What does it cost to develop a drug?

From the Economist June 11th 2005

According to an oft-quoted figure from the Tufts Centre for the Study of Drug Development, in Medford, Massachussetts, developing a drug typically costs $900m abnd takes 15 years. Only 1 in 1,000 compounds tested makes it into human trials, and only one in five of those emerges as a drug.