Investigating Rates of Food and Drug Administration Approvals and Guidances in Drug Development: A Structural...

Area of Science:

• Pharmacoeconomics and Drug Development
• Regulatory Science
• Time Series Analysis

Background:

• The number of FDA drug/biologic approvals (original and supplemental ANDAs, BLAs, NDAs, Biosimilars) has significantly increased.
• Concurrently, the volume of issued FDA guidances has also risen, prompting an investigation into their potential relationship.

Purpose of the Study:

• To analyze the time-series structures of FDA drug/biologic approvals and guidances.
• To determine if there is a statistically significant relationship between the number of approvals and guidances issued by the FDA.

Main Methods:

• Employed Structural Breakpoint (SBP) and Cointegration (CI) analyses to assess the relatedness of the two time series.
• Conducted descriptive statistical tests including nonparametric correlation, decomposition, unit root testing, stationarity, and maximum order of integration.

Main Results:

• Identified structural breaks in approvals (1983, 1989, 1996, 2004, 2012) and guidances (1995, 2012).
• Found a medium correlation, nonstationarity, and cointegration (I(1)) between approvals and guidances, indicating shared underlying dynamics.
• Observed additional similarities such as seasonal variation in both time series.

Conclusions:

• This study is the first to empirically link FDA guidances and drug/biologic approvals.
• The structural similarities suggest a deeper relationship and a potential long-run equilibrium between guidances and approvals.
• Highlights opportunities for future research into factors influencing FDA approval and guidance rates.