Rise In Generic Competition For Animal Drugs Could Result In PTAB Seeing Green

Much like the Hatch-Waxman Act created an abbreviated pathway for generic manufacturers of human drugs to enter the market, The Generic Animal Drug and Patent Term Restoration Act (“GADPTRA”) provides a framework for sponsors of pioneer veterinary drugs to enjoy a period of regulatory exclusivity before giving generic animal drug makers a chance for earlier market entry by filing an Abbreviated New Animal Drug Application (“ANADA”) and successfully challenging the pioneer’s “Green Book”-listed patents in district court litigation.

Most approved animal drugs do not have a generic version, so it’s not surprising that we haven’t seen many district court litigations concerning generic animal drugs. See, e.g., Metacam®; Baytril®; Frontline®. But a number of companies, such as Putney Inc., are now developing generic animal drugs as demand rises. On the human side, we continue to see Orange Book-listed patents and related patents challenged in IPR proceedings in various contexts. See, e.g., IPR2013-00024 (non-litigant petitioner, settled); IPR2013-00368 (first-filer); IPR2014-00115 (paragraph III patent); IPR2014-00559 (non-OB metabolite patent challenged during regulatory exclusivity); IPR2014-00651-56 (brand petitioner); IPR2014-01126 (select ANDA-defendant petitioners); IPR2015-00005-00008 (corporate entity raises real-party-in interest questions); IPR2015-000547; IPR2015-00561-562 (non-litigant petitioner); IPR2015-00720, IPR2015-00817, IP2015-00988 (Coalition for Affordable Drugs petitioner); IPR2015-00903-902; IPR2015-01490.

A growing animal health market, the reauthorization of the Animal Generic User Fee Act, and consumer demand for generic competition portends a new era for animal drug patent challenges. A number of factors could motivate this growing number of generic animal drug manufacturers to seek PTAB trials over district court litigation, including a fast (12-18 month) timeline; lower costs, limited discovery, and lack of live testimony; lower burdens of proof; and a high Rule 36 affirmance rate at the Federal Circuit. See, e.g., Merial Limited v. Virbac, IPR2014-01279 (Frontline®).

By filing a preliminary response, patent owners have the chance to point out defects in the petition that may result in the PTAB denying institution. Preliminary responses, however must be filed within three months and cannot include new declaration evidence, i.e., a responsive expert declaration. Thus, it is important for pioneer drug patentees anticipating PTAB challenges to prepare in advance, i.e., by drafting specifications that provide a strong basis for desired claim constructions, considering whether to file declaration evidence during prosecution, and engaging experts in advance.