Canada: Federal Court Of Appeal "Skinny Label" Case Highlights The Potential Power Of The Patentee

In Apotex Inc. v. Janssen Inc., 2023 FCA 220, the Federal Court of Appeal upheld a finding that a generic drug manufacturer seeking approval for a monotherapy was, nonetheless, inducing infringement of a combination patent. The decision builds on existing "skinny label" case law and suggests that a combination patent can extend the patentee's monopoly where a claimed combination becomes the standard of care, even when a generic is not seeking that indication.

What the decision means for patent infringement by inducement

To prove inducement of infringement of a patent, the patentee must show that:

• the acts of infringement will be completed by the direct infringer (in this case, users such as physicians, other health care professionals or patients);
• the acts of infringement will be influenced by the alleged inducer (e.g., the generic drug manufacturer or its distributor); and
• the influence will be exercised knowingly by the inducer (i.e., the inducer must know that their influence is being exercised over the infringer's activities but not necessarily that those activities will amount to patent infringement).

The draft generic product monograph is typically the key document in the inducement analysis in pharma cases. Earlier this year, the Federal Court of Appeal confirmed that the second prong of the inducement test may be met where the generic manufacturer includes the patented use as a recommended use in its product monograph—even if the patented use is only one of multiple recommended uses¹.

According to Apotex Inc. v. Janssen Inc., 2023 FCA 220, a finding of inducement is possible even if the generic product monograph does not list the patented use as an indication. Courts will read the generic's product monograph through the eyes of a prescribing physician or pharmacist. Where the patented use has become the standard of care, simply excluding the use from the product monograph may be insufficient for a generic to escape a finding of infringement. Below we analyze the background to the Federal Court of Appeal's decision and highlight what industry players should watch for going forward.

Trial judge relied on standard of care to find inducement of infringement

In Apotex Inc. v. Janssen Inc., 2022 FC 996, affirmed 2023 FCA 220, Apotex sought to market a proposed generic version of Janssen's OPSUMIT® (macitentan), a drug used to treat pulmonary arterial hypertension (PAH). Janssen's patent claimed the use of macitentan in combination with a phosphodiesterase type-5 (PDE5) inhibitor to treat PAH.

The indication and clinical use sections of Apotex's product monograph did not mention the use of macitentan in combination with a PDE5 inhibitor. The indication was for the clinical use of macitentan alone—that is, as a monotherapy. However, the trial judge found that a majority of PAH patients who were prescribed OPSUMIT also received a PDE5 inhibitor in combination. This combination of use was prevalent and pervasive. The evidence further established that physicians would not perform a side-by-side comparison of the Janssen and Apotex product monographs to identify the differences between them. In any event, Apotex's product monograph also included data from a landmark clinical study that showed the combination of macitentan and a PDE5 inhibitor was safe and effective. The evidence also established that few physicians were permitted by provincial regulations to prescribe macitentan, and those who were would be aware of that study.

Read as a whole, the trial judge found that Apotex's product monograph did not suggest that physicians should depart from the well-established practice of using the combination (and instead prescribe a monotherapy). On these highly specific facts, the trial judge found that the marketing and sale by Apotex of its product would induce infringement of Janssen's patent².

Federal Court of Appeal upheld finding of inducement

The Federal Court of Appeal upheld the trial judge's finding of inducement of infringement. The Court rejected Apotex's submission that explicit instruction and intention in the product monograph were required to meet the second prong of the test. The Court held that, even without explicit reference to combination treatment as an indication, it was open to the trial judge to find that Apotex's product monograph would influence the use of macitentan in combination with a PDE5 inhibitor.

The Court also confirmed that a trial judge may draw inferences about the generic manufacturer's knowledge of its influence. Apotex was aware that it was seeking approval for a substitute of a product it knew was available to physicians already treating PAH with combination therapy. Based on this evidence, it was open to the trial judge to find that Apotex knew or should have known that its product monograph would influence physicians' prescribing decisions. That was sufficient to meet the third prong of the test for inducing infringement.

Repercussions for generic manufacturers

This case suggests that, in order to succeed in "skinny label" cases, a generic manufacturer may need to overcome established prescribing practices, which may be influenced not only by the patentee's label but its market tenure as well. Some might say this is an instance of a patent to a combination being applied broadly to other unpatented uses, but this is the nature of the law of inducing and procuring.

Footnotes

1. Janssen Inc. v. Apotex Inc., 2022 FC 996 at paras 147-203.

2. Teva Canada Limited v. Janssen Inc., 2023 FCA 68 at para 110.

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