SCC invalidates Viagra patent, reiterates basic patent principle

The Supreme Court of Canada has just released a decision today in which it voids Pfizer’s patent for viagra.

The SCC restated the basic principle of the patent system:

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 issues in this case must be considered in light of the quid pro quo: Is the public getting what it ought to be getting in exchange for exclusive monopoly rights?

The Court ruled that Pfizer did not meet the disclosure requirement. The Viagra patent lists different classes of compounds, and the wording of the patent did not specify which compound was useful to treat erectile dysfunction.

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), the specification does not indicate that sildenafil is the effective compound, that Claim 7 contains the compound that works, or that the remaining compounds in the patent had been found not to be effective in treating ED. The claims were structured as “cascading claims”, with Claim 1 involving over 260 quintillion compounds, Claims 2 to 5 concerning progressively smaller groups of compounds, and Claims 6 and 7 each relating to an individual compound.

Pfizer defended itself by claiming that anybody just had to test the 2 final compounds and they’d figure it out. The SCC didn’t buy that and voided the patent.

[…]the public’s right to proper disclosure was denied in this case, since the claims ended with two individually claimed compounds, thereby obscuring the true invention. The disclosure failed to state in clear terms what the invention was. Pfizer gained a benefit from the Act — exclusive monopoly rights — while withholding disclosure in spite of its disclosure obligations under the Act. As a matter of policy and sound statutory interpretation, patentees cannot be allowed to “game” the system in this way. This, in my view, is the key issue in this appeal. It must be resolved against Pfizer.

The Viagra patent is set to expire in 2014, so the generic producers get at about a 2-year head start in the market.