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Much buzz has been generated by the recent Supreme Court of Canada decision in Sanofi v. Apotex (2008 SCC 61). Some of the key impacts of this case on patent agents, inventors, patent owners, and litigants are provided below (see headings).

The Decision

A detailed summary of this case is on our web site. In brief, Sanofi separated a chemical called an enantiomer from a known racemate. The racemate contained a mixture of equal amounts of two enantiomers. Sanofi filed a patent application for the purified D-enantiomer, clopidogrel bisulfate, which is now marketed under the trade name PLAVIX. The racemate had already been disclosed in an earlier patent that also included over a quarter million other compounds. The new patent application showed that Sanofi surprisingly determined that the enantiomer had beneficial properties, such as lower toxicity than the racemate. It had better platelet-aggregation inhibition activity than the other enantiomer. It was also better tolerated by patients. As a result, a new patent was granted because it was for a selection of an unexpectedly beneficial compound from the very large group of compounds in the earlier patent.

The new enantiomer patent stood up in Court against generic challenges that it was not novel or inventive in view of the earlier patent.

Canadian Agents and Foreign Agents who Instruct Canadian Prosecution

Agents have always argued for novelty and inventiveness of selection compounds. The Supreme Court has confirmed that such compounds are patentable.


A new two-part novelty framework is provided into which old arguments will be adapted: a) does the prior art disclose the compound and its special advantages (no trial and error permitted), and b) does the prior patent provide enough information to allow an ordinary skilled person to make the invention without an undue experimentation burden (“enablement”). This test also applies to other types of inventions.


The Court embraced a more flexible obviousness test that will consider a wider variety of factors, somewhat similar to the US KSR v. Teleflex test. In particular, the Court adopted the “obvious to try” standard as one of the factors. Examiners will have more scope to make objections but agents should also be able to use a broader variety of arguments in their responses.

Inventors and Companies that Own Patents

It is critical to establish unexpected beneficial properties for a selection compound before an application is filed. Tell your patent agent all the beneficial properties of new compounds so that your patent agent can explicitly list them in the patent application.

For all inventions, keep detailed written records of all experiments, including difficulties in making the invention. Such evidence may become critical to demonstrate inventiveness.

All lab books should be reviewed and signed by a witness, in accordance with the current best practice, so that data can be used to substantiate inventiveness arguments with the Patent Office or as evidence in litigation.

Further, prior art searches may be a valuable investment to establish the unpredictability of the art and to emphasize the advantages of the invention.


Pharmaceutical and biotech litigation will become focused on this court decision as companies argue over how to interpret and apply the new novelty and obviousness tests.

Canadian litigators, who are already looking to US and UK case law for jurisprudence that could influence Canadian courts, will dig even deeper now, complicating litigation. As noted above, the Court rejected a strict approach to obviousness and opened up the obviousness test to a consideration of all factors. This part of the decision was influenced by a recent US Supreme Court case, KSR v. Teleflex, that made a similar pronouncement that one should take “an expansive and flexible approach” and consider a variety of factors. The Canadian Court was also influenced by UK court cases that approved a line of argument, previously not allowed in Canada, that an invention will be invalid if it is "obvious to try."