A New Look At United States Drug Development and Approval Times

Clinical development and regulatory approval times for new chemical entities (NCEs) approved in the United States through 1995 were analyzed by both year of new drug application (NDA) approval and year of NDA submission. Results and conclusions from a recent General Accounting Office (GAO) report on US new drug approval times by year of NDA submission for NDAs submitted during 1987 to 1992 were examined and the analysis was extended using data collected by the Tufts Center for the Study of Drug Development (CSDD). The hypothesis that approval times declined by year of NDA submission for 1987 to 1992 submissions, independent of such factors as the therapeutic type and significance of the drugs reviewed, is not supported by the evidence. Mean times from first testing in humans, investigational new drug application (IND) filing, and initiation of Phase III testing to NDA submission increased over time for NCEs by period of NDA submission. When analyzed by year of approval, mean approval times for the 1994 and 1995 NCE approvals were markedly lower than mean approval times for previous years (1.7 y for 1994--1995 compared to 2.7 years for 1990--1993). Mean time from IND filing to NDA submission, however, was notably longer for the 1994 and 1995 approvals than for approvals in earlier years (7.2 y for 1994--1995 compared to 5.5 y for 1990--1993).