It is well known that methods of medical treatment do not
constitute patentable subject matter in Canada. One of the reasons
for this prohibition is to prevent a medical professional from
being barred from practicing a beneficial medical treatment that
may be based on their skill and judgment. Accordingly, claims
directed to surgical, medical, dental, or physiotherapeutic methods
of treatment are not patentable. In addition, there have been
several recent court decisions in Canada where dosage regimens were
held to be methods of medical treatment, and therefore not
patentable subject matter, and the corresponding patents held to be
invalid and unenforceable.
During prosecution of a patent application, objections to method
of medical treatment claims are generally overcome by simply
rewriting the claims in a manner that is acceptable to the Canadian
Patent Office. For example, a claim to a method of treating disease
X with compound Y would not constitute patentable subject matter,
yet by simply rewriting the claim as a use of compound Y to treat
disease X the subject matter-based objection will generally be
However, corresponding objections to claims where the point of
invention is how a medicine is to be used, such as a dosage
regimen, have now become more difficult to overcome and patents
containing such claims are being invalided by the courts.
For example, in two recent court decisions, Axcan Pharma
Inc. v. Pharmascience Inc. 2006 FC 527, and Janssen Inc.
v. Mylan Pharmaceuticals ULC. 2010, FC 1123), it was held that
the claims at issue contained a dosage range that required a
physician's skill and judgment to select the appropriate value
based on information from the patient. In Axcan, this
information was the patient's weight and in Janssen,
it was the patient's response to treatment. Also, in a recent
Patent Appeal Board decision (Commissioner's Decision no. 1292,
2009), the Board ruled that a claim reciting 50 to 300 units of
botulinum toxin for treating pain was a method of medical
It should be noted, however, that there have also been recent
cases where more specific dosage regimens have been held to be
patentable in Canada. In Merck & Co. v. Pharmascience
2010 FC 510, a claim to a 1.0 mg tablet taken as a daily dose was
held to be patentable subject matter on the basis that it is a
"vendible product" and no skill or judgment of a
physician is required. Similarly, in Merck & Co. Inc. v.
Apotex, 2005 FC 755, a claim directed to 70 mg of a particular
drug on a once-weekly dosing interval was also held to be
patentable subject matter. Based on these court decisions, a fixed
amount of a drug administered on a fixed schedule is not considered
a method of medical treatment and, therefore should constitute
patentable subject matter.
In view of the above-cited cases, it appears that the state of
protection available in Canada for dosage regimens is somewhat
unclear. For example, it appears that a claim directed to a unit
dosage form is patentable subject matter. Therefore, individual
claims in the same patent directed to 1.5 mg, 2.0 mg, 2.5 mg, or
3.0 mg tablets taken on a daily basis should constitute patentable
subject matter. However, collectively, such claims would provide
similar protection to a single claim directed to a dosage range
between 1.5 and 3.0 mg taken on a daily basis, which, considering
the current state of law, would not be patentable subject
Accordingly, for companies developing novel and inventive dosage
regimens, or other means for administering a medicine to a patient,
it would be prudent to consider alternative ways to claim the
invention. For example, including a list of specific single dosages
to support a separate claim to each of these amounts (note that
there are no excess claim fees in Canada, therefore including
hundreds or thousands of claims in a single application is not, at
least, financially prohibitive), or including kit and/or
pharmaceutical package type claims, are some of the strategies that
can be attempted. Regardless, speaking with a patent agent
specializing in this area prior to submitting a patent application
where the invention relates to how a medicine is administered is
The content of this article is intended to provide a general
guide to the subject matter. Specialist advice should be sought
about your specific circumstances.
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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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