Today, the Canadian Supreme Court invalidated the VIAGRA patent for lack of adequate disclosure.
The patent was invalidated without the need to prove fraud or willful intent to mislead.
The bottom line is that the widely used strategy to limit the information contained in a patent application (and maintain the secrecy of certain information relevant to the person skilled in the art) can result in the invalidity of the resulting patent.
We refer you to the following passages:
“[5] At the time of Pfizer’s patent application, Pfizer had conducted tests that demonstrated that sildenafil was effective in treating ED. None of the other compounds in Patent ’446 had been shown to be effective in doing so. Although Patent ’446 includes the statement that “one of the especially preferred compounds induces penile erection in impotent males” (A.R. vol. X, at p. 173), neither the disclosure — the descriptive portion of the patent application — nor the claims specify that sildenafil is the compound that works. Nowhere in the patent application is it disclosed that the compound that works is found in Claim 7 or that the remaining compounds in the patent had not been found to be effective in treating ED.”
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“[31] The issues in this appeal are best understood by reference to the fundamental principles underlying the patent system. As the courts below noted, sufficiency of disclosure lies at the very heart of this system. If the issues are viewed through this lens, the case becomes more straightforward, and the conclusion flows easily from this principle.
[32] The patent system is based on a “bargain”, or quid pro quo: the inventor is granted exclusive rights in a new and useful invention for a limited period in exchange for disclosure of the invention so that society can benefit from this knowledge. This is the basic policy rationale underlying the Act. The patent bargain encourages innovation and advances science and technology. Binnie J. explained the quid pro quo as follows in AZT, at para. 37:
A patent, as has been said many times, is not intended as an accolade or civic award for ingenuity. It is a method by which inventive solutions to practical problems are coaxed into the public domain by the promise of a limited monopoly for a limited time. Disclosure is the quid pro quo for valuable proprietary rights to exclusivity which are entirely the statutory creature of the Patent Act.”
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“[56] Pfizer submits that s. 58 of the Act allows courts to consider valid claims separately from those that are not valid. Implicitly, Pfizer is suggesting that under s. 58, where a valid claim exists, the consideration of the disclosure requirements can be limited to that claim. However, this is a misinterpretation of s. 58. Section 58 simply states that valid claims survive in the face of one or more invalid claims. This section is engaged once it has been determined, on the basis of the patent as a whole, whether the requirements, including the disclosure requirements, have been complied with. Section 58 does not allow a court to consider the validity of a single claim — Claim 7 in this case — independently of the rest of the specification, even if the claim in question is the only one that may be valid. This section is engaged only after the validity analysis is carried out.”
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“[65] As required by s. 2 of the Act, an invention must be novel. In the instant case, the invention is not sildenafil, per se, because this compound was already known. In fact, Pfizer had been investigating sildenafil as a cardiovascular drug when it first suspected that the compound would be useful in treating ED (R.F., at para. 13). The invention is therefore not sildenafil, but the use of sildenafil to treat ED.
[66] In this case, if we consider the specification as a whole, there is nothing to support the view that the use of sildenafil for the treatment of ED is a separate invention from the use of any of the other claimed compounds for that same purpose. No specific attributes or characteristics are ascribed to sildenafil that would set it apart from the other compounds. Even if we take into consideration the fact that sildenafil is an “especially preferred compound”, there is still nothing that distinguishes it from the other eight “especially preferred compounds”. The use of sildenafil and the other compounds for the treatment of ED comprises one inventive concept.
[67] In fact, the patent itself suggests that the entire class of claimed compounds will be effective in treating ED. The first sentence of the specification states: “This invention relates to the use of a series of [compounds] for the treatment of impotence” (A.R. vol. X, at p. 164 (emphasis added)). The following appears on the second page of the specification: “Unexpectedly, it has now been found that these disclosed compounds are useful in the treatment of erectile dysfunction.” And page 11 of the specification contains this statement:
Thus the invention includes a pharmaceutical composition for the curative or prophylactic treatment of erectile dysfunction in a male animal, including man, comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable diluents, or carrier. [Emphasis added; A.R., vol. X, at p. 174.]”
You can read Robert Brouillette’s interview granted to Droit Inc. (in French) by clicking here.