For every billion dollars spent on pharmaceutical research and development since 1950, the number of new drugs approved has fallen by half roughly every nine years, meaning a total decline by a factor of 80. They called this Eroom’s Law, because it resembled an inversion of Moore’s Law. 

That’s not a promising statistic and one of the main reasons why the FDA typically approves less than 10 new drugs every year.

via Why Are So Few Blockbuster Drugs Invented Today?