Philippine Pharma Price Prohibitions on Patented Potions

Todays' WSJ reports that "President Gloria Macapagal Arroyo imposed price controls on several branded drugs when their manufacturers failed to comply with a new law designed to lower retail prices."  On a quick review, I don't see anything in TRIPS that would restrict the ability of a state to set price controls on patented pharmaceutical products.  What am I missing?  I suppose the manufacturer might decide to exit the market under these circumstances, but there will be good reasons to stay in valuable markets like the Philippines.  Nor can I imagine a successful non-violation nullification or impairment claim succeeding here.  It just seems like too much to claim that under TRIPS states gave up their ability to regulate prices when there is nothing specific that does that.