On May 14, 2018, the Federal Circuit affirmed the Patent Trial and Appeal Board's (the "Board") Final Written Decision in an inter partes review (IPR) proceeding holding all claims of Anacor Pharmaceuticals, Inc.'s ("Anacor") U.S. Patent No. 7,582,621 unpatentable for obviousness. The single claim addressed on appeal related to a method of using an oxaborole known as "tavaborole" to treat onchomycosis (a nail infection) caused by a dermatophyte. Dermatophytes are a type of fungus responsible for 90 percent of all cases of onchomycosis.
The IPR petition alleged that the claim would have been obvious in light of the combination of two references: Austin and Brehove. Austin teaches the use of oxaboroles as fungicides and discloses that tavaborole inhibits a variety of fungi, including C. albicans. Brehove teaches that use of similar types of compounds to treat onchomycosis and discloses the results of in vivo testing of two such compounds where a patient's onchomycosis was successfully treated. The Board concluded that a person of ordinary skill in the art would have expected that tavaborole, which shares functional activity with the Brehove compounds against C. albicans, would also have functional activity against other fungi responsible for onchomycosis (like dermatophytes), and would have combined Austin with Brehove with a reasonable expectation of success.
In reaching its conclusion, the Board cited evidence from three additional articles: Nimura, Segal and Mertin. On appeal, Anacor argued that the Board improperly relied on Segal and Mertin, which was new evidence not cited in the petition and to which Anacor did not have an opportunity to respond. The Federal Circuit explained that there is "no blanket prohibition against the introduction of new evidence," which is "to be expected" during an IPR proceeding, so long as the opposing party has notice and an opportunity to respond. Moreover, a petitioner may introduce new evidence in reply to the patent owner's evidence, or to document "the knowledge that skilled artisans would bring to bear" in the analysis.
Here, Anacor had notice and several opportunities to respond to both references. Anacor spent three pages of its patent owner's response discussing Segal. Mertin was the third article in a series of three. Anacor's expert, Dr. Lane, relied on the first two Mertin articles in her declaration. When cross-examined about the third Mertin article, Dr. Lane admitted that she was familiar with it. The third Mertin article was used again at the deposition of another Anacor expert and was discussed extensively by Anacor at the hearing before the Board. The Federal Circuit concluded that "Anacor had ample notice of and an opportunity to respond to the Segal and Mertin references, which in any event were properly offered in reply to arguments made by Anacor and for the purpose of showing the state of the art at the time of the patent application." Accordingly, Anacor had not been denied its procedural rights.
Anacor Pharms., Inc. v. Iancu, No. 17-1947 (Fed. Cir. May 14, 2018)
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