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# FDA Told: ‘Generally Accepted’ Often Isn’t
- URL: https://www.fdaweb.com/fda-told-generally-accepted-often-isnt/
- Published: 2023-07-25T12:00:00.000Z
- Updated: 2026-09-14T18:46:03.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5154948

The National Center for Health Research (NCHR) says that while it supports FDA efforts to be flexible and provide a more open application of scientific and regulatory judgment when conducting nonclinical studies that determine *in vitro* safety and efficacy, it cannot agree with an agency draft guidance on using generally accepted scientific knowledge (GASK) as the sole source of nonclinical data in NDAs or BLAs. The comment [letter](https://www.regulations.gov/comment/FDA-2023-D-1618-0008?ref=fdaweb.com) says that permitting GASK as the sole or primary evidence “would often create a level of ambiguity regarding a drug’s true pharmacologic, distributive, and toxicologic effects….. NCHR strongly encourages that the GASK used be **(1)** long-standing, **(2)** uncontroversial, and **(3)** scientifically robust.” The organization says it strongly urges FDA to revise the proposed GASK guidance to require comprehensive and precise language on when using GASK by the sponsor is appropriate.

In its [response](https://www.regulations.gov/comment/FDA-2023-D-1618-0005?ref=fdaweb.com), the Physicians Committee for Responsible Medicine (PCRM) says FDA could maximize the use of GASK by providing more comprehensive examples of its application in different contexts and to communicate these recommendations to sponsors effectively. PCRM also recommends that FDA host public meetings or listening sessions for drug and product sponsors to share their examples of GASK use.

Pharmaceutical Research and Manufacturers of America (PhRMA) [says](https://www.regulations.gov/comment/FDA-2023-D-1618-0006?ref=fdaweb.com) GASK is not well defined in the draft guidance, in particular on what information would be considered non-product specific. “PhRMA believes that appropriately defining what constitutes GASK is critical to ensuring that the GASK concept can be used to avoid conducting unnecessary studies but not be used as an end-run around intellectual property protections and the existing legal and regulatory framework intended to facilitate innovation. PhRMA says it encourages the agency to:

- clarify that it does not intend to, and the guidance does not create, a new, abbreviated pathway for biologics that do not meet the statutory criteria for biosimilar or interchangeable BLAs;
- more clearly define GASK and explain that it does not include information generated about a specific product or class of products;
- clarify that GASK may not be based on non-product-specific published literature that references product-specific published literature; and
- clarify that the submitting sponsor must substantiate that such information is GASK (for example by showing that the information appears in at least two published pieces of literature such as a textbook or journal article) and that GASK cannot be based solely on an assertion by the applicant or an expert.