Long-time readers know I hold a special place in my heart for discussion of IP around medicines. The basic idea of patenting is that you get a government-granted monopoly in exchange for disclosing your innovation. The Court held that Pfizer had not fulfilled its part of that bargain and thus its (Canadian) patent was invalid.

Geist says that the Court's decision rested on the notion that the patent claims themselves were not sufficient descriptive to permit a skilled person to replicate the invention that is supposedly disclosed. Patent critics have for many years railed against badly written patent claims and the fact that examiners, particularly in the US, seem willing to let patents go with badly drafted claims. Here we have a clear situation of a high Court rejecting that kind of sloppy (inadequate) patent claims construction.

I don't think that the Canadian decision will affect Pfizer's patents in other countries (e.g. the US) but practically once a generic version of a drug is manufactured it's impossible to stop its trans-national shipment. Gods help us we'll probably see an uptick in spam emails for "generic Viagra" now.