Patent Appeal Board Allows Dosage Regimen Claims ' No Physician Skill Needed

• Published date: 26 January 2021
• Subject Matter: Intellectual Property, Patent
• Law Firm: Bereskin & Parr LLP
• Author: Ms Patricia Folkins and Shuo Xing

In the recent Commissioner's Decision Re Amgen Research (Munich) GmbH (2021 CACP 2), the Patent Appeal Board allowed medical use claims reciting a dosage range in Amgen's Canadian Patent Application 2,633,594 (the 594 application).

It is well known that in Canada, while methods of medical treatment are not patentable subject matter, medical use claims are considered patentable. Nevertheless, there have been several Federal Court decisions¹ where a claim directed to the exercise of professional skill or judgment, for instance a claim containing a dosage range, was held to be not patentable.² Consequently, CIPO issued the 2015 Revised Examination Practice Notice (PN 2015-01), which specified that where an essential element of a medical use claim prevents, interferes with or requires the professional skill of a physician, the claim is considered to encompass a method of medical treatment and is not patentable subject matter under s.2 of the Patent Act.

The claims in questions in the 594 application are directed to an antibody for use in the treatment of B cell non-Hodgkin lymphoma or B cell leukemia, wherein the antibody is for administration for at least 1 week in a daily dose of 10 μg to 80 μg per square meter patient body surface area. In the Final Action, the Patent Office recognised that determination of the duration of the treatment and selecting a dosage from within the recited range of 10 μg to 80 μg would not require the skill and judgment of a physician, since there is no indication that a particular duration or a fixed dose would not work for all subjects. Nevertheless, the Examiner determined that administration of the antibody based on square meter body surface area of a patient does require professional skill and judgment, citing PN 2015-01.

The Applicant successfully argued that calculation of a particular dosage based on body surface area is mere mathematical calculation that is within the skill of a technician and not a physician. The determination thus does not require professional judgment. The Patent Appeal Board also distinguished the invention in question from those of previous decisions such as Axcan and Commissioner's Decision Re Allergan (CD 1292). The Board noted that whereas in previous decisions a physician's skill and judgment is required to determine whether a particular dosage is appropriate for a particular patient, there is no evidence here to show that any dosage within the 10 μg to 80 μg range is inappropriate, since the...