Sanofi Sues Genentech, Says Suit Threat Hurts Praluent Sales

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By John Aquino

July 28 — Sanofi-Aventis U.S. LLC and Regeneron Pharmaceuticals sued Genentech Inc. July 27 in federal district court, seeking a declaration that their cholesterol-lowering drug Praluent, which the FDA approved July 24, doesn’t infringe Genentech’s patent and that the patent is invalid.

Praluent (alirocumab) is anticipated to become a blockbuster drug because one out of every three Americans has high levels of low-density lipoprotein (LDL) cholesterol, also known as “bad” cholesterol, which doubles their risk for heart disease, according to the Centers for Disease Control and Prevention.

Sanofi and Regeneron told the U.S. District Court for the Central District of California that Genentech has asserted that its “Cabilly” family of patents broadly covers “the use of certain well-known, conventional methods to produce any antibody product in any type of host.” Genentech has actively enforced the Cabilly patents, named after one of the patent’s inventors, against other makers of recombinant monoclonal antibodies like Praluent, Sanofi and Regeneron alleged.

The plaintiffs wrote that they brought the lawsuit “to lift the cloud created by the imminent threat of a lawsuit” by Genentech against Sanofi that “impedes the manufacture, marketing and sale of Praluent.”

Praluent, which is injected under the skin once every two weeks, is priced at $14,600 for a year’s treatment, and its high cost has already generated concern among health-care payers, although that price doesn't include industry discounts and rebates.

Prior Genentech Litigation 

Genentech's U.S. Patent No. 7,923,221 is titled “Methods of Making Antibody Heavy and Light Chains Having Specificity for a Desired Antigen” and is referred to as the “Cabilly III patent.”

The Food and Drug Administration approved Praluent for treating adults with heterozygous familial hypercholesterolemia or clinical atherosclerotic cardiovascular disease who require additional lowering of LDL-cholesterol.

Sanofi and Regeneron asserted in the complaint that Praluent is the first monoclonal antibody approved in the U.S. that targets PCSK9 (proprotein convertase subtilisin/kexin type 9), an enzyme encoded by the PCSK9 gene that acts in cholesterol homeostasis (the regulation of a system so that internal conditions remain stable and relatively constant).

The plaintiffs noted in their complaint that Genentech has asserted infringement of the Cabilly patents in litigation against other manufacturers of recombinant monoclonal antibodies, including GlaxoSmithKline. In these litigations, Genentech has alleged that the process and certain starting materials used to produce the antibodies infringe one or more claims of the Cabilly III patent, Sanofi said.

According to the complaint, the '221 patent is invalid because it is anticipated by prior inventions or publications under 35 U.S.C. §102, is obvious under 35 U.S.C. §103, or both. Sanofi and Regeneron also asserted that the '221 patent is invalid under the judicially created doctrine of obviousness-type double patenting.

Judgments, Injunctive Relief 

The plaintiffs also asked the court for a declaratory judgment that making, using, importing and selling Praluent doesn't and won't infringe any valid and enforceable claim of the Cabilly III patent. They asked the court to order Genentech to stop enforcing the '221 patent and to pay the plaintiffs' costs and attorneys' fees for the litigation.

A Genentech spokeswoman told Bloomberg BNA in a July 28 phone call that the company doesn’t comment on pending litigation.

The complaint was filed by Elizabeth Mann of Mayer Brown LLP, Los Angeles, with Lisa M. Ferri, Brian W. Nolan and Richard J. McCormick of Mayer Brown, New York, of counsel.

To contact the reporter on this story: John T. Aquino in Washington at

To contact the editor responsible for this story: Lee Barnes at

The complaint is at