The Federal Court has allowed an infringement action concerning a macitentan product under the Patented Medicines (Notice of Compliance) Regulations (the Regulations). The Court dismissed allegations that the asserted patent claims were invalid for obviousness, lack of utility, overbreadth, and insufficiency of disclosure.


Janssen Inc. (Janssen) markets OPSUMIT® in Canada for the treatment of pulmonary arterial hypertension (PAH). OPSUMIT® is a tablet containing macitentan. Sandoz Canada Inc. (Sandoz) sought approval for a generic macitentan product.

Janssen and Actelion Pharmaceuticals Ltd. (collectively, the Plaintiffs) brought an infringement action under subsection 6(1) of the Regulations, arguing that Sandoz’s product will infringe Actelion’s Canadian Patent No. 2,659,770 (770 Patent). The 770 Patent covers the use of macitentan, an endothelin receptor antagonist (ERA), in combination with a phosphodiesterase type-5 inhibitor (PDE5-I), to treat diseases where vasoconstriction is involved, including PAH. Sandoz did not dispute infringement, but argued that the 770 Patent was invalid for obviousness, lack of utility, overbreadth, and/or insufficiency.

Preliminary Issue – The Skilled Person

While the parties agreed on claims construction, they disagreed on the characteristics of the skilled person. The Plaintiffs argued that the skilled person only needed to be experienced in the treatment of pulmonary hypertension (PH) and PAH, not in the treatment of other diseases involving vasoconstriction. Sandoz disagreed on the basis that the 770 Patent is directed to treating other diseases involving vasoconstriction as well. The Court sided with Sandoz on this point, noting that while some of the claims were restricted to PAH, the attributes of the skilled person do not change on a claim-by-claim basis.

The 770 Patent is Valid

Obviousness. The Court held that the asserted claims of the 770 Patent were not obvious.

The parties and the Court agreed that the inventive concepts of the asserted claims were clear from the claims as construed, and that no recourse to the patent’s description was necessary to discern them. The Court highlighted that these inventive concepts did not include any alleged advantages to the combination of macitentan and PDE5-Is referred to in the description.

The Court rejected both of Sandoz’s main arguments as to why it would have been obvious for the skilled person to use macitentan as the ERA in combination with a PDE5-I to treat a disease involving vasoconstriction:

  • Sandoz argued that selecting macitentan was not inventive. This argument was based on Sandoz’s contention that it was known that combination therapy using any ERA and a PDE5-I would be effective in treating a disease involving vasoconstriction. The Court acknowledged that the studies on using such combination therapy showed some positive results, but found that it was not clear that the tested combination therapies were effective—let alone that these findings could be extrapolated to a combination of any ERA with a PDE5-I. The Court found that the skilled person would not have expected any ERA to work in combination with a PDE5-I, so it was not obvious to select macitentan from among them.
  • Sandoz argued that the combination of macitentan and a PDE5-I would have been obvious to try. The Court disagreed, finding that even if the skilled person were motivated to pursue ERA and PDE5-I combination therapy, there would have been no basis, apart from hindsight, to lead them to test the particular group of ERAs containing macitentan—or macitentan in particular.

Lack of utility. The Court held that the 770 Patent was not invalid for lack of utility.

The Court found that utility had not been demonstrated, as the claimed combination therapy had not yet been shown to be effective in treating humans with PAH. However, its utility had been soundly predicted.

The 770 Patent contains in vivo testing data from two different rat models for hypertension treated with macitentan and PDE5-I, both alone and in combination with each other. The Court found that these data, combined with the context and logical explanation for these effects in the common general knowledge, formed the factual basis for the prediction that combining macitentan with a PDE5-I would be effective at treating diseases involving vasoconstriction in humans. Given the known and observed vasodilatory effects of this therapy, there was a sound line of reasoning from this factual basis to this desired effect.

Overbreadth. The Court found that the 770 Patent was not invalid for claiming more than the invention made or disclosed.

In general, Sandoz’s overbreadth argument was based on allegations that certain claimed uses were not soundly predicted or had been shown not to work. The Court rejected these arguments for the same reasons as those on inutility. The Court also refused to consider one argument on the basis that it had not been pleaded and was raised for the first time in closing.

Insufficiency. The Court found that the 770 Patent was not invalid for insufficiency of disclosure.

Sandoz argued that the 770 Patent was missing information to enable the skilled person to treat certain diseases. However, Sandoz did not explain what necessary information was missing from the patent that is required in order to practice the invention. The Court found that the skilled person would have understood that the combination can be useful to treat these diseases by effecting vasodilation.

Link to decision: Janssen Inc. v Sandoz Canada Inc., 2022 FC 715