Thymosin Alpha 1 (Zadaxin)
Overview
A 28-amino acid peptide originally isolated from thymic tissue (thymosin fraction 5) that serves as a potent immunomodulator. Thymosin alpha 1 enhances T-cell maturation, dendritic cell function, and antibody responses by activating Toll-like receptors (TLR2, TLR9) on innate immune cells. It promotes Th1 immune responses and augments vaccine efficacy while modulating inflammatory cytokine production.
Key Research Findings
Approved in over 35 countries (not FDA-approved) for hepatitis B, hepatitis C, and as an immune adjuvant. Clinical trials showed improved virologic response rates in chronic hepatitis B when combined with interferon. Used during COVID-19 pandemic based on observational data suggesting reduced mortality in critically ill patients (Wu et al., Clin Infect Dis, 2020). Phase 3 trials for hepatocellular carcinoma adjuvant therapy showed trends toward improved survival.
Subcutaneous injection
Investigational
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