The answer? Not much, in itself. If one patent is good, 132 is probably fine too. That was Judge Easterbrook’s reasoning in a recent decision addressing indirect purchasers’ antitrust challenge to AbbVie’s so-called “patent thicket” of 132 patents around the blockbuster drug Humira, arguing the sheer number of patents blocked

In one of the first district court opinions applying the Federal Circuit’s recent GSK decision on induced infringement in the context of label carve-outs (the “GSK decision,” discussed here and here), Judge Richard Andrews in the District of Delaware held that plaintiff Amarin Pharma (“Amarin”) failed to plead facts sufficient to show that Hikma Pharmaceuticals’ (“Hikma”) carved-out product label and/or public marketing statements induced infringement of Amarin’s patents. The holding suggests that carved-out labels (so-called “skinny labels), despite the GSK decision, continue to provide some measure of protection from liability based on induced infringement.

On August 5, 2021, the Federal Circuit withdrew its October 2020 opinion in GSK v. Teva, summarized in this post on induced infringement of method-of-treatment claims, and issued an opinion that reiterated the prior holding but sought to clarify its reasoning. GlaxoSmithKline v. Teva. Specifically, the majority stated that a generic manufacturer’s touting of AB equivalence to a brand drug is generally not evidence of intent to induce infringement—but in the specific facts of this case it did support inducement, because the Court found ample evidence tying claim limitations to statements in Teva’s label even though the patented method was omitted as a distinct indication. The Court also found that Teva’s advertising statements regarding treating “heart failure” evidenced intent to induce physicians to prescribe the drug to treat CHF.

Reference product sponsors often obtain patents claiming methods of using a known drug to treat a condition or disease. Because generic and biosimilar developers typically do not treat patients, and thus do not directly infringe the claims, plaintiffs must sue under a theory of induced infringement—i.e., that the generic or biosimilar developer recommended, encouraged, or promoted a patented use for the drug. Demonstrating induced infringement most often involves the label of the defendant’s product, but increasingly may involve non-label evidence such as the defendant’s press releases, brochures, product catalogs, advertisements, and statements to the FDA, doctors, and investors. This non-label evidence is likely to be especially significant in the biologic context.