Since the enactment of the America Invents Act, the use of Inter Partes Review (IPR) has steadily gained popularity as a tool for accused infringers to challenge the validity of patents. Although the trend is easing somewhat, to date the final decisions by the Patent Trial and Appeal Board (PTAB) have been overwhelmingly in favor of patent challengers. As a token of hope for patent owners facing the daunting prospects of having their patents invalidated, 35 U.S.C. § 316(d) permits patent owners the ability to file a motion to amend their claims during an IPR. But prior to International Flavors & Fragrances, Inc. v. U.S. Department of Agriculture, IPR2013-00124 (PTAB, May 20, 2014 (Paper 12)), the PTAB had yet to grant a single motion for leave to amend.

37 CFR § 42.121 governs motions to amend during IPR proceedings. Under this rule:

  • the amendments must respond to the grounds of unpatentability raised in the IPR petition
  • the amendments may not enlarge the scope of the claims or introduce new subject matter
  • the motion to amend may only propose a reasonable number of substitute claims (presumed to be only one substitute claim per each challenged claim)
  • the motion to amend must set forth the support in the original disclosure of the patent for each claim that is added or amended

Further constraining the ability for a patent owner to amend its claims during an IPR, the patent owner bears the burden of demonstrating the patentability of any new or amended claims. See Idle Free Systems Inc. v. Bergstrom Inc., IPR2012-00027, slip op. at 7 (PTAB June 11, 2013 (Paper 26)). Accordingly, the PTAB set out the additional requirement that the patent owner “make a showing of patentable distinction over the prior art.” To make this distinction, the PTAB requires the patent owner:

identify specifically the feature or features added to each substitute claim, as compared to the challenged claim it replaces, and come forward with technical facts and reasoning about those feature(s), including construction of new claim terms, sufficient to persuade the Board that the proposed substitute claim is patentable over the prior art of record, and over prior art not of record but known to the patent owner. . . Some representation should be made about the specific technical disclosure of the closest prior art known to the patent owner, and not just a conclusory remark that no prior art known to the patent owner renders obvious the proposed substitute claims.

In the Idle Free final decision, the PTAB expounded that the patent owner must discuss the level of ordinary skill in the art and what would have been known by one with ordinary skill in the art with respect to each added feature of the proposed substitute claims. See Idle Free, IPR2012-00027, slip op. at 33 (PTAB January 7, 2014 (Paper 66)). Under this heavy burden, the PTAB has repeatedly and consistently denied attempts by patent owners to amend their claims during IPR proceedings.

In International Flavors, a patent owner—the U.S. Department of Agriculture (the U.S.)—finally persuaded the PTAB to grant-in-part a motion to amend. There the petitioner challenged claims 1, 4, 5, 7, 8, and 14-26 of U.S. Patent 7,579,016 directed toward the use of isolongifolenone analogs for repelling insects. In particular, one of the prior art references (the Behan reference) disclosed that a variety of perfume ingredients, including isolongifolanone—a particular isolongifolenone analog, could be used to repel mosquitos and cockroaches. Claim 1 claimed the use isolongifolenone analogs in repelling arthropods. Proposed claim 27 was nearly identical to claim 1, except that it limited the isolongifolenone analogs to five compounds previously included as part of a larger Markush group in original dependent claim 8. Proposed dependent claims 28-44 corresponded to original claims 9-26. Proposed independent claim 45 also corresponded to original claim 1, but added the limitation that the arthropods were ticks or mites.

Applying the 37 CFR § 42.121 and Idle Free framework, the PTAB first found that none of the proposed substitute claims impermissibly enlarged the scope of the original claims. Next, the PTAB found that the proposed substitute claims had written description support in the application as filed.

In examining the patentability of the proposed substitute claims, the PTAB reiterated that the patent owner bears the burden of proof to demonstrate patentability of the proposed claims over the prior art in general. With regard to proposed claim 27, the PTAB found the following evidence of patentability persuasive:

  • the U.S. identified the Behan reference as the closest known prior art
  • the U.S. argued that the cited references would not lead one of skill in the art to conclude that the isolongifolenone analogs claimed in proposed claim 27 would have similar properties as the isolongifolanone disclosed in Behan
  • the U.S. provided several publications, as well as an expert declaration, demonstrating the level of ordinary skill in the art
  • the U.S. provided references describing that small changes in the chemical structure for some compounds result in widely different effectiveness in repelling insects
  • the U.S. provided an expert declaration demonstrating that the ordinary artisan would expect that minor structural changes would result in differing repellency

Because dependent claims 28-44 incorporated all of the limitations of claim 27, the PTAB found that they would be patentable as well. But the PTAB also found that the U.S. failed to meet its burden of demonstrating the patentability of proposed substituted claim 45, as applying isolongifolanone as taught by the Behan reference to repel mosquitos and cockroaches would have also inherently repelled ticks and mites. 

While the U.S.’s success in amending its patent in International Flavors provides hope for other patent owners whose patents are subject to an IPR, the hope is somewhat dampened by the fact that petitioner did not oppose the motion to amend, most likely due to the settlement of related litigation. Still, International Flavors provides a roadmap for patent owners seeking to substitute claims during an IPR.