Canada: Canadian Patent Disclosure Requirements Clarified

In a decision dated August 12, 2009, the Federal Court clarified the disclosure requirements in patent drafting. This case is important to patent owners as it makes clear that misinformation, lack of information or insufficient information to support the invention can be fatal to a patent's validity. In Ratiopharm Inc. v Pfizer Limited 2009 FC 711, the Federal Court found a patent that contained inaccurate information invalid on the basis of obviousness, lack of utility, insufficiency, invalid selection and Section 53(1) of the Patent Act (which provides that a patent is void when there were material misstatements willfully made in the patent for the purpose of misleading).

The case in question involved a claim to the besylate salt of the pharmaceutical ingredient amlodipine. The patent promised that the besylate salt had certain advantages over other salts that were "unexpected" and that it had a "unique" combination of properties that made it "outstandingly" suitable for pharmaceutical preparation of amlodipine. (para. 108) Such superlatives can often be found in patents, particularly in improvement patents, however, those superlatives are often accepted at face value or side-stepped as, in effect, puffery.

In the present case, the court looked closely at the disclosure and data in the patent in light of evidence presented at the trial. The Court considered whether the superlatives were justified and found that, contrary to the representations in the patent, the unique or outstanding properties of the besylate salt were shared with other salts as well. The patent omitted data that would have shown similar properties in other salts. The court noted that the superlative words such as "unique and outstanding" were not words used by the inventors respecting the besylate salt but were words that had been selected by the patent department who had drafted the patent.

As amlodipine and its pharmaceutically acceptable salts had been claimed previously, the Court considered whether the claim to amlodipine besylate qualified as a selection patent. The Court concluded it did not merit such status as "adjectives and adverbs without solid foundation cannot create a 'selection patent' where none in fact exists". (para.179) Neither the patent itself, nor the evidence demonstrated the besylate salt to be sufficiently superior to the other salts to qualify.

The Court also conducted a utility analysis based on the promise that amlodipine besylate was superior to other salts. It accepted the evidence at trial that the besylate salt did not deliver the superior performance promised by the patent. The court went on to say that an inventor has a duty to act uberrima fides, to give all information known to him that will enable the invention to be carried out to its best effect as contemplated by him. On the evidence at trial, the promised utility of the invention was not fulfilled.

The court further analyzed the patent under sufficiency, in accordance with Patent Act requirements to correctly and fully describe the invention and its operation or use as contemplated by the inventor. It noted that courts in the past had focused on whether the patent itself provided sufficient information to enable a person skilled in the art to make use of the invention as contemplated by the inventor. On the evidence, the court accepted that what the inventor contemplated, and what the patent disclosed, were not one and the same. It noted that other courts, when assessing the sufficiency of the disclosure in the absence of other evidence, had to assume that the words of a specification coincided with what the inventor contemplated. In this case, the evidence showed that the specification of the patent did not disclose the invention, as contemplated by the inventors. The patent was found invalid as failing to correctly and fully describe the invention as required by the Patent Act.

The court also analyzed the patent under Section 53.1 of the Patent Act, which indicates that a patent will be void if the patentee willfully provides in the specification more or less than is necessary, so as to mislead a person skilled in the art. The court found a breach of Section 53 in that the patentee, Pfizer, (i) omitted to mention the stability of another salt and stated that the salt was unsuitable for tablet formulation, when it was in fact suitable, (ii) omitted test data demonstrating the suitability of other salts and (iii) added a statement that none of the salts had been found to be satisfactory, when in fact that was not the case. The court concluded there were misstatements that served to enhance the alleged uniqueness and outstanding characteristics of the besylate salt and that these misstatements and the selection of superlative descriptive words were the work of patent draftsmanship and not of the inventors. The court also concluded that proper disclosure was essential in a patent and that intent to mislead could be inferred. The court found sufficient intent to make such misleading statements based on the evidence.

Counsel who are drafting or supervising the drafting of patent applications are well advised to carefully consider the disclosure requirements set out in this case. The Court quoted the inventor who stated that "a patent has to be clear, honest and right" with approval. (para. 55) The patent specification must describe the invention made by the inventor, not a super version of that invention. The patent drafter cannot choose patent data in support of the invention that omits relative data that might detract from a promise of uniqueness or special attributes. Careless patent drafting or inflating an invention so as to increase its patentability, risks not only a finding of invalidity for insufficient or inadequate disclosure but also a finding of fraud by the patentee itself. The conclusion to be drawn from this case is that care must be taken by those drafting a patent. The patent specification and claims must correctly and fully describe the invention rather than a wished-for invention. Disclosure in support of the invention should be full and frank and not selective and incomplete.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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