• Oct 30 2019
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  • Category: CAFC Updates

Idenix appeals from the decision of the District Court granting judgment as a matter of law (“JMOL”) against Idenix and finding that U.S. Patent No. 7,608,597 (relating to a method of treating hepatitis C virus (“HCV”) by administering nucleoside compounds having a specific chemical and stereochemical structure) is invalid for lack of enablement. Gilead argues that the patent is also invalid for failure to meet the written description requirement, and that the district court erred by failing to grant JMOL on that ground as well. With respect to enablement, the CAFC finds that a reasonable jury could only have found that at least many, many thousands of 2′-methyl-up nucleosides meet the structural limitations of claim 1, not all of which are effective to treat HCV. Due to the unpredictability of the art, each of these compounds would need to be screened in order to know whether or not they are effective against HCV. Moreover, a significant number of candidate 2′-methyl-up nucleosides would need to be synthesized before they could be screened, which increases at least the quantity of experimentation required, even if the synthesis was routine. Although the level of skill in the art is high, the ’597 patent does not provide enough meaningful guidance or working examples, across the full scope of the claim, to allow a POSA to determine which 2′-methyl-up nucleosides would or would not be effective against HCV without extensive screening. Given the immense breadth of screening required to determine which 2′-methyl-up nucleosides are effective against HCV, which can only be described as undue experimentation, the CAFC concludes as a matter of law that the ’597 patent is invalid for lack of enablement. With respect to written decision, the CAFC holds that the ’597 patent is invalid for lack of written description, as it fails to provide sufficient blaze marks to direct a POSA to the specific subset of 2′-methyl-up nucleosides that are effective in treating HCV. Thus, the CAFC affirms as to non-enablement and holds that the patent is also invalid for lack of written description. Judge Newman dissents, because it is incorrect to include in the claims the large number of unclaimed chemical variants in the specification that are not described, not synthesized, and not tested for antiviral activity, and then to invalidate the claims because these variants are not described and not enabled.

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