There has been a significant amount of uncertainty in Canada regarding the patentability of use claims which include dosages and dosage regimens. Nearly two years have passed since a panel of the Federal Court of Appeal (FCA) in Cobalt v Bayer flagged the patentability of methods of medical treatment as being worthy of full consideration by the FCA or the Supreme Court of Canada (click here for more details) and no such matters have yet come before these courts. For guidance, patentees have thus been forced to turn to a hodgepodge of lower court decisions and a practice notice (PN 2015-01; click here for more details) issued by the Canadian Intellectual Property Office (CIPO).

While we await further direction from the courts, the Patent Appeal Board (PAB) in the recent C.D. 1418 decision of the Commissioner of Patents, has provided some welcome good news for those seeking to patent dosage regime innovations in Canada.

The claims at issue were directed to the use of a formulation comprising calcitonin (CT) in combination with one or more specifically listed oral delivery agents for the treatment of a disorder responsive to the action of CT. The claims also included the feature of oral administration of the formulation from about 5 minutes to 2 hours prior to a meal. The PAB held this claimed range of time was an essential element. CT is a known peptide hormone and the use was also known. What were argued to be inventive were advantages associated with the oral administration at the short interval prior to a meal.

The CIPO practice notice PN 2015-01, mentioned above, provided the example that a dosing schedule encompassing a range is an essential element that is unpatentable for preventing, interfering with or requiring the professional skill of a physician. The impact of this guidance appears to have been lessened by the result in C.D. 1418.

In C.D. 1418, the PAB stated that “the physician’s skill and judgment are not expected to be exercised within the scope of the claims once the physician has decided to prescribe the oral CT formulation shortly before a meal” [paragraph 38]. In particular, regarding the timing, the PAB stated that the person of skill in the art “would appreciate that any time during the recited time window would overcome the negligible plasma levels observed when administering an oral formulation of CT with a meal, so that no physician judgement is required in selecting a time within this range” [paragraph 38].

The result in C.D. 1418 falls in line with the reasons of the Federal Court in AbbVie v Canada (AG) which distinguished between cases where professional skill and judgment is exercised within the claim (for example, where adjustments would be required) and those where it is not (for example, a physician determining whether a claimed use is appropriate for a patient). It is also in agreement with reasons in the earlier C.D. 1409 decision in which the PAB stated that while activities involved in physician monitoring may be needed in an actual clinical setting, they were not monopolized by the claimed (fixed) dosage regimen and thus any judgment or skill would be outside of the claim.

The claims at issue in C.D. 1418 were ultimately rejected for being obvious, but this decision may signal a possible further softening of CIPO’s stance on the patentability of medical use claims. However, there still exists uncertainty in the law and it remains to be determined whether a Court would find such claims to be patentable subject-matter.