The original maker of Viagra has not being ripped off. - of course they have. Money that was meant for the drug they made has gone to someone else. That is a rip off.
The fraudulent sale in no way affects the assets, inventory, or any other property of Pfizer. It's like you're claiming that they own the
potential sale, in which case they might as well sue anyone who intends to buy Viagra but changes eir mind before actually making the purchase.