The U.S. Food and Drug Administration (FDA) recently issued its final guidance on the definition and labeling of medical foods, entitled "Frequently Asked Questions About Medical Foods: Second Edition."[1] According to the Federal Register notice that announced the availability of the new guidance, the final guidance provides FDA's responses to additional questions regarding the definition and labeling of medical foods and updates some of the responses in the August 2013 draft guidance.[2] Overall, however, the final guidance essentially reiterates the information and requirements in the draft guidance. Of particular note, the agency continues to have a narrow interpretation of what constitutes a disease or condition that has "distinctive nutrient requirements" under the medical food definition. As the guidance document represents FDA's enforcement policy, and the final guidance has demonstrated FDA's unwillingness to change its stance on the definition of medical foods, companies that manufacture or market medical foods should take note and be prepared for potential enforcement actions.

This post provides the general regulatory background for medical foods, summarizes the key components of the final guidance, and also discusses a few recent Warning Letters issued by FDA to companies that manufacture or market medical foods.

Overview of Medical Foods

A medical food, as defined in section 5(b)(3) of the Orphan Drug Act (21 U.S.C. 360ee(b)(3)), is "a food which is formulated to be consumed or administered enterally under the supervision of a physician and which is intended for the specific dietary management of a disease or condition for which distinctive nutritional requirements, based on recognized scientific principles, are established by medical evaluation." FDA considers the statutory definition of medical foods to narrowly constrain the types of products that fit within this category of food. Medical foods are a distinct category of foods and have been further defined in the FDA regulations as set forth below:

  • It is a specially formulated and processed product (as opposed to a naturally occurring foodstuff used in its natural state) for the partial or exclusive feeding of a patient by means of oral intake or enteral feeding by tube;
  • It is intended for the dietary management of a patient who, because of therapeutic or chronic medical needs, has limited or impaired capacity to ingest, digest, absorb, or metabolize ordinary foodstuffs or certain nutrients, or who has other special medically determined nutrient requirements, the dietary management of which cannot be achieved by the modification of the normal diet alone;
  • It provides nutritional support specifically modified for the management of the unique nutrient needs that result from the specific disease or condition, as determined by medical evaluation;
  • It is intended to be used under medical supervision; and
  • It is intended only for a patient receiving active and ongoing medical supervision wherein the patient requires medical care on a recurring basis for, among other things, instructions on the use of the medical food.[3]

Importantly, medical foods are exempt from labeling requirements for nutrient content claims and health claims that apply to conventional foods. Nonetheless, manufacturers of medical foods are still subject to other applicable FDA requirements, including requirements relating to food safety (e.g., current Good Manufacturing Practices (21 C.F.R. Part 117, Subpart B) and preventive controls (21 C.F.R. Part 117, Subpart C).

FDA's Final Guidance Continues to Narrowly Define Medical Foods

In the original 2013 draft guidance, FDA stated that it considered inborn errors of metabolism (IEMs) to be diseases or conditions that a medical food could be used to manage. IEMs was defined by FDA as including inherited biochemical disorders in which a specific enzyme defect interferes with the normal metabolism of protein, fat, or carbohydrate. On the other hand, the agency pointedly noted that it did not consider pregnancy, diabetes, and essential nutrient deficiencies (e.g., scurvy, pellagra) to be diseases or conditions for which a medical food could be labeled and marketed because they do not present distinctive nutritional requirements.

FDA's final guidance continues to narrowly define the scope of medical foods. For example, in responding to a question about whether there are distinctive nutritional requirements associated with the management of diabetes mellitus (DM), the agency states:

There are no distinctive nutritional requirements associated with the management of DM. Essential nutrient requirements for individuals affected by DM are no different than those for unaffected (generally healthy) persons. Following an individualized healthy, well-balanced diet is crucial to managing conditions such as DM. There are nutritional recommendations established for persons to manage DM (Refs. 3, 4, and 5).

Ref. 3, 4, and 5 are publications of American Diabetes Association and Centers for Disease Control and Prevention on the importance of controlling diabetes by managing the regular diet. This example underscores FDA's continued narrow interpretation of the scope of medical foods.

FDA's Recent Warning Letters to Medical Food Companies

FDA issued several Warning Letters following its August 2013 draft guidance. While these letters did not provide further details on FDA's current thinking about what constitutes a medical food, they nonetheless identified additional diseases and conditions that, in FDA's opinion, do not present unique nutritional requirements and are inappropriate for medical food applications. The Warning Letters also illustrate the agency's efforts at maintaining an enforcement presence in the medical foods area. The agency's key findings in these letters are summarized below.

  • Metagenics, Inc. Warning Letter (August 13, 2013)

Metagenics, Inc. manufactured medical foods for various diseases and conditions including chronic fatigue syndrome, fibromyalgia, leaky gut syndrome, metabolic syndrome, cardiovascular disease, inflammatory bowel conditions, inflammatory bowel disease, type II diabetes, atopic disorders, bariatric patients pre-and post-operatively, and peripheral artery disease. FDA found that such products did not meet the statutory definition of a medical food because these products are intended for patients with diseases and conditions that do not present any distinctive nutritional requirements.

  • Accera, Inc. Warning Letter (December 26, 2013)

FDA stated that the product label promoted the Axona® product for the "management of the metabolic processes associated with mild to moderate Alzheimer's disease." However, the agency was not aware of any distinctive nutritional requirements or unique nutrient needs for individuals with mild to moderate Alzheimer's disease. As such, FDA concluded the product was not a medical food as the term is defined in the statute.

  • NVN Therapeutics Warning Letter (December 26, 2013)

FDA reasoned that because there are no distinctive nutritional requirements or unique nutrient needs for individuals with Polycystic Ovary Syndrome, the company's product was not a medical food as the term is defined in the statute.