Monday, October 22, 2012

What Is a “Formulation”?

Gilead Sciences Canada, Inc v Canada (Minister of Health) / COMPLERA 2012 FCA 254 Trudel JA: Sharlow, Mainville JJA, aff’g 2012 FC 2 Mosley J (blogged here)

A question left aside in last week’s week post on this decision was whether the patent in question claimed a medicinal ingredient, and so would be eligible for listing under NOC Reg s 4(2)(a), or a formulation, eligible under 4(2)(b).

The ‘475 patent at issue includes a claim to two medicinal ingredients, tenofovir and emtricitabine, in combination with a third medicinal ingredient from the class of non-nucleoside reverse transcriptase inhibitors [claim 34; FC 24]. A “claim for the formulation” is defined (emphasis added) under the NOC Regs s 2 as

"claim for the formulation" means a claim for a substance that is a mixture of medicinal and non-medicinal ingredients in a drug and that is administered to a patient in a particular dosage form;

As the FCA emphasized, this definition requires that a formulation contain non-medicinal ingredient [27]. The relevant claims do not. Consequently, the FCA held that the eligibility of this claim turned on para 4(2)(a), not (b)[32].

This is a straightforward conclusion on the text of the provision. Why then did the Minister argue, in a point accepted by Mosley J, that the listing should be considered under 4(2)(b) [FC 37]? I think the key to the argument is captured in a statement by Russel J in Bayer Inc v Canada (Minister of Health)2009 FC 1171 [80], aff’d 2010 FCA 161, quoted by Mosley J at [FC 41]:

The essence of a compound patent is the medicinal ingredient; the essence of a formulation patent is the mixture of ingredients.

In this case, the inventive concept was the discovery that tenofovir and emtricitabine are chemically stable when combined with a third anti-viral of the claimed class [FC 25]. The essence of the invention was the mixture of ingredients, not the discovery of any new medicine. Thus a purposive perspective suggests that the Minister and Mosley J were correct in their interpretation. But text, context and purpose must all be read together, and “[w]hen the words of a provision are precise and unequivocal, the ordinary meaning of the words play a dominant role in the interpretive process” Canada Trustco 2005 SCC 54 [10]. In this case, my view is that the text was sufficiently unequivocal that it should dominate, so that the FCA was correct in its interpretation. However, this case does illustrate a shortcoming in the drafting of 4(2)(b), in that the text is inconsistent with the apparent purpose. In this case no harm was done, as the FCA held that the claim was eligible under 4(2)(a). This implies that a mixture of medicinal ingredients is eligible under 4(2)(a) even when the mixture is desirable for reasons of formulation, and not because of a new medicinal effect. That conclusion is perhaps problematic from a purposive perspective, but it does solve the problem of this type of claim falling between the cracks of 4(2)(a) and (b).

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