On Jul. 16, 2020, the Tufts Center for the Study of Drug Development reported that although regulatory approval time for new drugs in the U.S. had shortened, the time needed, on average, to complete clinical development of those drugs is lengthening by a greater amount, leading to longer times to develop and bring new drugs to market in the country.

Average total time to conduct clinical studies and then complete the approval phase increased by 4.8 months from 2008-13 to 2014-18, according to Tufts CSDD, with mean clinical times increasing by nearly seven months and approval times dropping by nearly two months.

However, average combined clinical and approval time was 11% lower for drugs benefiting from expedited review by the Food and Drug Administration (FDA) compared to non-expedited review drugs during the same time, the study found.

Other findings from the study, based on 377 new drugs and biologics approved for marketing in the U.S., summarized in the July/August Tufts CSDD Impact Report include the following:

• Mean approval phase decreased by 1.9 months for all approved drugs during 2014-18, compared to 2008-13, while mean clinical phase increased by 6.7 months over the same period.
   
• Clinical development times varied substantially for the therapeutic areas with the most drug approvals during 2008-18.
   
• Total average clinical and approval time was 11% lower for expedited review compared to non-expedited review drugs during 2008-18.
   
• The mean number of participants per clinical trial in Phases I-III increased from 2008-13 to 2014-18, with the highest growth (9.2%) observed for Phase II.