FDA is often asked about the pace of drug approvals and how FDA review time for applications affects it. Since the Prescription Drug User Fee Act (PDUFA) was passed in 1992, FDA has met and often exceeded the vast majority of review-time goals established under the Act. New drug approval times also have been dramatically reduced (from a median of 22 months in 1992 to a median of less than 12 months in 1999), although a slight increase was seen for the year 2000. The charts below illustrate this and the relationship between FDA review time for New Drug Applications (NDAs) and actual, start-to-finish, drug approval times. All figures refer to approvals for New Molecular Entities (NMEs).
FDA Review Time: The time it takes FDA to review a new drug application. Review time goals are established under PDUFA.
Approval Time: Approval time is the time from first NDA submission to NDA approval. It includes the sum of: FDA review time for the first submission of an NDA to the Agency, plus any subsequent time during which a pharmaceutical sponsor addresses deficiencies in the NDA and resubmits the application, plus subsequent FDA review time.
New Molecular Entity (NME): A medication containing an active substance that has never before been approved for marketing in any form in the United States.
Priority New Drug Application (NDA): An application for a product determined to provide a significant therapeutic or public health advance. Priority NDAs have a 6-month FDA review performance goal.
Standard New Drug Application (NDA): A NDA for a product that is not designated as a Priority NDA. The performance goal for FDA review for a standard NDA is 10-12 months.Figure 1 shows the median time to approval for NMEs between 1986 and 2000.
The number of Priority NMEs, those with a 6-month review goal, reviewed in a given year impacts the median approval time for drugs. In 1999, 19 of 35 (54%) NMEs had priority designation. For 2000, only 9 of 27 (33%) of the NMEs had priority designation.
By definition, a drug's time to approval includes time that the NDA is under review by FDA, as well as any time it takes the pharmaceutical sponsor to address deficiencies identified by the Agency. Deficiencies can range from requiring new data analyses, to labeling revisions, to the need for conducting additional clinical studies. Some applications go through more than one cycle of NDA submission followed by an FDA action other than approval. The percentage of NMEs that are approved within 12 months of submission has remained relatively constant in recent years at around 40%. However, products with longer regulatory NDA histories with multiple review cycles can significantly affect aggregate time to approval for drugs in a given year. Figures 3 and 4 illustrate regulatory histories and cycles for individual products approved in 1999 and 2000. Each horizontal bar represents an approved application. Comparing the two figures side by side illustrates the influence that a few products approved in 2000, which had multiple or prolonged review cycles, had on the overall or median approval time for NMEs in that year. Several of these products took more than one year to have deficiencies addressed; one took over two years. [Note: The blue hatched boxes reflect additional response time that is not included in calculations of "approval times." It represents time that was not used by the sponsor for actual development (e.g. trials or data analyses) nor by FDA for review of the application. For example, a sponsor might need to locate a new source of raw material or even a new manufacturer for the product.]
In summary, the applications approved in calendar year 2000 do, in aggregate, have a higher median time to approval compared to other recent years. However, the data show that factors underlying the change do not include any slowing by FDA in its review of NDAs. Instead, the smaller percentage of priority applications in 2000 and the high number of applications with prolonged regulatory histories are responsible for the increase.
FDA/Center for Drug Evaluation and Research