The Canadian Patent Office recently released a new guidance
document on "Examination Practice Respecting Medical
Uses". The guidance document, PN 2013-04, is directed to
examiners, and relates to the consideration of claims directed to
methods of medical use and, in particular, the patentability of
claims containing a dosage regimen or dosage range.
While guidance documents are not binding on the courts, they may
be used as evidence in proceedings. They are also highly indicative
of the positions that patent applicants can expect from the
Canadian Patent Office.
The new guidance document reflects decisions of the courts on
medical use claims, and purports to build on the more general
guidance in section 17.02.03 of the Manual of Patent Office
Practice and also an earlier guidance document (PN 2013-02).
PN 2013-04 reiterates that:
methods of medical treatment are not patentable subject matter;
medical use claims will generally be permitted as long as they
do not equate to medical or surgical methods.
To determine whether medical use claims are patentable, the
essential elements of each of the claims must first be identified
based on a purposive construction of the patent. Thus, to determine
which elements of the claim are "essential", the
examiners are instructed to look at the whole of a patent's
specification to identify both the problem the inventors set out to
address and the solution disclosed.
Once the essential elements of the claims have been identified,
the examiners must determine whether the subject matter of the
claims is patentable in Canada. To constitute "patentable
subject matter", a claimed invention must fall within the
categories of "invention" specified in section 2 of the
Patent Act. Medical inventions such as methods of medical
treatment have been interpreted to fall outside the scope of
section 2. In contrast, medical use claims are generally
The guidance document provides some specific instructions to
examiners on how to determine whether medical inventions are
patentable.The question is whether the invention would prevent
physicians from exercising their skill and judgment in using a
known compound for an established purpose.
The primary rule of thumb is to consider whether the claim
answers the questions of "how?", or conversely,
"what?". Where an essential element only serves to
instruct a medical professional as to "how" or
"when" to treat a patient, the subject matter is most
likely an unpatentable method of medical treatment, since the
answer to such a question would likely place a limit on the
professional skill or judgment of a physician. Examples of
"how" include details of when or where a treatment is to
be administered, or who is to receive a treatment.
On the other hand, if the essential element instructs the
professional as to "what" to use to treat the patient,
this will not amount to a method of medical treatment.
The guidance document also focuses on an issue that has proven
to be particularly problematic in the assessment of patent claims:
dosage regimens or dosage ranges recited in the claims. A claim is
not unpatentable simply because it contains a dosage regimen or a
dosage range. Rather, the question for the examiner is whether an
essential element of the claim is a dosage regimen or a dosage
range encompassing the use of a known compound in an established
treatment. If it is, the claim covers a method of medical
treatment, and according to the guidance document, is
"non-compliant" with section 2 of the Patent
Notably, the guidance document does not discuss the decision in
the Finasteride case (Merck v. Pharmascience,
2010 FC 510), wherein Justice Hughes stated that there must be a
"claims that rely upon the skill and judgment of a medical
practitioner and those that deal with a vendible product, be it a
scalpel, X-ray machine or 1 mg tablet that are to be used or
prescribed for use by such practitioner. In the present case, we
have a 1.0 mg tablet taken as a daily dose. No skill or judgment is
brought to bear. It is a vendible product and not a method of
In view of that decision, it may be possible to argue that a
claim directed to a specific dose (as opposed to a range) and taken
at a specific time (every two days) is a vendible product and not a
method of medical treatment.
A recent Saskatchewan Court of Queen's Bench decision allowed a court-appointed receiver to sell and transfer intellectual property rights free and clear of encumbrances, finding that a license to use improvements of an invention was a contractual interest and not a property interest.
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