Monday, June 6, 2022

Overbreadth Overlaps with Utility on the Facts

Janssen Inc v Sandoz Canada Inc 2022 FC 715 Pallotta J

2,659,770 / macitentan / OPSUMIT / NOC

In this NOC proceeding Sandoz conceded infringement and challenged the validity of the 770 patent on the basis of obviousness, lack of utility, overbreadth and insufficiency [8]. All attacks failed on the facts. One point of more general interest is that Palotta J followed and applied the recent decision in Abiraterone 2021 FCA 45 [41] (discussed here), in holding that a statistical analysis of the results, or statistical significance, is not required to establish a reliable basis for a sound prediction [234]. Also, the overbreadth attack once again failed to gain any independent traction, as it was held on the facts to be simply a rehash of the utility argument.

There are three known biological pathways affecting pulmonary blood pressure, namely the prostacyclin, nitric oxide and endothelin pathways [119]–[122]. PDE5 inhibitors work through the nitric oxide pathway [121]. Macitentan is an endothelin receptor antagonists (ERA), which, as the name suggests, works through the endothelin pathway [3]. The 770 patent relates generally to the use of combination therapy consisting of macitentan and a PDE5 inhibitor (such as sildenafil) to treat diseases involving vasoconstriction, particularly pulmonary hypertension [6], [113], [171]. So, claim 26 is to the use of macitentan in combination with sildenafil for the treatment of pulmonary hypertension [87].

Drugs operating through all three pathways were known and the main question in respect of obviousness was whether it would have been obvious to use, or at least try, a combination therapy. Pallotta J held on the facts that it was not obvious, as the evidence relating to the efficacy of combination therapies was limited and would not have provided an acceptable level of confidence that a combination therapy would work [159], [164], [185], [186]. The desirability of using a combination of an ERA and a PDE5 inhibitor, consequently was not obvious [188], and even if it was, the choice of macitentan in particular was not obvious [191], as it was “effectively unknown to the skilled person” at the relevant time [193]. Nor was the invention obvious to try; even if it was obvious to try a combination therapy (and Pallotta J did not hold that it was), it was not obvious to try macitentan in particular from amongst the known ERAs [199], [206].

The utility attack was to the effect that the data disclosed in the patent was not sufficient to establish a sound prediction of utility, and particularly that the rat studies disclosed in the patent were not probative of benefit in humans, primarily on the basis that the studies themselves were flawed, and partly on the basis that animal studies (especially when flawed) are not adequately probative of efficacy in humans [221]. Palotta J rejected these arguments on the facts [229]–[237]. The main point of general interest is that Palotta J noted that a statistical analysis of the results, or statistical significance, is not required to establish a reliable basis for a sound prediction [234], citing Abiraterone 2021 FCA 45 [41] (discussed here.)

While utility was soundly predicted, Palotta J held that utility had not been demonstrated, on the basis that the asserted claims relate to use of the combination for the treatment of diseases in humans, and the rat studies would not necessarily translate to the same effect in humans. However, she acknowledged that the line between sound prediction and demonstrated utility is vague, and she stated expressly that “I do not intend to suggest that there is a bright line that requires, in every case, testing in human patients in order to support demonstrated utility for a drug intended to treat a disease in humans” [246]. Her conclusion was only that the evidence in this case was not sufficient to demonstrate utility in humans [246].

In my article Overbreadth in Canadian Patent Law: Part I (2020) 33 IPJ 21, I argued that overbreadth is almost always overlaps with some other ground of invalidity. However, in Seedlings 2021 FCA 154 (blogged here) the FCA affirmed that “overbreadth remains a proper ground of invalidity” [50]. Consequently, we are now seeing overbreadth raised regularly as a ground of invalidity. But parties attacking the validity to of a patent have struggled to find an approach to overbreadth which gives it any independent force. That pattern continues in this case, in which Pallotta J held that all the overbreadth arguments were really a restatement of utility arguments, and she dismissed them for the same reason [250]–[253]. There was one overbreadth argument which she declined to consider because it had not been properly raised [252]; this also looks like a utility argument to me.

Pallotta J dismissed the insufficiency argument very briefly [254]–[260]. Sandoz’s argument is a bit difficult to understand from Pallotta J’s brief description. It strikes me as being another rehash of the utility argument.

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