Summary
Clinical studies have shown that treatment with thymosin alpha 1 increases response to vaccination, providing up to six times
the typical response seen. In these studies, thymosin alpha 1 was provided as a dose of about 1.6 mg/kg (0.9 mg/m2), injected twice-weekly after vaccination. Future studies will evaluate higher doses, which could allow for a shorter course
of administration.
Thymosin alpha 1 is one of only a few immunomodulating compounds that have been approved for human use and does not appear
to induce any of the side effects and toxicities commonly associated with agents in this class, such as interferon and interleukin-2.
Thymosin has shown great utility in subjects older than 80 years of age, and was even used safely in patients as old as 101
years. Taken together, these data support the use of treatment with thymosin alpha 1 to increase response to vaccination.
Cynthia W. Tuthill is senior vice president and chief scientific officer at SciClone Pharmaceuticals, Inc., Foster City, CA, 650.358.3450, ctuthill@sciclone.com
Stefan Gravenstein is professor of medicine, Brown University and clinical director, quality improvement, at Quality Partners, Providence, RI,
and William B. Ershler is deputy clinical director, clinical research branch, intramural research program, National Institute of Aging, National
Institutes of Health, Baltimore, MD, and director at the Institute for Advanced Studies in Geriatric Medicine, Gaithersburg,
MD.
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