The US Food and Drug Administration (FDA) on Thursday released a new draft guidance intended to help sponsors report physiologically based pharmacokinetic (PBPK) analyses to the agency in a standardized format.

PBPK Analyses

According to FDA, "PBPK analysis uses models and simulations that combine physiology, population, and drug characteristics to mechanistically describe the [pharmacokinetic] PK and/or pharmacodynamic (PD) behaviors of a drug."

These analyses, FDA says, can also inform other decisions about future clinical pharmacology studies and dosing recommendations, and are often used to support investigational new drug applications (INDs), new drug applications (NDAs), biologics license applications (BLAs) and abbreviated new drug applications (ANDAs).

Draft Guidance

"Because of the lack of regulatory guidance, the format and content of PBPK analyses that are submitted to the FDA vary significantly across drug developers," FDA writes.

As such, FDA says it was necessary to standardize the format and content of PBPK study reports in order to improve the agency's efficiency and consistency in assessing them.

In the draft guidance, FDA proposes a six-part format for PBPK study reports that includes a section for an executive summary, introduction, materials and methods, results, discussion and appendices.

However, FDA acknowledges that the amount of data included in each section will vary significantly depending on when the analyses are done, the agency says it still recommends completing each of the sections based on the data available.

Additionally, the section on materials and methods is further broken down into five sub-sections:

1. Overview of modeling strategy
2. Modeling parameters
3. Simulation design
4. Electronic files and other documentation
5. Software

While FDA does not have any specific requirements for the software used in PBPK modeling, the agency asks that sponsors submit information on the software they have chosen in a table.

FDA