CIPO Issues New Guidance on Medical Use Patent Claims

On June 10, 2013, the Canadian Intellectual Property Office (CIPO) published its practice notice entitled "Examination Practice Respecting Medical Uses"¹ following the Federal Court of Appeal Decision in Canada (Attorney General) v. Amazon.com. This notice builds on guidance set out in the Manual of Patent Office Practice (MOPOP)², as well as a recently issued notice from CIPO respecting purposive construction³, as it relates to the examination of medical use claims as patentable subject matter under the Patent Act. In particular, the notice specifically addresses claims embodying dosage regimens and ranges. This notice follows upon a public consultation from the spring of 2012.

Medical Use Claims: Overall Approach

The notice sets out CIPO’s position that medical use claims are generally permitted as long as they do not equate to medical or surgical methods (while also satisfying all other requirements of patentability)⁴. The notice indicates that in order to assess whether the subject-matter of a medical use claim is statutory, it is necessary to first determine the essential elements of such a claim through purposive construction.

Step 1: Claims Analysis

The notice provides that purposive construction is the sole approach to claim analysis, in place of other all approaches (CIPO specifically singles out the "contribution approach" set out in MOPOP Chapter 13 as an approach that is not to be used). To perform purposive construction, an examiner must be able to identify both the problem the inventors set out to address and the solution disclosed.

The notice goes on to specifically comment on how to assess medical use inventions. When the problem faced by the inventor relates to "what" to use for a treatment, the solution, according to the notice, is generally provided by an element or set of elements in a claim that embodies a treatment tool. The notice provides specific examples of such a treatment tool as a compound, composition, formulation or a dosage unit form.

Where the problem relates to "how" to administer or refine a treatment, the notice provides that the solution embodied in the essential elements of the patent claim will likely place a limit on the professional skill or judgment of a physician.

This distinction in characterizing the problem the invention solves as either "how" or "what" will determine whether the claims will be statutory subject matter, as discussed below.

Step 2: Assess the Patentability of the Subject Matter

Once the essential elements of a patent claim have been identified, the notice provides that the next step is to assess the subject matter of the claim for patentability. The notice provides a specific example of a non-statutory medical use claim, referring to a recent Federal Court decision⁵ which determined that a method of medical use invention includes any invention preventing physicians from exercising their skill and judgment in using a known compound for an established purpose.

According to CIPO, such essential elements that point to "how" to treat a patient, limiting a physician’s skill or judgment include those that (i) provide details of a dosing schedule, (ii) represent a range of potential dosages that a patient may receive (which is distinct, according to CIPO, from a "range of dosages forms"); and (iii) narrow treatment to a patient sub-population or administration site.

Therefore, the presence of claims that recite dosage regimens or ranges will not necessarily render them non-statutory. However, if it is determined after purposive construction that a dosage regimen or range is an essential element of a claim, CIPO will consider the claim to cover a method of medical treatment.

The notice will be the subject of further discussion and interpretation. In the meantime, applicants drafting claims should refer to the notice in an effort to avoid rejection on the basis of non-patentable subject matter.

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¹ Issued as Exam Memo PN2013-04.

² MOPOP 17.02.03.

³ An accompanying Exam Memo PN2013-02 setting forth CIPO’s position on purposive construction of patent claims was issued on March 8, 2013.

⁴ Tennessee Eastman v. Commissioner of Patents, 1972, 8 C.P.R. (2nd), 202 (S.C.C.); ImperialChemical Industries Ltd. v. Commissioner of Patents, 1986, 9 C.P.R. (3rd), 289 (F.C.A.)

⁵ Janssen Inc. v. Mylan Pharmaceuticals ULC, 2010 FC 1123.