889 F.3d 1372
Fed. Cir.2018Background
- Patent-in-suit: U.S. Patent No. 7,582,621 (the ’621 patent) claims use of tavaborole (a benzoxaborole) to treat onychomycosis, specifically tinea unguium (dermatophyte-caused nail infection).
- Petitioner (Coalition for Affordable Drugs X) filed IPR challenging all claims as obvious based on Austin (oxaboroles including tavaborole; activity vs. Candida albicans) combined with Brehove (dioxaborinanes; topical treatment of onychomycosis; in vivo success in five patients).
- Key technical disputes: whether a skilled artisan would combine Austin and Brehove, whether tavaborole would be expected to penetrate the nail, and whether activity vs. C. albicans predicts activity vs. dermatophytes.
- Record evidence included expert declarations/depositions and literature: Segal, Mertin (three-part study), Nimura, petitioner’s experts (Murthy, Kahl), and patent-owner experts (Lane, Ghannoum).
- The PTAB found motivation to combine and a reasonable expectation of success (functional similarity re: activity against C. albicans; tavaborole’s low molecular weight aiding nail penetration) and held claim 6 (tinea unguium) obvious. Anacor appealed only claim 6; the Federal Circuit affirmed.
Issues
| Issue | Anacor's Argument | Coalition's Argument | Held |
|---|---|---|---|
| Whether PTAB violated APA/due process by adopting a new theory or relying on new references (Segal, Mertin) | Board adopted a novel theory and relied on new evidence in petitioner’s reply without proper notice | Theory and evidence were within scope of petition/reply and were raised earlier by both sides (depositions, responses, hearing) | No APA/due process violation; Anacor had notice and opportunity to respond |
| Whether PTAB shifted burden to patent owner to disprove obviousness | Board effectively required Anacor to disprove obviousness and failed to require petitioner proof of mechanism or specific evidence tavaborole would act on dermatophytes | Petitioner met its burden via combination of Austin and Brehove plus supporting literature and expert testimony showing expectation of cross-species antifungal activity | No burden shift; PTAB repeatedly stated petitioner’s burden and substantial evidence supports obviousness finding |
| Whether structural dissimilarity precludes motivation/reasonable expectation of success | Structural differences between benzoxaboroles and dioxaborinanes mean properties could differ substantially; structural similarity insufficient | Functional evidence (both groups active vs. C. albicans), plus some structural similarity and tavaborole’s favorable MW/permeability, support combining and expectation of success | Structural similarity was not treated as dispositive; combination of functional and structural evidence yields substantial support for PTAB’s conclusion |
| Whether substantial evidence supports obviousness of claim 6 (tinea unguium) | No reliable basis to infer tavaborole would treat dermatophytes from activity vs. C. albicans; unpredictability and lack of direct data defeats reasonable expectation | Austin’s data (tavaborole potent vs. C. albicans), Brehove’s in vivo onychomycosis results, literature showing dermatophytes often more sensitive, and expert testimony support reasonable expectation | Substantial evidence supports PTAB: motivation to combine and reasonable expectation tavaborole would treat dermatophyte onychomycosis; claim 6 invalid for obviousness |
Key Cases Cited
- Dell Inc. v. Acceleron, LLC, 818 F.3d 1293 (Fed. Cir.) (IPR patent-owner notice and opportunity standards under APA)
- Genzyme Therapeutic Prod. Ltd. P’ship v. Biomarin Pharm. Inc., 825 F.3d 1360 (Fed. Cir.) (agency may not change theories midstream; new evidence in reply can be permissible)
- In re NuVasive, Inc., 841 F.3d 966 (Fed. Cir.) (limitations on board adopting new theories not presented in petition)
- Novartis AG v. Torrent Pharm. Ltd., 853 F.3d 1316 (Fed. Cir.) (no APA violation where patent owner had notice of reference through filings and hearings)
- In re Magnum Oil Tools Int’l, Ltd., 829 F.3d 1364 (Fed. Cir.) (analysis of burden shifting in IPR context)
- Daiichi Sankyo Co. v. Matrix Labs., Ltd., 619 F.3d 1346 (Fed. Cir.) (role of structural similarity in obviousness of chemical compounds)
- Altana Pharma AG v. Teva Pharm. USA, Inc., 566 F.3d 999 (Fed. Cir.) (structural similarity can support inference of similar properties)
- Eisai Co. v. Dr. Reddy’s Labs., Ltd., 533 F.3d 1353 (Fed. Cir.) (chemical unpredictability; need for nexus between structural and functional similarity)
- In re Merck & Co., 800 F.2d 1091 (Fed. Cir.) (treatment patents using known compounds: similar compounds with common properties may suggest other shared properties)
- Fromson v. Advance Offset Plate, Inc., 720 F.2d 1565 (Fed. Cir.) (inventor need not understand mechanism of action for efficacy)