On January 25, 2007, Thailand’s interim government issued compulsory licenses–which require 
    manufacturers to license generic versions of their patented drugs–for two Western medicines: 
    Kaletra, an advanced anti-AIDS medicine manufactured by Abbott; and Plavix, a blood-thinning 
    treatment to help prevent heart disease, produced by the France-based Sanofi-Aventis and U.S. 
    firm Bristol-Myers Squibb. These attacks were preceded in November 2006 by a violation of 
    Merck’s patent on the anti-AIDS drug Stocrin.[5] The government threatened to break 
    patents on eleven more drugs.[6] Explaining the rationale behind Thailand’s decision, health 
    minister Mongkol Na Songkhla said that “the move is permissible under international trade 
    rules in the event of national public health emergencies. . . . We have to do this because we 
    don’t have enough money to buy safe and necessary drugs for the people under the government’s 
    universal health scheme.”[7]

Perhaps "evergreening" is also an issue in the USA that might keep prices high for a long time?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680578/