Biosimilars, otherwise known as subsequent entry biologics or “SEBs” in Canada, are a rapidly emerging trend in healthcare. There is a common misconception that biosimilars are “generic” biologic medications. In reality, biosimilars and traditional generic pharmaceuticals are significantly different, principally due to the distinct nature and complexity of the molecular structure of biologics. Biosimilars present novel and intriguing legal issues that are quickly rising to the forefront of legal commentary.
The emergence of biosimilars has come with improvements in technology, economics, and the prominent role that biologics now play in the healthcare setting. The complex technology used in the production of biologics is becoming less costly and early patents on the technology are now expiring. Biologics have also been accepted as a crucial treatment option for many indications that should occupy a standard care role, but the cost is often prohibitive. Biosimilars provide a more cost-effective option for patients to access valuable biologic treatments. Of course, not all biologic treatments will necessarily become available as biosimilars. Various business factors must be considered by potential biosimilar manufacturers, including the market size, the relevant science and technology, and the high cost of development and production.
To receive market approval for a biosimilar in Canada, like any traditional generic, the sponsor for the biosimilar must address the patent rights applicable to the comparator biologic. For small molecules, this requirement has resulted in fiercely contested litigation over the right to market entry. Such litigation is already underway for biosimilars, with the first decision in a SEB case under the Patented Medicines (Notice of Compliance) Regulations (the “Regulations”) released on November 10, 2015 (see Amgen Canada v Apotex, 2015 FC 1261).
The market approval process in Canada is unique in that any determination in a proceeding under theRegulations is not dispositive, but merely a preliminary decision for market entry. The patent remains valid and may be asserted in subsequent proceedings under the Patent Act, despite that the biosimilar sponsor’s invalidity allegations were found justified for regulatory purposes.
The right of a biologic patentee to initiate subsequent proceedings for patent infringement is favorable to patentees, particularly in the case of biologics, given that a biologic and its biosimilar counterpart may often be administered with the same fixed dosage regimen. For example, Humira® (adalimumab) is dosed in multiples of 40 mg, depending on the indication. As a result, the product is conveniently manufactured in 40 mg pre-filled syringes. Under Canadian patent law, a fixed dosage product may be patentable and presents a valuable asset in the battle over market presence between biologics and biosimilars. However, the ability of biologic innovators to obtain and assert rights for this type of subject matter is narrowly construed.
In Canada, certain dosage regimens may be patentable, although a patentee must walk a fine line when drafting the claims to avoid methods of medical treatment. This prohibition has been maintained since the seminal decision of the Supreme Court of Canada in Tennessee Eastman v Canada (Commissioner of Patents),  SCR 111. While Tennessee Eastman was decided under the now repealed section 41 of thePatent Act, recent decisions have shed greater light on why this prohibition exists and when it will be imposed.
In Abbvie Biotechnology v Canada, 2014 FC 1251, the Court stated that claims to methods of medical treatment, in a strict sense, “fence in a range within which physicians must exercise their professional skill and judgement” and prevent the exercise of their trade (para. 89). This has prevented claims to dosage regimens in some instances when they can be construed to cover a method of medical treatment. For example, in Janssen v Mylan Pharmaceuticals, 2010 FC 1123, the claims were directed to the treatment of Alzheimer’s disease with a first dosage of about 8 mg per day for about 2 to 10 weeks followed by a final dosage of about 16 to 24 mg per day thereafter. The claims were found to be unpatentable on the basis that the dosage ranges provided a recommendation to physicians requiring ongoing individualized surveillance.
Inventors have sought to side-step this problem by claiming dosages in the form a fixed product. This has been described as a “vendible product”, and a line of case law has emerged upholding this type of claim. InAbbvie, the claims were to a bi-weekly dosage regimen of 40 mg of Humira structured in the form of a claim to the use of the specific product in treating a condition, and pre-filled syringes of the product. The claims were found to be patentable as they did not cover a physician’s skill or judgment. However, the Court cautioned against placing too great an emphasis on the “vendible product” and outlined that the driving factor in each case will be whether professional skill and judgment is expected or necessary to be exercised within the claim.
In Cobalt Pharmaceuticals v Bayer, 2015 FCA 116, Justice David Stratas called for a full consideration by the Court of Appeal or SCC of the policy and logic arguments against the current law in Canada that methods of medical treatment are not patentable. Justice Stratas acknowledged that the issue would have to be squarely raised on the facts, but this should nonetheless provide incentive for litigants who have had patent claims defeated by this doctrine to seek appeal to these higher Courts for further consideration.
With the increasing number of biosimilar manufacturers seeking approval in markets around the world, including Canada, and the importance of dosage regimens for the administration of these extremely valuable and life-saving medicines, the issue of the patentability of methods of medical treatment may again be before the SCC in the coming years.
A version of this article was published by LexisNexis in The Lawyers Weekly, 12 February 2016