Generally Accepted Scientific Knowledge in Drug Applications

The FDA has received an increasing number of questions regarding the extent to which generally accepted scientific knowledge (GASK) may be relied on for drug or biological product approval. Therefore, the agency published a draft guidance which describes instances in which it may be appropriate to rely on GASK to meet certain nonclinical safety requirements for new drug applications. According to the FDA, this may result in "streamlined product development that avoids unnecessary animal testing, decreases a drug’s development costs, and quickens the drug’s time to approval and marketing — and thus, its availability to patients".

Examples of GASK

GASK means medical or scientific information that is generally accepted by experts qualified by scientific training and experience in the relevant field, including FDA experts. Generally, "GASK is based on widely accepted scientific principles that are typically long-standing. In addition, it may also be possible for GASK to be based on a sufficiently large volume of scientific studies/information that would be applicable beyond the specific instances in which that information was developed", says the agency.

The information that supports the nonclinical safety of a drug and that must be submitted in the application can include references to GASK instead of or in addition to, specific studies conducted with respect to the drug. In such cases it might be unnecessary to conduct certain nonclinical studies.

The guideline provides two examples of GASK in which sponsors have relied on GASK in their product development programs to meet relevant approval requirements:

• Substances Typically Present in a Healthy Human Body: Where a product contains a substance (either naturally derived or synthesized) that occurs naturally in the body, and sponsors have relied on GASK regarding that substance and its known effect on biological processes instead of conducting certain nonclinical studies
• GASK Regarding an Altered Biological Mechanism or Pathway: Where a sponsor has demonstrated a drug’s impact on a particular biological pathway, and then relies on GASK regarding that impact to conclude that certain nonclinical studies are not necessary to support approval and labeling of the drug.

If a sponsor thinks that certain information is GASK, the sponsor should submit a rationale to the FDA as early as possible in product development to obtain feedback with respect to the proposed regulatory strategy for approval. The submission should include relevant evidence supporting GASK, including textbook excerpts and/or non-product-specific published literature.

More information is available in FDA´s draft Guideline Generally Accepted Scientific Knowledge in Applications for Drug and Biological Products.