The question I'd ask is, when a company has made billions and has all the manufacturing equipment to make a product paid for, and their product was going off patent, wouldn't it be worth their while to lower the price that generic companies couldn't compete?
While some people will pay the difference to go with the name brand, I've got to believe the likes of Merck could still be very profitable selling Keytruda at prices a generic couldn't profit at because of the investment require to make it and gain approval of the generic form.
While this may violate their business model, they've made tens or hundreds of billions, why not make a little less, but keep all the business.
Gary