Much has been written recently about low productivity in the pharmaceutical industry and the high cost of drug development. Over a 10-year period ending in 2000, only approximately 11% of compounds tested in humans across 10 large pharmaceutical companies were eventually approved for marketing in the United States and/or Europe. Attrition was highest during phase II (62%) but still significant in phase III (45%) and at the time of registration (23%). Clearly, given the high cost and time required for clinical development, these late-stage failures are unsustainable.