Pfizer wrote a patent application for one of its drugs and prosecuted it through to issuance in Canada. However, in that patent application, Pfizer’s Canadian patent attorneys/agents evidently failed to disclose the best mode of making and using the invention by “…failing to identify the active compound in the drug.” The drug is Viagra, a popular and profitable drug that enhances male sexual performance.
While this ruling is under Canadian patent law, this is a cautionary tale to all who seek patent protection. You must disclose the best mode of making and using the invention pursuant to 35 USC 112, Paragraph 1. The America Invents Act does not change that requirement.
It will be interesting to see what happens to the US patent for Viagra in the face of the Canadian ruling.