1 May 2011PatentsKatie Wang

Attacking the validity of selection patents

The conclusion is not surprising: a selection patent will not receive special treatment. Its validity is vulnerable to attack on any of the grounds provided in the Patent Act. Accordingly, a determination that the conditions for a select patent have not been met does not constitute an independent basis upon which to attack the validity of the patent (Eli Lilly Canada Inc. v Novopharm Limited).

In this case, Eli Lilly commenced an action for patent infringement against Novopharm with respect to Lilly’s ‘113 patent. The ‘113 patent is a selection patent for the compound olanzapine (sold under the brand name Zyprexa), used to treat schizophrenia.

Novopharm defended the infringement allegation made against it and counterclaimed on the ground that the ‘113 patent was not a valid selection patent. Novopharm’s other grounds included, inter alia, anticipation, double patenting and obviousness.

The concept of selection patents is well known in the context of chemical compounds. In general terms, a selection patent is one whose subject matter (compounds) is a fraction of a larger known class of compounds that was the subject matter of a prior patent (the originating or genus patent).

In this case, the ‘113 patent identifies an already-patented compound disclosed in an earlier Canadian patent (the ‘687 patent) obtained by Lilly on the basis that it allegedly manifests unexpected, substantial and special properties in comparison with the other members of its chemical family.

Trial decision

The trial judge examined the ‘113 patent specifically in relation to the proclaimed advantageous qualities of olanzapine and divided the advantages into two categories: the superiority of olanzapine over the other compounds of the ‘687 patent and its superiority over other known anti-psychotic drugs.

The trial judge framed the main question as “is the ‘113 patent a valid selection patent?” and held that a selection patent is valid if it discloses to the public something new and useful in exchange for a further monopoly on the already patented compound.

The inventor of a selection patent must disclose an invention over and above what was disclosed in the ‘genus’ patent covering the selected compound. Relying on the principles set out in the British case of Re I.G. Farbenindustrie A.G.’s Patents (1930), which were referred to by the Supreme Court of Canada in Apotex Inc. v Sanofi-Synthelabo Canada Inc., the trial judge set out the steps for analysing the validity of the ‘113 patent as follows:

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