Measures laid out in letters to 17 companies would either have modest impact or face legal challenges, say industry experts.

President Donald Trump surprised pharma CEOs on Thursday with letters demanding they acquiesce to his most-favored drug-pricing scheme (see what we did there?) by the end of September, setting up a late-summer lobbying fight for the industry.

President Donald Trump has sent letters to pharmaceutical companies, aiming to compel them to lower drug prices in the US to match the lowest prices offered in other developed nations, a move that could significantly reduce costs and disrupt the current system of pharmacy benefit managers.