The Importance of Product Specificity in the Listing Patents

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[author: Martin P.J. Kratz]

The Patented Medicines (Notice of Compliance) Regulations (SOR/93-133) provides the framework for most of Canada's patent litigation. The Patent Act and the PM (NOC) Regulations seek to balance “effective patent enforcement” over new and innovative drugs with the “timely market entry” of lower priced generic versions once the patents have expired. The PM (NOC) Regulations provide innovators of pharmaceutical patents with an ability to list their patents on a Patent List. A generic drug maker who wishes to obtain consent from Health Canada to market a drug based on the same active ingredient (called a Notice of Compliance or NOC) must address the applicable patents on the Patent List. The generic drug maker may address such listed patents by accepting that its product will not receive an NOC until expiry of a listed patent, or may assert that its product would not infringe the claims of such listed patent or may challenge the validity of a listed patent.

The PM (NOC) Regulations further provide the innovator with an extraordinary remedy – if the generic makes assertions of non-infringement or invalidity, the application for judicial review of such assertions gives the innovator an automatic two-year stay of the decision of Health Canada to issue the NOC – without having to satisfy the normal requirements for injunctive relief otherwise provided by law. During that two-year period the parties litigate the issues raised by the generic's allegations.

One can see, therefore, that it is of extraordinary importance to determine whether or not a patent may be properly listed on the Patent List. There must be a rational connection between the patents so listed and the regulatory submissions of the innovator against which the patents are submitted. The PM (NOC) Regulations provide the rules for assessing what patents may be listed. Given that there is so much litigation under the PM (NOC) Regulations, it is important to have a clear understanding of the applicable rules.

The Federal Court of Appeal had a recent opportunity to consider and provide clarity to these rules in Gilead Sciences Canada Inc. v. Canada (Health) , 2012 FCA 254.

Gilead had sought to list Patent 2,512,475 ( ‘475 Patent) in respect of a New Drug Submission (NDS) (the process by which the innovator seeks to obtain an NOC for the applicable drug) seeking approval of a drug for the treatment of human immunodeficiency virus (HIV) infection. The NDS stated that the drug, known as Complera, contained the medicinal ingredients: tenofovir, emtricitabine, and rilpivirine. The '475 Patent claimed chemically stable characteristics of tenofovir and emtricitabine in combination and sometimes with a third medicinal ingredient. The '475 Patent did not claim rilpivirine.

The listing criteria require that to be eligible for listing the patent must contain, under section 4(2)(a), "a claim for the medicinal ingredient" or under section 4(2)(b) "a claim for the formulation that contains the medicinal ingredient", in either case where the medicinal agreement or formulation had been approved through the issuance of an NOC in respect of the Submission.

Gilead claimed listing of the '475 Patent under either section 4(2)(a) or 4(2)(b).

The Minister of Health refused to list the ‘475 Patent on the Patent Register as, in his view, it did not meet the requirements of section 4(2)(b) that require that, to be eligible for listing, the patent must contain "a claim for the formulation that contains the medicinal ingredient and the formulation has been approved through the issuance of a notice of compliance in respect of the Submission."

The Minister found that the medicinal ingredients claimed in the ‘475 Patent did not match up with those in the NDS. The Minister found that “a patent containing claims for a formulation cannot 'match' the approved formulation unless both formulations explicitly contain all of the same medicinal ingredients.” The Minister found that the '475 Patent did not meet the “matching requirement” for lack of product specificity. Gilead sought judicial review.

The test for judicial review of the Minister's decision required the Federal Court to assess: (1) the correct construction of the ‘475 Patent; (2) the proper interpretation of sections 4(2)(a) and (b) of the PM (NOC) Regulations; and, (3) whether the Minister’s decision to exclude the ‘475 Patent from the Register was reasonable.

The Federal Court accepted the Minister’s position and dismissed Gilead's application for judicial review. The Federal Court had found that the object of the invention was to take advantage of the chemically stable characteristics of tenofovir and emtricitabine in combination and sometimes with a third medicinal ingredient.

While there was no dispute with the construction of the claims, the Federal Court had jumped directly to describe these claims in comparison with the three ingredients contained in Complera, without interpreting both sections 4(2)(a) and (b) to assess whether the claims fell more appropriately under (a) or (b).

The FCA found that both the Minister and the Judge failed to give sufficient weight to the requirement that formulations, by definition, contain non-medicinal ingredients and set out a particular dosage form, which is administered to the patient. In the case of the '475 Patent it was clear that the relevant claims did not meet the definition of "formulation", because they did not contain non-medicinal ingredients. The FCA rejected the argument that claims to a combination of medicinal ingredients was a “formulation of the separate medicinal ingredients into the new combination product” as the definition of "formulation" in the PM (NOC) Regulations is clear and must contain both medicinal and non-medicinal ingredients.

Here, since the '475 Patent did not claim a formulation and only claimed medicinal ingredients, the '475 Patent should properly have been considered by the Minister or the Federal Court under section 4(2)(a) which deals with claims to medicinal ingredients.

Gilead argued for a low threshold of connection between the wording of the NDS and the patent claim and also that the PM (NOC) Regulations must be given a broad interpretation.

The FCA rejected these arguments noting that it had confirmed in Purdue Pharma v. Canada (Attorney General), 2011 FCA 132, dealing with another subsection of the PM (NOC) Regulations, that absent precise and specific matching between the patent claims and the approved NOC, the patent was not eligible for listing. The FCA noted that the wording of section 4 is consistent across the four subsections and requires a high degree of specificity between the wording of the claim and the NOC.

The FCA affirmed the Federal Court's reasoning on product specificity that “the claimed formulation and the approved formulation do not match precisely and the requirement of product specificity is not met” and then considered the '475 Patent under section 4(2)(a). In conclusion the FCA upheld the Judge’s conclusion that the patent claims fail the requirement for product specificity because they do not make specific reference to the medicinal ingredient rilpirivine, but only the broad class of compounds, but the FCA did so under section 4(2)(a) rather than 4(2)(b).

The Gilead decision reinforces the importance of strict compliance with the listing requirements under the PM (NOC) Regulations. This strict approach to addressing the listing requirements is consistent with the policy, set out in the RIAS underlying the 2006 amendments to the PM (NOC) Regulations, that where the patent fails to meet the listing requirements, policy considerations tip the balance in favour of the generic manufacturer, and the matter is better left to the alternative (and traditional) judicial recourse of an infringement action. It is worth remembering that the PM (NOC) Regulations are an exceptional process and provide unusual rights to the patent owner additional to the rights provided to all patent owners under patent law.

A version of this article will be published in SLAW.