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2003-2004
President
Clark T. Sawin, M.D.
Washington, D.C.
Secretary
Gregory A. Brent, M.D.
Los Angeles, California
Treasurer
Charles H. Emerson, M.D.
Worcester, Massachusetts
President-Elect
Paul W. Ladenson, M.D.
Baltimore, Maryland
Directors
Peter A. Singer, M.D.
Los Angeles, California
Jeffrey R. Garber, M.D.
Boston, Massachusetts
Stephanie L. Lee, M.D., Ph.D.
Boston, Massachusetts
John C. Morris, III, M.D.
Rochester, Minnesota
Rebecca S. Bahn, M.D.
Rochester, Minnesota
Donald L. St. Germain, M.D.
Lebanon, New Hampshire
Steven I. Sherman, M.D.
Houston, Texas
Bryan R. Haugen, M.D.
Denver, Colorado
Sandra M. McLachlan, Ph.D.
Los Angeles, California
Executive Director
Barbara R. Smith, CAE
Headquarters Office
American Thyroid Association
6066 Leesburg Pike, Suite 550
Falls Church, Virginia 22041
Phone: 703 998-8890
Fax:: 703 998-8893
E-mail: bsmith@thyroid.org
Web: www.thyroid.org
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October 1, 2003
Janet Woodcock, M.D.
Director, Center for Drug Evaluation and Research
Food and Drug Administration
5600 Fishers Lane, HFD-240
Rockville, MD 20857
Dear Dr. Woodcock:
I am
writing on behalf of Dr. Peter Singer, Immediate Past President
of the American Thyroid Association; Dr. E. Chester Ridgway, President
of the Endocrine Society; and Dr. Donald Bergman, President of the
American Association of Clinical Endocrinologists. We thank you
for the thoughtful manner in which you and your staff recently listened
to the concerns of our societies, physician members, and patients
regarding dose precision and bioequivalence standards for levothyroxine
sodium formulations.
We are
heartened by the commitment that you made to plan and hold a workshop
of sufficient depth and duration to address all of the relevant
issues: bioequivalence testing baseline correction, optimal test
subjects, and acceptable confidence limits; and TSH as a pharmacodynamic
measure. We also support your interest in designing a crossover
chronic thyroxine therapy trial with serum TSH as an outcome. We
agree with you that a properly designed and executed study could
address the fundamental concerns that physicians and their patients
have about optimizing the safety and effectiveness of thyroxine
therapy. We offer our assistance in designing, implementing, and
interpreting the results of such a study.
Because
of the concerns that we all share regarding thyroxine dose precision
and limitations in the current bioequivalence standard, we ask that
1) FDA suspend approval of new formulations until these matters
are resolved, and 2) FDA not make a final decision regarding equivalence
testing until it has received further input from experts at the
workshop that you proposed.
As you
requested, we will send to you a draft agenda and list of potential
contributors to the workshop program that you have proposed.
Although
I am no longer Secretary of the American Thyroid Association, I
have become president-elect and our new president, Dr. Clark Sawin,
has asked me to remain the primary point of contact between the
three societies and FDA. We look forward to hearing from you.
Sincerely,
Paul W. Ladenson, M.D.
President-Elect, American Thyroid Association
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