914 F.3d 1366
Fed. Cir.2019Background
- RCT owns reissue U.S. Patent No. RE38,551 claiming R-enantiomer lacosamide and related anticonvulsant compositions and uses; claims 8–13 (including lacosamide and high-purity/enantiomer/composition/use claims) remained at issue.
- Argentum petitioned for inter partes review (IPR) challenging claims 1–13; the Board instituted on two grounds combining Kohn (1991) and Silverman, and (for dependent claims) Kohn, Silverman, and the ’729 patent.
- Petitioners (Argentum, later joined by Mylan, Breckenridge, and Alembic) advanced a lead-compound theory selecting Kohn compound 3l and argued bioisosteric substitution (replace an N-containing methoxyamino moiety with methylene) would have motivated a skilled artisan to arrive at racemic or R-lacosamide.
- The Board assumed compound 3l could be a lead but found substantial evidence showed a skilled artisan would not have been motivated to replace the methoxyamino group because prior art indicated loss of potency and significant conformational change, and Petitioners failed to show expected reduction in toxicity or clear synthetic/stability justification.
- The Board also declined to institute or rely on certain incorporated grounds (Ground 1B/LeGall) and concluded dependent claims 10–13 were not shown obvious in view of the failure on the independent claim.
- On appeal, the Federal Circuit (affirming) addressed standing of joined petitioners, reviewed factual findings for substantial evidence, and declined to remand under SAS due to waiver.
Issues
| Issue | Appellants' Argument | RCT's Argument | Held |
|---|---|---|---|
| Article III / §319 standing to appeal by joined petitioners | Joined petitioners who were added under §315(c) have statutory right to appeal under §319 | Appellants lack zone-of-interests under §319 because their petitions were time-barred and Argentum (initial petitioner) lacked standing | Joined petitioners fall within §319 zone of interests and may appeal; standing affirmed |
| Obviousness of claims 1–9 (lead-compound modification from Kohn 3l) | A skilled artisan would have been motivated by bioisosterism (Silverman) and stability/synthetic concerns to replace the methoxyamino N with CH2 to make lacosamide; reasonable expectation of success | Kohn teaches methoxyamino confers potency and stability; record lacks specific evidence N–O bond lability or that methylene would preserve potency; conformational change counsels against modification | Substantial evidence supports Board’s finding that Petitioners failed to show motivation to modify 3l or a reasonable expectation of success; claims 1–9 not proven obvious |
| Obviousness of dependent claims 10–13 | (Relies on same grounds plus ’729 patent teaching racemic lacosamide usefulness) | Because independent claim not obvious and some referenced grounds were not instituted, dependent claims are not obvious | Court affirmed Board’s refusal to find dependent claims obvious because challenge to parent claim failed and certain grounds were not properly relied upon |
| Request to remand post‑SAS Institute v. Iancu | Remand to reconsider non‑instituted grounds per SAS | Opposes remand; argues waiver as request made late | Request denied as waived (petitioners raised SAS too late after decision) |
Key Cases Cited
- Lexmark Int’l, Inc. v. Static Control Components, Inc., 572 U.S. 118 (statutory zone‑of‑interests limit for private causes of action)
- In re Elsner, 381 F.3d 1125 (Fed. Cir. 2004) (standard of review for Board legal determinations)
- In re Gartside, 203 F.3d 1305 (Fed. Cir. 2000) (substantial‑evidence review of Board fact findings)
- Consol. Edison Co. v. NLRB, 305 U.S. 197 (substantial evidence explained)
- Yorkey v. Diab, 601 F.3d 1279 (Fed. Cir. 2010) (credibility determinations for expert testimony)
- W.L. Gore & Assocs., Inc. v. Garlock, Inc., 721 F.2d 1540 (Fed. Cir. 1983) (dependent claims not obvious when parent claim not obvious)
- In re Baxter Int’l, Inc., 678 F.3d 1357 (Fed. Cir. 2012) (obviousness is legal conclusion based on factual findings)
- SAS Institute Inc. v. Iancu, 138 S. Ct. 1348 (Sup. Ct. 2018) (complete‑review rule for instituted IPR grounds)