Hedge Your Bets in TC 1600 PGRs
Post grant reviews (PGRs) have proven to be more popular in the biotechnology space (TC 1600) than any other art unit, with 42—or 28.1%—of the PGRs filed to date classified as TC 1600 patents. By way of comparison, TC 1600 makes up just 10.1% of all IPRs filed to date. Perhaps not surprisingly, PGRs are appealing for challengers of biotechnology patents because written description, enablement, and indefiniteness can all be raised, and these § 112 hurdles tend to be more challenging in the unpredictable arts of TC 1600.
Challengers generally attempt to maximize their chances by alleging grounds based on both prior art and § 112. Indeed, 73% of TC 1600 PGRs include both types of grounds, while 14.6% raise only prior art, and 12.2% include only § 112 grounds.
The importance of hedging your bet by including multiple types of challenges is illustrated in the final written decision in PGR2017-00022, where the Board found that Grünenthal’s petition rendered all claims in Antecip’s U.S. Patent No. 9,408,862 unpatentable.
The ’862 patent, covering oral pharmaceutical compositions containing zoledronic acid, was challenged in multiple ways, with each claim attacked by at least one prior art ground as well as one § 112 ground. And, this approach proved essential. Several pages of the final written decision are dedicated to determining whether one of Grünenthal’s references—a conference poster—qualified as prior art. Grünenthal argued that the poster was publicly presented and available to the public well before the priority date, but Antecip argued that Grünenthal had not provided sufficient evidence to show that it qualified as prior art.
The Board ultimately agreed, holding that Grünenthal’s corroborating evidence was untimely as it was included in the Reply rather than in the Petition. But even if this evidence was considered, the Board held that Grünenthal “has not met its burden of establishing that the [poster] qualifies as prior art.” Specifically, the Board held that Grünenthal presented “no meaningful evidence or related discussion suggesting that the [poster] was displayed in a manner that would have allowed interested and ordinarily skilled artisans exercising reasonable diligence to locate the poster.” Thus, this reference was not considered in the two grounds it was used.
Because this reference was not used, a handful of claims were only held unpatentable on lack of enablement grounds, leaving open the possibility to save some claims on appeal—particularly because one judge dissented from the enablement finding.
This decision provides a clear lesson from the PTAB: all evidence necessary to prove that key art relied upon actually qualifies as prior art must be presented in a petition. Luckily for Grünenthal, they had a back-up enablement argument that saved the day.
 For an up-to-date listing of all PGRs and IPRs filed in TC1600, visit Oblon’s TC 1600 Post Grant Library, available at https://www.oblon.com/ptab-proceedings/tc-1600-post-grant-library/.