted subject matter eligibility as a grounds of invalidity, but that lone § 101 challenge was not instituted.
Petitioner Standing in PGR
A threshold issue in institution decisions is whether the patent is eligible for PGR.,  According to Patent Trial Appeal Board (PTAB) rules, the petitioner must “certify” that the patent is PGR-eligible. Exactly what is meant by “certification” is not clear in every case.
Under America Invents Act (AIA) section 3(n)(1), a patent is PGR-eligible if it contains or contained at any time a claim subject to AIA first-inventor-to-file (FITF) provisions (and meets other PGR requirements). Applications filed after March 16, 2013 that do not have any benefit claims to an effective filing date prior to March 16, 2013 are FITF applications eligible for PGR. Eligibility in these cases is straightforward, and simple “certification” by the petitioner should suffice.
However, applications filed after March 16, 2013 that do have at least one claim with the benefit of an effective filing date prior to March 16, 2013 are “transition applications.” These patents may or may not be eligible, depending on whether the claims find written description and enablement support in the earlier-filed (pre-AIA) priority application.
In order for a petitioner to establish that a patent that issued from a transition application is eligible for PGR, the PTAB requires a persuasive showing (considerably more than mere “certification”) that the application contains or contained at any time a claim that was subject to FITF provisions. To show that a claim in a transition application is subject to FITF provisions, the petitioner must show that “the patent contains, or the corresponding application contained at any time, at least one claim that was not disclosed in compliance with the written description and enablement requirements of § 112(a) in the earlier application for which the benefit of an earlier filing date prior to March 16, 2013 was sought.”
The picture is muddled by the fact that the AIA requires that a PGR petitioner “shall have the burden of proving a proposition of unpatentability by a preponderance of the evidence.” And in order to institute PGR in the first place, the petitioner must establish that “it is more likely than not that at least 1 of the claims of the challenged patent is unpatentable.” The PTAB has referred to all of these burdens in determining whether patents are eligible for PGR, though it has not explicitly stated the standard it applies.
In some cases, the Board has simultaneously addressed § 112 eligibility and § 112 patentability issues, applying the “more likely than not” standard to both. Inevitably, the requirement to certify eligibility is subsumed by the need to establish unpatentability as more likely than not.
The bottom line for transition application patent owners is that they must be prepared with strong enablement and written description arguments in order to overcome a petitioner’s assertion that the patent is PGR-eligible. A strong showing of enablement and written description support in the earlier-filed priority application will often hinge on:
(i) data in the earlier-filed application clearly demonstrating enablement;
(ii) articulation of how analysis of the Wands factors favors enablement;
(iii) a clear description in the specification of each element in the claims; and
(iv) congruence of the scope of claims and scope of disclosure in specification.
This is especially important for patent owners because in every case we analyzed where the Board assessed § 112-based eligibility, the Board agreed with the petitioner that the priority application lacked § 112 support and therefore the patent was eligible for PGR. In each of these cases, successfully refuting the petitioner’s assertions of eligibility would have cut off the proceeding at the pre-institution stage. With trials underway in all of these cases, and more petitions expected, it remains to be seen how important the strategy of refuting eligibility will be for patent owners undergoing PGR.
 Brian C. Kwok, Nicholas V. Martini and Nicole Johnson, “An Update on Post Grant Review Filings and Decisions” law360, Nov. 2, 2016, 12:05 p.m. EDT, https://www.law360.com/articles/858429/an-update-on-post-grant-review-filings-and-decisions.
 All PGR institution decisions were reviewed for patents within National Bureau of Economic Research technology categories “Chemical” (and all subcategories) and “Drugs and Medical” (and all subcategories).
 Altaire Pharmaceuticals Inc. v. Paragon Bioteck Inc., Case PGR2015-00011 (PTAB Nov. 16, 2015) (Paper 48).
 US Endodontics LLC v. Gold Standard Instruments LLC, Case PGR2015-00019 (PTAB Jan. 29, 2016) (Paper 17) at 9-12 [hereafter PGR2015-00019].
 Out of 12 PGRs analyzed, seven included a § 112 eligibility analysis. In four of the 12 cases, a § 112 inquiry was not required for eligibility because the patents at issue did not claim priority to pre-AIA effective filing dates. In one case, the patent was summarily deemed ineligible because it had an issue date prior to March 16, 2013. Out of the seven cases in which the PTAB undertook a § 112 eligibility analysis, all seven were found eligible for lack of written description or enablement in the priority application.
 37 C.F.R. § 42.204(a).
 See 35 U.S.C. § 321-22.
 Inguran LLC v. Premium Genetics (UK) Ltd., Case PGR 2015-00017 (PTAB Dec. 22, 2015) (Paper 8) at 9-18 [hereafter PGR2015-00017].
 Id. at 10-11.
 35 U.S.C. § 326(e).
 35 U.S.C. § 324(a).
 See PGR2015-00019 at 11-12.
 See, e.g., PGR2015-00019 at 17.
 See, e.g., PGR2015-00017 at 18 (assessing enablement for purposes of unpatentability) (citing In re Wands, 858 F.3d 731, 737 (Fed. Cir. 1988)).
 See, e.g., Dr. Reddy’s Labs Ltd. v. Helsinn Healthcare S.A., Case PGR2016-00008 (PTAB Aug. 17, 2016) (Paper 11) at 12-13.
 Arkema Inc. v. Honeywell Int’l Inc., Case PGR2016-00012 (PTAB Sept. 2, 2016) (Paper 13) at 19.