Has the Federal Circuit Made It Nearly Impossible to Maintain Genus Claims?January 26, 2021

A recent denial by the Supreme Court of the United States (SCOTUS) to hear an appeal by Merck’s Idenix Pharmaceuticals LLC (Idenix), leaves unanswered questions regarding the overall validity of genus claims, particularly within the biopharma field. The SCOTUS denied a petition for writ of certiorari to clarify certain Section 112 requirements with respect to genus claims, leaving in place the Federal Circuit’s invalidation of Idenix’s patent for lack of enablement and written description.

This particular case involved a new generation of drugs for the treatment of hepatitis C, where Idenix accused Gilead Sciences, Inc. (Gilead) of infringing its patent on a family of compounds having the same basic chemical structure. At the district court level, a jury found Gilead infringed the Idenix patent with its drugs Sovaldi® and Harvoni®, and awarded Idenix $2.54 billion. However, the district court judge overturned the jury verdict by granting a motion for judgment as a matter of law (JMOL) for patent invalidity due to lack of enablement. Not only did the Federal Circuit uphold the district court’s non-enablement judgment, but they further found the patent was invalid for lack of written description.

The claims recited a family of compounds under the structural limitation of “β-D-2′-methyl-ribofuranosyl nucleoside” where the courts construed the compound to require a methyl group in the 2’ up position and nearly any non-hydrogen substituent at the 2’ down and 3’ down positions. With respect to enablement, the Federal Circuit found that the structural genus of the claim encompassed at least “many, many thousands” of candidate compounds, and therefore, the quantity of experimentation to determine which 2’-methyl-up nucleosides would have efficacy against hepatitis C would be “very high.” Furthermore, the Federal Circuit concluded that the art was unpredictable and Idenix failed to provide any meaningful guidance as to which 2’-methyl-up nucleosides were effective against hepatitis C.

In invalidating the Idenix patent for lack of written description, the Federal Circuit indicated that the patent fails to disclose either “a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can visualize or recognize the members of the genus.” While the patent included eighteen “principal embodiments,” the court concluded that there was no indication as to which nucleosides outside of those disclosed in the principal embodiments could be effective to treat HCV, and further did not provide any meaningful guidance as to what makes the identified nucleosides to be effective.

This Federal Circuit ruling has gained a lot of attention due to the overarching impact it could have on applicants in the chemical, pharmaceutical and biotech industries. Amgen, GlaxoSmithKline (GSK) and a group of intellectual property professors filed a trio of amicus briefs placing their support behind Idenix, warning that the future of innovation was on the line. GSK argued that years of research and billions of dollars are invested into finding those “critical” genus claims. Without being able to patent those findings, companies could be discouraged from engaging in such research, ultimately stifling innovation.

On the other hand, Gilead argues that this is simply a case of a bad patent with “sweeping broad claims” given that it claims “billions of untested and largely unmade candidate compounds” without describing or teaching how to make or use them. Perhaps the courts agree with this limited application of the Federal Circuit ruling, however, it begs the question, “when is a genus claim too broad?”

Until further clarification is provided by the courts, it is important that applicants seek advice and counsel of an attorney with experience and knowledge in this area to ensure that sufficient disclosures are being made within the patent application.

The Federal Circuit Opinion may be found here.

Tina G. Yin-Sowatzke, Pharm.D. is an Associate Attorney in the MVS Biotechnology & Chemical Practice Group. To learn more, visit our MVS website, or contact Tina directly via email.

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