How Well Does Canadian Law Protect Information Products? The Case Of Patents Over Diagnostic Methods

• Published date: 08 February 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Osler, Hoskin & Harcourt LLP
• Author: Mr Vincent De Grandpré and Leah McGurn

Precision medicine ' tailoring medical treatment to a patient's genetic characteristics ' has the potential to greatly improve health care. Researchers and life sciences companies are committing significant resources to developing therapies whose success turns on the presence of biomarkers identified with diagnostic tests. Oncology is one field where these investments are widespread, with researchers seeking to bring insight into the genomic mutations that drive cancer.

Protecting the technical contributions of inventors, and encouraging such valuable investments, is the main purpose of patent law. However, a 2021 Australian case, Ariosa Diagnostics, Inc. v Sequenom, Inc. (Ariosa Diagnostics), illustrates the difficulties of enforcing patents over diagnostic methods.¹ The Australian court held that Sequenom's invention over a method for detecting fetal DNA in a maternal blood sample was eligible for patent protection, but it was not infringed by a competitor who made the patented test available to Australians but carried out the diagnostic method outside of the country.

The patentee Sequenom may well have fared better in Canada. Recent Canadian legal developments broadening patentable subject-matter have gone a long way toward protecting diagnostic inventions. Moreover, the Supreme Court has endorsed the view that Canadian patent law should prohibit acts that deprive patentees of the benefit of their invention. On these grounds, Canadian patent law appears well tuned to balance effective patent protection for diagnostic method inventions with countervailing policy objectives such as preventing patents from pre-empting entire fields of scientific research.

The challenge of enforcing patents over diagnostic methods

In the late 1990s, Sequenom developed and patented a method for detecting fetal DNA in maternal blood samples. In Ariosa Diagnostics, the Full Court of the Federal Court of Australia held that the claims in Australian Patent No. 727919 (AU 919) fell within the concept of a manner of manufacture, being an artificially created state of affairs of economic utility and therefore patentable subject-matter.² Fetal DNA is a naturally occurring phenomenon but, in the Court's view, a method for identifying and discriminating between maternal and fetal nucleic acid went beyond a mere discovery of a naturally occurring phenomenon.³

The Full Court was also called upon to decide whether the defendant Ariosa Diagnostics infringed AU 919 by practising the gene-based diagnostic method. The evidence showed that health care professionals drew blood samples from...