New examination guidelines

On March 18, 2015 the Canadian Intellectual Property Office (“CIPO”) issued a Patent Notice: Revised Examination Practice Respecting Medical Uses (the “Notice”), ostensibly to reflect the Federal Court decision in AbbVie Biotechnology Ltd v Canada (AG), 2014 FC 1251 (“AbbVie”). Practice notices do not have the force of law but are generally closely adhered to by Canadian patent examiners in reviewing patent applications.

The patentability of methods of medical treatment in Canada

Generally speaking, Canadian case law holds that medical methods are not patentable although new medical uses (of new or known products) may be patentable. A claim will be considered a method of medical treatment and be unpatentable subject matter if it interferes with a physician’s skill and judgment.

AbbVie Biotechnology Ltd v Canada (AG)

AbbVie appealed a decision of the Commissioner of Patents refusing its patent on the basis of the claims being directed to methods of medical treatment.  The patent application pertained to a fixed dosing regimen for AbbVie’s drug HUMIRA®. The Court considered a subset of the claims advanced before the Patent Appeal Board, which included syringe, Swiss-type use and use claims. The construction of the claims was not in dispute, and Justice Kane of the Federal Court characterized the essential elements of the claims as being a preloaded syringe of 40 mg of the drug HUMIRA® for the treatment of arthritic disease or an inflammatory bowel disease; administered subcutaneously; for use on an every other week dosing interval of 14 days (i.e., bi-weekly). The claims therefore included a fixed dose and dosing interval.

The Court reviewed the Commissioner’s decision under a standard of correctness. The Commissioner argued that prior case law,1 which it believed was reflected in CIPO’s earlier practice notice PN 2013-04, prohibited patenting of “how and when” a drug is administered. The Commissioner further argued that although the claims at issue recited a fixed dose and fixed schedule, the physician’s skill and judgment was still required to adhere to that dosing regimen at the outset.

Justice Kane rejected the Commissioner’s broad interpretation, noting that under the Commissioner’s approach, claims which had been found permissible in other cases should have been impermissible for including a dosage and dosing interval:

The respondent’s [Commissioner’s] approach appears to overlook that the professional- in this case the physician- must still exercise their skill and judgment to decide whether or not the claimed invention should be used as claimed (i.e., whether it is appropriate for a particular patient). Once that is determined, there may be no further need to exercise skill and judgment to vary the claimed way to use the invention. It is not expected and it is not necessary. The expert evidence about the invention will inform whether skill and judgment is expected or necessary to be exercised.[emphasis added]

Justice Kane held that the claims at issue pertained to a fixed dose and a fixed interval, which obviated a physician’s skill and judgment in prescribing a dosing regimen. Thus, Justice Kane held that AbbVie’s patent claims were not methods of medical treatment and directed the Commissioner of Patents to allow the  patent application to issue.

Revised examination practice respecting medical uses

The Notice released in response to AbbVie supersedes the previous examination guidelines published by CIPO in June 2013. The previous guidelines focussed on an analysis of claim language and an identification of whether the essential elements of the claim reflected “how” to treat a patient (not allowable) versus one directed to “what” is used to treat a patient (allowable).

Under the new Notice, CIPO endorses an approach that considers the specification as a whole in answering this “how” or “what” question:

To perform a purposive construction, an examiner identifies the problem the inventors set out to address and the solution disclosed. This exercise generally must be performed considering the specification as a whole, recognizing that the description guides the identification of the problem and solution.

This is problematic for prosecution internationally because for most jurisdictions broad support for various embodiments (e.g. ranges and alternatives) is desirable. The Notice acknowledges that “an applicant is entitled to claim less that the entire invention if so desired”, but asserts that “a proper identification of the actual invention, grounded in a purposive construction of the claims, is nevertheless necessary in order to assess whether the claim is patentable.”

If the examiner determines that the essential elements are directed to “how” to treat a patient then the examiner is to determine “whether the essential element prevents, interferes with or requires the professional skill of a physician”. It is not clear whether CIPO will permit evidence to be adduced on this point or whether the analysis will continue to rely on the interpretation of the specification. In a positive development, theNotice does acknowledge that “essential elements that narrow treatment to a fixed dosage, a fixed dosage regimen, a patient subpopulation or to a particular administration site are not considered to point to a limitation of a physician’s professional skill or judgment.”

This approach of characterizing the claims based on a problem-solution review of the specification is not the approach taken in AbbVie (the analysis having been based on an agreed construction.) Time will tell ifAbbVie and the Notice open the door more broadly for patenting dosage form and regimen claims in Canada. It may be that in turning to the specification, CIPO is looking for a substitute to the expert evidence relied upon in the case law to determine whether the invention in fact restricts the skill and judgment of a physician. It is also possible that the Notice will maintain the status quo of severely restricting protection for dosage forms and regimens despite a decision holding that the standard espoused by CIPO to-date has been unduly restrictive.