FDA Bioequivalence Workshop Plans continue with ATA, Endocrine Society and AACE leaders

Steven Galson, M.D., M.P.H.
Acting Director, Center for Drug Evaluation and Research
Food and Drug Administration
5600 Fishers Lane, HFD-240
Rockville, MD 20857

Dear Dr. Galson:

I am writing on behalf of the American Thyroid Association,
the Endocrine Society, and the American Association of Clinical Endocrinologists to follow-up on your November 5 invitation to draft an agenda and propose a list of participants for a workshop addressing issues regarding dose precision and bioequivalence standards for levothyroxine sodium formulations.

Our societies were very encouraged by the commitment that Dr. Woodcock made at our September 15 meeting, and by your subsequent invitation to propose an agenda for a workshop of sufficient depth and duration to address all of the relevant issues. These include bioequivalence testing baseline correction, optimal test subjects, and acceptable confidence limits, and TSH as a pharmacodynamic measure. We propose covering all of these matters, as well as considerations in design of a crossover chronic thyroxine therapy trial with serum TSH as an outcome, in the enclosed draft agenda.

We welcome FDA's review of this proposal and your comments regarding the format, schedule, content, and potential presenters for this meeting. Please note that none of the individuals tentatively designated in this draft have yet been contacted. We look forward to collaborating with you to define the final form and content of the workshop program.

Anne Henig in your office informed Dr. Brent that your staff would be meeting to discuss this matter in early January. I look forward to hearing from you or her soon thereafter.

Sincerely,

Paul W. Ladenson, M.D.
President-Elect, American Thyroid Association

PWL:sr
Enclosure