There is an article in the Wall Street Journal at
http://online.wsj.com/article/SB122696875770635577.html?mod=googlenews_wsj
that talks about this using Provigil as an example.
Apparently, the drug company
1. Came up with a new, improved version that lasts longer
2. Raised the price on the current version
3. Is planning to release the new version at a much lower price thus
4. Forcing most people to switch to the new version in the couple years before the generic comes out
5. Therefore, when the generic comes out, most people will be on the new, patent-protected version and presumably prefer that
Acccording to the article, "Cephalon [the company that make Provigil] acknowledges regularly increasing the price of its drugs, based on where in their lifecycles they are, market forces, its research-and-development costs and other factors."
The article also notes that "Provigil's price increase over the past four years has been almost four times steeper than the 4% compound annual growth rate of the average drug price during that period, according to a DestinationRx analysis of 2,570 brand-name drugs."
sho