HCV method of treatment claims invalid for lack of enablement and written description

Idenix Pharmaceuticals LLC et al. v. Gilead Sciences Inc.

Docket Nos. 2018-1691
October 30, 2019

Brief Summary: DC grant of JMOL to Gilead finding HCV treatment patent invalid for enabled affirmed; FC panel also finds lack of written description.

Summary: Idenix appealed DC grant of a judgment as a matter of law (JMOL) to Gilead that Idenix’s US 7,608,597 directed to a method for treating hepatitis C virus (HCV) infection using nucleoside compounds (“2’-methyl-up nucleosides”) is invalid for lack of enablement. Gilead appealed the DC’s decision that the ‘597 patent is not invalid for a lack of written description (WD). The FC panel opinion explains that Idenix argued “the key to its invention, and to treatment of HCV, is the use of 2’-methyl-up nucleosides” (“having a methyl substitution (‘CH3’) at the 2’ ‘up’ position of the molecule’s sugar ring”, an argument Gilead argued “is overly broad, as the ‘597 patent provides no guidance in determining which of the billions of potential 2’-methyl-up nucleosides are effective in treating HCV.” Gilead argued that the ‘597 patent “primarily describes” nucleosides having “a hydroxyl group (OH) at the 2’-down position” while its “accused product has fluorine (F), not OH” at that position, which the ‘597 patent does not disclose or enable. “At Idenix’s urging”, the FC panel explained, the DC “construed the preamble, ‘[a] method for the treatment of a [HCV] infection,’ as a narrowing functional limitation” and that combined “with the requirement to administer an ‘effective amount,’…limits the scope of the claims to the use of some set of compounds that are effective for treatment of HCV.” The FC panel wrote that “[c]laim 1, therefore, encompasses any -D nucleoside meeting both” the structural and functional limitations, of which “[i]t is undisputed…there are billions of potential 2’-methyl up nucleosides”, and that “[t]he key enablement question is whether a person of ordinary skill in the art would know, without undue experimentation, which…would be effective” (In re Wands, FC 1988; Wyeth, FC 2013 (millions of possible compounds “while only a ‘significantly smaller’ subset…would have the claimed ‘functional effects’”)). After considering the Wands factors, the FC panel “conclude[d] that they would not” (e.g., “quantity of experimentation…is very high” which “weighs in favor of non-enablement”, “[i]t is the specification, not the knowledge of one skilled in the art, that must supply the novel aspects of an invention” (Genentech, FC 1997), that synthesis of many nucleosides was necessary but routine weighs against non-enablement (Wyeth, FC 2013), working examples “exceedingly narrow relative to the claim scope” (Enzo Biochem., FC 2009; Enzo Life Sci., FC 2019) and unpredictable art (In re Fisher, CCPA 1970) favor non-enablement).

On WD, the FC panel explained that the parties focused “in particular on whether the specification demonstrates possession of the 2’-methyl-up 2’-fluoro-down nucleosides that are the basis of Gilead’s accused product”. It agreed with Idenix “that generally a genus can be sufficient” if “a representative number of species” or “structural features common to the members of the genus” are disclosed (Ariad, FC 2010 (“nucleotide-by-nucleotide recitation of the entire genus” not required); Carnegie, FC 2008; Fujikawa, FC 1996; Bos. Sci., FC 2011), but concluded the ‘597 patent was invalid for lack of WD (“fails to provide sufficient blaze marks” (Fujikawa); discloses “not method of distinguishing effective from ineffective compounds reaching beyond the formulas disclosed”). The FC panel therefore reversed the DC’s finding of no invalidity for lack of WD.

Judge Newman’s dissent argued the decision holds “that validity under section 112 is determined based on whether unclaimed subject matter is described and enabled, provides a new path of uncertainty and unreliability of the patent grant” (FN3 noted that the dissent reached this conclusion “only by disregarding” the DC’s “binding claim construction”).

This entry was posted in Claim Construction, Enablement, Uncategorized, Written description. Bookmark the permalink.

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