Academy Comments to FDA re Inborn Errors Dietary Management Clinical Trials

September 24, 2018

Dockets Management Staff (HFA-305)
Food and Drug Administration
5630 Fishers Lane
Rm. 1061
Rockville, MD 20852

Re: Draft Guidance: Inborn Errors of Metabolism That Use Dietary Management: Considerations for Optimizing and Standardizing Diet in Clinical Trials for Drug Product Development

Dear FDA Dockets Management Staff:

The Academy of Nutrition and Dietetics (the "Academy") appreciates the opportunity to submit comments to the Food and Drug Administration (FDA) at the United States Department of Health and Human Services (HHS) related to its July 24, 2018 draft guidance "Inborn Errors of Metabolism That Use Dietary Management: Considerations for Optimizing and Standardizing Diet in Clinical Trials for Drug Product Development." Representing more than 104,000 registered dietitian nutritionists (RDNs),1 nutrition and dietetic technicians, registered (NDTRs), and advanced-degree nutritionists, the Academy is the largest association of nutrition and dietetic professionals in the United States. RDNs provide professional services across numerous settings, including nutrition therapies to patients with special health care needs in clinical and community contexts.

The Academy generally supports this draft guidance and makes suggestions below to enhance clarity and utility.

A. Recommendations

The draft guidance identifies issues with current research approaches and provides some guidance to reduce some of the diet-related variability. Due to enhanced screening methods and technologies, the number of diagnosable inborn errors of metabolism (IEM) continues to steadily increase.2 Research to define optimal treatment methods is essential to providing optimal quality of life for these patients. Accordingly, the Academy offers the following suggested enhancements for the draft guidance.

  1. For the bullet point that starts on line 110, the general concept is valid, but FDA and researchers may want to consider starting from the expectation there will be exceptions, especially when a trial is investigating a therapy that would likely be used in conjunction with or to augment dietary management.
  2. While planned procedures were addressed, acute illness was not addressed. Additionally, ensuring a plan is in place for "sick days" would also be beneficial.
  3. We also suggest that research define what an "optimal and stable diet" is for the subject IEM.
  4. For line item 150, we suggest modifying: "measure" to "tool."
  5. For Section III A or C (considerations for optimizing diet), we suggest the following addition: "To ensure consistency, participants should use standardized household measurements or otherwise designated measuring devices for estimating amounts of food whenever possible."

B. Conclusion

The Academy appreciates the opportunity to comment on the proposed information collection for the "Inborn Errors of Metabolism That Use Dietary Management: Considerations for Optimizing and Standardizing Diet in Clinical Trials for Drug Product Development" docket. Please contact either Jeanne Blankenship at 312-899-1730 or by email at jblankenship@eatright.org or Mark Rifkin at 202-775-8277 ext. 6011 or by email at mrifkin@eatright.org with any questions or requests for additional information.

Sincerely,

Jeanne Blankenship, MS, RDN
Vice President
Policy Initiatives and Advocacy
Academy of Nutrition and Dietetics

Mark E. Rifkin, MS, RD, LDN
Manager
Consumer Protection and Regulation
Academy of Nutrition and Dietetics


1 The Academy approved the optional use of the credential "registered dietitian nutritionist (RDN)" by "registered dietitians (RDs)" to more accurately convey who they are and what they do as the nation's food and nutrition experts. The RD and RDN credentials have identical meanings and legal trademark definitions.

2 Deodato F, et al. Inborn errors of metabolism: an update on epidemiology and on neonatal-onset hyperammonemia. Acta Paediatr Suppl. 2004 May;93(445):18-21.