Friday, July 20, 2012

Product Specificity Requires Explicit Naming of Medicinal Ingredient

Novartis Pharmaceuticals Canada Inc v Canada (Attorney General) 2012 FC 836 Martineau J
Pat No. 2,304,819; Tobi Podhaler®

Martineau J’s decision refusing to allow Novartis’ ‘819 to list its patent against its Tobi Podhaler® product follows and applies the existing case law that interprets the principle of product specificity as requiring that a patent explicitly name the medicinal ingredient in the claims in order to be eligible for listing against a drug product. While this case illustrates once again some of the conceptual peculiarities of this approach to the product specificity requirement, it does not change the law in this respect. The decision does raises some interesting questions as to the boundary between a device such as a syringe which does not qualify as a dosage form at all, and once which might quality if it otherwise meets the product specificity requirements, which will be discussed in a subsequent post.

The Tobi Podhaler is a respiratory antibiotic, the sole medicinal ingredient of which is tobramycin, to be delivered via inhalation of a dry powder contained in a 28 mg capsule [4]. The ‘819 patent claims the use of a bioactive agent in an aerosolizing inhalation device comprising perforated microparticles. The patent also specifically claimed antibiotics as a type of bioactive agent, and it was conceded that tobramycin was antibiotic falling within the scope of the claims. However, tobramycin was not specifically named. Novartis sought to have the ‘819 patent listed on the basis of para 4(2)(b) (formulation) and 4(2)(c) (dosage form) of the NOC Regulations.

The Office of Patented Medicines and Liaison (OPML) refused to list the ‘819 patent against the Tobi Podhaler “on the sole basis that the approved formulation of Tobi Podhaler, containing tobramycin as its only medicinal ingredient, was not “contained” in any of the ‘819 patent claims within the meaning of paragraph 4(2)(b) of the Regulations because it was not explicitly named therein” [16]. Martineau J upheld this decision and this reasoning. He noted that the case law has established “a rather high threshold of specificity” [56] and indicated that is necessary to explicitly specify the particular medicinal ingredient [58]. Reference to a class of ingredients, not matter how narrow, does not suffice [60].

In my view Martineau J’s interpretation of the prior case law, in particular Purdue Pharma / TARGIN 2011 FCA 132 and Bayer / YAZ 2010 FCA 161, is straightforwardly correct. As I discussed in my post on Purdue Pharma / TARGIN, I’m not convinced that a requirement that the medicinal ingredient be specifically listed makes sense. It seems to me that product specificity is necessary to ensure that only patents which will almost certainly be infringed by a generic version of the reference products can be listed. The automatic statutory stay is a powerful tool, and in the absence of a review of likelihood of success on the merits, such as would be required to obtain an interlocutory injunction, listing eligibility is the main gatekeeper to ensure that the automatic stay is not triggered by a patent that has only a remote chance of being infringed. However, requiring explicit listing does not accomplish this goal, since a patent may be necessarily infringed by the reference product, as when the patent covers a genus encompassing a species that is not explicitly named. Also, it seems that when the specific medicinal ingredient is encompassed within the classed class, as in this case, the requirement can be satisfied simply by listing every possible antibiotic in the claims, in addition to referring to antibiotics generically. See for example claim 4 of patent 2468958, which is listed against Todi Podhaler. It is not clear what policy purpose is served by padding out patent claims in this manner. In any event, regardless of the logic, the point is now established, and Martineau J’s interpretation of the prior case law cannot be faulted. Also, I should add that I am not sure that '819 should be eligible for listing even on my argument as to the role of product specificity. While the product monograph for Tobi Podhaler specifies that “it is administered only by the oral inhalation route and only with the PODHALER* device,” it is not clear to me on the facts whether a generic version of the Tobi Podhaler would necessarily infringe the ‘819 patent.

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