FDA Revises Labeling Guidance to Clarify Clinical Pharmacology Recommendations

A new draft guidance document published by the US Food and Drug Administration (FDA) seeks to help sponsors with the "clinical pharmacology" sections that accompany an approved drug's labeling.

Background

Clinical pharmacology refers to how a drug is expected to affect a patient using the drug, and includes information obtained from pharmacodynamic and pharmacokinetic research (i.e. how a drug interacts with the body, and to what extent), as well as from adverse event and toxicology data obtained from clinical studies.

As FDA explains in its new revised draft guidance, Clinical Pharmacology Labeling for Human Prescription Drug and Biological Products--Considerations, Content, and Format:

"Optimal pharmacotherapy is driven by an understanding of a drug product’s clinical pharmacology and the clinical context in which the drug will be used. Important clinical pharmacology attributes to consider in therapeutic decision making include, but are not limited to, drug mechanism of action, pharmacodynamic (PD) effects (e.g., on target/pathway, and off target/pathway), and PK properties in a variety of settings and specific populations."

While pharmacology data is essential for the purposes of approval, it's also an integral parts of a drug's labeling as well. As explained in other guidance documents, such as Implementing the PLR Content and Format Requirements, clinical pharmacology data is used to inform prescribing decisions, prevent dangerous drug-drug interactions (DDIs), and warn consumers about risks associated with the drug.

All clinical pharmacology information should appear in the "CLINICAL PHARMACOLOGY" section of the drug labeling, though information that "is essential for prescribing decisions" may be contained elsewhere in the labeling, according to FDA.

Draft Guidance

FDA's new draft guidance—a revision of a 2009 draft guidance—is intended to clarify several aspects that were unclear to industry in the earlier draft.

For example, industry groups PhRMA and BIO both weighed in, asking for several dozen clarifications between them.  Pharmaceutical and biopharmaceutical companies Pfizer, Amgen, Merck, Johnson & Johnson, Sanofi, Boehringer Ingelheim and GSK all weighed in with dozens of additional, highly technical suggestions.

While FDA didn't provide much of an explanation as to what changes were made, it wrote that the draft guidance "outlines the use of subsections, headings and subheading to provide organization to the clinical pharmacology section [and] also emphasized the importance of providing variability measures related to pharmacokinetic measures and parameters, pharmacodynamics measures and other clinical pharmacology study results."

FDA also explains that while pharmacology information should, to the extent possible, be "concise to enable unambiguous application to patient care," some drugs may also warrant "expanded versions of this supportive information in the labeling" to support more accurate prescribing decisions through "sufficient detail."

Not all labeling information contained in the guidance will apply to every product, FDA noted.

Clinical Pharmacology Labeling for Human Prescription Drug and Biological Products —Considerations, Content, and Format (FR)