Federal Circuit Revives Induced Infringement Claims

Federal Circuit Revives Induced Infringement Claims Despite "Skinny Label" Carve-Out

In Short

The Situation: The Hatch-Waxman Act allows generic drug manufacturers to "carve out" a brand's patented indications from their proposed labeling. Generic manufacturers often rely on these so-called "skinny labels" to try to avoid findings of infringement in standard Hatch-Waxman cases, but in post-marketing situations, the generic's "skinny label," coupled with its public statements, can be evidence of induced infringement even as to the carved-out, patented uses.

The Result: On June 25, 2024, the Federal Circuit, relying on a combination of Hikma's "skinny label" plus its marketing materials, reversed the District of Delaware's decision granting generic drug manufacturer Hikma's motion to dismiss Amarin's claims for induced infringement.  

Looking Ahead: Innovators should pay close attention to statements made by generic manufacturers when marketing their drug products even under "skinny labels," particularly statements that suggest a broader use fully equivalent to the brand.


This case represents another development in the saga over "section viii carve-outs" or "skinny labels," where the filer of an Abbreviated New Drug Application ("ANDA") seeks FDA approval to market a generic version of a drug, but "carves out" from its labeling indication(s) for use claimed by the patentee.

Amarin's drug Vascepa®, is FDA-approved for two indications: (i) severe hypertriglyceridemia ("SH indication"), and (ii) cardiovascular risk reduction ("CV indication"). Hikma filed an ANDA seeking to market a generic version of Vascepa®, but omitted the CV indication from its proposed labeling. In the initial Hatch-Waxman Act litigation filed in the District of Nevada (the "Nevada Litigation"), the district court ruled after a bench trial that Amarin's patents covering the SH indication were infringed, but invalid as obvious. Hikma's ANDA received FDA approval, and it began marketing its generic version of Vascepa® using labeling that carved out the CV indication. 

In November 2020, Amarin again sued Hikma, but this time for induced infringement of Amarin's CV indication patents. Hikma filed a motion to dismiss, arguing that it had carved out the CV indication in compliance with the Hatch-Waxman Act. On January 4, 2022, the Delaware District Court granted Hikma's motion because "there [had] been no instruction as to [the CV indication]." Amarin appealed.

The Federal Circuit's Decision

On June 25, 2024, the Federal Circuit reversed the lower court's decision. The court began by looking to Hikma's labeling, which "undisputed[ly] … [did] not provide an implied or express instruction to prescribe the drug for the CV indication." Amarin, however, also alleged that (i) other sections of Hikma's labeling, including the clinical trials section, suggested uses that fell within the scope of the asserted claims; (ii) Hikma's labeling contained a warning regarding potential side effects for use by patients with cardiovascular disease; and (iii) while an earlier iteration of Hikma's labeling included a "CV limitation of use" provision, Hikma revised its labeling and removed that provision once the FDA approved Amarin's Vascepa® for the CV indication. Amarin alleged that, despite Hikma's decision to carve out the CV indication, its labeling "would be understood by physicians as … teaching that the product could be prescribed to treat cardiovascular risk." Notwithstanding these allegations, the Federal Circuit said it "may [have] agreed with the district court (and Hikma) that the label does not, as a matter of law, 'recommend[], encourage[e], or promot[e] an infringing use.'" However, that was not the end of the inquiry. 

In addition to the labeling, the court considered Hikma's public statements and marketing materials. First, it assessed Hikma's website, which promoted its products as "AB-rated (i.e., therapeutically equivalent for only the labeled indications) in the therapeutic category 'Hypertriglyceridemia,'" which the court found was a category broad enough to encompass both the SH and CV indications. 

Second, it looked to Hikma's various press releases, which, while not including the "AB-rated" language, referred to Hikma's drug as a "generic equivalent to Vascepa®," "generic Vascepa®," or "Hikma's generic version of Vascepa®." These press releases also described Vascepa® as indicated "in part" for the SH indication. When read in the context of surrounding statements like "Hikma's generic version of Vascepa®," the court said these descriptors could encourage a reader to use Hikma's product as it would Amarin's product, i.e., for both the SH and CV indications. 

And third, the court recognized that Hikma's press releases "touted sales figures for Vascepa® that Hikma knew were largely attributable to the off-label CV indication." Indeed, Amarin's complaint pointed to an exhibit that Hikma relied upon in the earlier Nevada Litigation which showed that Hikma was aware that "at least 75% of sales of Vascepa® were for the patented CV indication." 

"[These] allegations, taken together with those relating to Hikma's label, at least plausibly state[d] a claim for induced infringement." Thus, the Federal Circuit held that at the motion to dismiss stage, it was "at least plausible" that a physician could view Hikma's labeling, website, and press releases as encouraging induced infringement. 


This post-marketing case indicates that public statements by a generic can be relied upon to show induced infringement of method of treatment patents, even where the generic uses a "skinny label." 

Three Key Takeaways

  1. An induced infringement analysis is not limited solely to the indications and usage section of the labeling; other sections may suggest infringing uses even in the context of a "skinny label."
  2. Once the generic goes to market, the narrow focus required in Hatch-Waxman Act litigation is no longer an issue, and branded companies can rely on the generic's public statements and market conduct to demonstrate inducement.
  3. Innovators should pay close attention to statements made by generics that may implicitly suggest off-label (i.e., carved-out) uses. 
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