Idenix Loses Patent on HCV Treatment that Supported $2.54 Billion Infringement Verdict

By Steve Brachmann
February 25, 2018

Idenix Loses Patent on HCV Treatment that Supported $2.54 Billion Infringement VerdictOn February 16th, the District of Delaware granted a motion for judgment as a matter of law filed by Foster City, CA-based pharmaceutical giant Gilead Sciences (NASDAQ:GILD) to invalidate a patent owned by Idenix, a subsidiary of Kenilworth, NJ-based pharma firm Merck & Co. (NYSE:MRK). In invalidating the Idenix patent, the Delaware district court effectively overturns what had been the largest award for royalty damages in a U.S. patent infringement case ever handed out. After a two-week trial in December 2016, the jury had awarded Index $2.64 billion in damages, which was based on finding Gilead infringed the Idenix patent – U.S. Patent No. 7,608,597 — by selling the hepatitis C virus (HCV) treatments Harvoni and Sovaldi.

The opinion penned by Delaware’s Chief Judge Leonard Stark dismissed a motion filed by Gilead to reduce the $2.54 billion damages award handed out by the jury, and also dismissed a motion on invalidity of Idenix’s patent for failure to meet written description requirements mandated by 35 U.S.C. § 112. Chief Judge Stark did, however, find that Idenix’s U.S. Patent No. 7608597, titled Methods and Compositions for Treating Hepatitis C Virus, was invalid under Section 112 for lack of enablement.

“[W]hile judgment as a matter of law is improper on damages and written description, the ‘597 patent is invalid for lack of enablement,” Stark wrote.

Gilead had argued that the ‘597 was invalid for written description because a list of substituents disclosed in the specification failed to describe the full scope of the claims. Idenix pointed to expert testimony which established that the specification included clear indications that the HCV polymerase should be targeted in identifying effective compounds, thus limiting the scope of the claims by the functional limitation and guidance in the patent with respect to the polymerase target. The court found that substantial evidence supported the jury’s implicit finding that there was no lack of written description in the ‘597 patent.

In finding in favor of Gilead’s motion for invalidity based on enablement, the court noted two limitations outlined in claim 1 of the ‘597 patent: a structural limitation regarding the chemical makeup of the claimed nucleoside; and a functional limitation regarding the effective amount of the nucleoside used to treat HCV. Further, the court noted that the use of the nucleoside to target the NS5B polymerase, which Idenix contended was key to a compound demonstrating effectiveness in treating HCV, was not an explicit claim limitation. “The patent claims are not limited to compounds that are effective in treating HCV due to their acting on the NS5B polymerase,” the court’s opinion reads.

“In the Court’s view, it is undisputed that the Structural Limitations of the claims are satisfied by billions of compounds,” Chief Judge Stark wrote, noting that the claims allow for an indeterminate number of combinations. Idenix contended that a person skilled in the art would not fill in each compound variable with any element meeting the literal terms of the structural limitations. For example, given that the patent is directed at compounds effective as medicines for human beings, a person of ordinary skill would not place radioactive plutonium in the compound as that could kill a person. However, the court found that this explanation, at best, only reduced the scope of the structural limitations to “many, many thousands,” requiring that a person skilled in the art would still require a great deal of time and effort to synthesize every compound that met the structural limitations of the claims, even when refined by the functional limitations.

An appeal seems virtually certain with so much at stake.

The Author

Steve Brachmann

Steve Brachmann is a writer located in Buffalo, New York. He has worked professionally as a freelancer for more than a decade. He has become a regular contributor to, writing about technology, innovation and is the primary author of the Companies We Follow series. His work has been published by The Buffalo News, The Hamburg Sun,,, Motley Fool and Steve also provides website copy and documents for various business clients.

Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author and should not be attributed to the author’s employer, clients or the sponsors of Read more.

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There are currently 4 Comments comments. Join the discussion.

  1. Paul Morgan February 26, 2018 12:44 pm

    A D.C. JMOL [or S.J.] decision of invalidity under Section 112 [other than for a means-function claim] for lack of enablement [actually for an overly-broad generic claim in this case] is relatively rare. We will presumably see a Fed. Cir. appeal decision in this case?
    Were there no infringed narrower claims in this patent? Might a narrowing reissue still provide some limited value?
    The $2.54 billion damages award handed out by the jury is not surprising in view of what is being charged for the important new hepatitis C treatments.

  2. Kinch March 1, 2018 2:14 am

    Morgan, none of the dependent claims limited the scope of the compounds used for treatment. Moreover, they didn’t reduce to practice a specific 2-fluoro analog (in Harvoni). One wonders why they didn’t attempt a derivation claim on Pharmasset’s patent? Or why they didn’t attempt a re-issue by adding a dependent claim with a 2-halo compound?

  3. Paul Morgan March 1, 2018 11:36 am

    Thanks Kinch. But since you mention “derivation,” and it is so widely misunderstood, I recommend this recent law firm article:

    Also not sure why your “reduce to practice” would fit into the 112 issue here of over-broad-generic-only claims, even for pre-AIA patents?

    P.S. Anther solution to problems like this can sometimes be to keep a continuation or divisional pending until a preferred species is determined and can be claimed then, IF there is spec support for it.
    I frequently wonder if a case like this might be another case of the trend for company “cost savings” or “cost control caps” on prep and prosecution, aka “penny wise and Billion dollar foolish”

  4. Kinch March 1, 2018 12:15 pm

    Thanks for link Morgan, very informative. Re the reduction to practice, J Stark made it a point right off the bat that the generic claim was allegedly not enabled because, at least, the application did not synthesize (or show exactly how to) the infringing compound.

    Also, I like you point about the CON, I see it all the time.

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