Inter Partes Review (“IPR”) has proven to be a popular tool for patent infringement defendants . Among the petitioner-friendly features of IPR is the limited ability for patent owners to amend the challenged claims. For example, during inter partes reexamination, patent owners were allowed to present an unlimited number of amended and new claims as a matter of right. As such, accused infringers often feared that patent owners could amend around the best prior art and leave the reexamination in a stronger position than before. In contrast, patent owners in IPR proceedings must file a motion to amend the challenged claims and, in most circumstances, may present “only one substitute claim ... to replace each challenged claim.”1
In addition to the procedural hurdles, the United States Patent and Trademark Office Patent Trial and Appeal Board (“PTAB”) has set a high bar for patent owners to overcome in order to amend claims challenged in an IPR trial.2 In fact, the PTAB’s recent decision in International Flavors & Fragrances, Inc. v. U.S. Department of Agriculture is the only case to date in which the PTAB has granted a patent owner’s motion to amend.3 But, a close read of International Flavors reveals that the PTAB’s decision more likely serves as an outlier based on the facts of International Flavors rather than a general guide for patent owners attempting to amend their claims. Below, we discuss the PTAB’s standard for amending challenged claims during an IPR trial, how the patent owner in International Flavors met that standard, and why the standard remains difficult to meet for most patent owners.
The Standard for Amending Claims in an IPR
The PTAB first outlined the standard for amending claims challenged during an IPR in a June 2013 decision in Idle Free Systems, Inc. v. Bergstrom, Inc.4 InIdle Free, the PTAB dismissed the patent owner’s initial motion to amend, explaining that a patent owner bears the burden “to show a patentable distinction of each proposed substitute claim over the prior art.”5 The PTAB later dismissed the patent owner’s renewed motion to amend because the patent owner again failed to show that its proposed substitute claims were patentable.6 The PTAB explained that a patent owner “bears the burden of proof in demonstrating patentability over the prior art in general,” not just the prior art of record.7 To do so, the patent owner is “expected to set forth ... the level of ordinary skill in the art, and what was previously known, regarding each feature it relies on for establishing patentability of its proposed substitute.”8
As explained in Idle Free, the PTAB places the burden of proof on the patent owner because substitute claims are not subjected to examination like new or amended claims during inter partes reexamination.9 “Rather, the proposed substitute claims will be added directly to the patent, without examination, if the patent owner’s motion to amend claims is granted.”10 Thus, “[a]s the moving party, a patent owner bears the burden to show entitlement” to the amended claims.11
In Avaya Inc. v. Network-1 Security Solutions, Inc., the PTAB presented a hypothetical to clarify the patent owner’s burden for amending a claim during an IPR: “[I]f a feature Z is proposed to be added to a claim to render it patentably distinct from the prior art, it would be essential for patent owner to establish the significance of feature Z from the perspective of the level of ordinary skill in the art. It is of little value only to state that no prior art teaches or suggests multiple claim elements including feature Z.”12 Instead, patent owner should first “indicate whether feature Z was known in any context, and if so, then explain why that context is so remote or different from that of the claimed invention that one with ordinary skill in the art would not have applied that teaching to arrive at the claimed invention.”13 Next, the patent owner should explain “why one with ordinary skill in the art would not have adapted relevant basic or general techniques taught in textbooks in the field of the invention to the particular use required by the claimed invention.”14
In addition to the high burden to demonstrate patentability over the prior art, the technical requirements for motions to amend add further hurdles for patent owners. For example, like all motions before the PTAB, motions to amend must be written in 14 point font, double spaced, and limited to 15 pages.15 The body of the motion must include a listing of each amended claim, potentially consuming valuable page space.16 Moreover, the patent owner must show “support in the original disclosure of the patent for each claim that is added or amended.”17 For example, if the amended claim language does not appear in the precise words of the original disclosure, “a mere citation to the original disclosure without any explanation as to why a person of ordinary skill in the art would have recognized that the inventor possessed the claimed subject matter as a whole may be  inadequate.”18 Thus, in some situations, the patent owner may need to “provide sufficient explanation in addition to citations to the specification.”19 The page limit and technical requirements, as well as the burden for demonstrating patentability over the prior art in general, have made it difficult for patent owner’s to file successful motions to amend.
Meeting the Standard: International Flavors
The PTAB’s recent decision in International Flavors represents the first time that the PTAB has granted an IPR motion to amend.20 International Flavorsinvolved U.S. Patent No. 7,579,016 (the ’016 Patent), which is directed to the use of isolongifolanone analogs to repel arthropods. Instead of filing a response to the IPR petition, the patent owner – the U.S. Government – filed an unopposed motion to amend, requesting cancellation of claims 1-26 and the addition of substitute claims 27-45.21
The PTAB held that the patent owner met the burden for demonstrating that substitute claims 27-44 were patentable over the prior art in general.22 In support of its motion to amend, the patent owner had submitted journal publications and an expert declaration to demonstrate the level of ordinary skill in the art and the non-obviousness of the substitute claims.23 According to the PTAB, the patent owner’s evidence “demonstrates that even small changes in structure can change the biological activity of an insect repellant.”24 Moreover, the PTAB found that the prior art “does not provide a reason to modify isolongifolanone to arrive at the modified isolongifolanone compounds of proposed claim 27, nor does it provide a reasonable expectation that such modifications would result in a compound having the desired insect repellant activity ... .”25
Analysis of International Flavors
The PTAB’s decision in International Flavors is undoubtedly important, as it shows that amending claims during an IPR is possible despite the legal and practical hurdles facing patent owners. However, further inspection ofInternational Flowers reveals that its usefulness as a guide for amending claims during an IPR may be limited to cases that involve chemical compounds and other unpredictable arts.
The new portion of independent substitute claim 27 in International Flavorsinvolved the further definition of a chemical formula.26 This fact is important because, in Takeda Chemical, the Federal Circuit held that the Teaching-Suggestion-Motivation (“TSM”) test can be used as a helpful guide when determining the obviousness of chemical compounds, despite the Supreme Court’s rejection of the rigid application of the TSM test.27 Relying on Takeda Chemical, the PTAB held that “in cases involving new chemical compounds, itremains necessary to identify some reason that would have led a chemist to modify a known compound in a particular manner to establish prima facie obviousness of a new claimed compound.”28 Because the prior art inInternational Flavors provided no clear reason to modify the prior art compounds, the PTAB concluded that substitute claim 27, and its dependents, were patentable.29 Given the PTAB’s reasoning, it is clear that the application of a stricter obviousness test in cases involving chemical compounds helped the patent owner to not only establish patentability over the prior art, but to do so within the strict 15 page limit.
The patent owner in International Flavors also benefited from several case-specific factors. For example, the chemical formulas involved in the new portion of substitute claim 27 were disclosed in exact terms in the original application.30 Accordingly, the patent owner’s mere citation to paragraphs of the original patent application established sufficient support without a page-consuming “explanation as to why a person of ordinary skill in the art would have recognized that the inventor possessed the claimed subject matter.”31Moreover, unlike petitioners in most IPRs, the petitioner in International Flavorsdid not oppose the patent owner’s motion to amend. Accordingly, the patent owner in International Flavors did not have to overcome any rebuttal evidence or arguments undermining the patentability of the substitute claims.
International Flavors provides an example of a successful amendment of claims in an IPR for patents directed to the unpredictable arts where even small changes in structure can have a large impact. However, patent owners in cases involving more predictable fields (e.g., the electrical or mechanical arts) face a more difficult task in establishing patentability over the prior art according to the requirements of Idle Free, especially given the technical requirements and the strict page limits for motions to amend. Accordingly,International Flavors will most likely serve as a singular example based on the particular facts of the case rather than as a general guide for meeting the burdens of proof for amending claims in an IPR as outlined in Idle Free.