The efficacy and safety of thymosin α1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial
Wu J, Pei F, Zhou L, Li W, Sun R, Li Y, et al.. BMJ. 2025; 388:e082583.
PubMed 39814420 · PMC11780596 · doi:10.1136/bmj-2024-082583
Compares people who got the treatment with people who did not.
Where this design sits
- Cells in a dish
- Animals
- Small human report
- Controlled human trial (this study)
- Pooled analysis
- Who or what was studied
- 1,106 adults with sepsis at 22 centres in China (1,089 analysed)
- Design
- Randomised, double-blind, placebo-controlled phase 3 trial
- Dose
- Subcutaneous injection every 12 hours (dose not given in the abstract)
- Duration
- Up to 7 days of treatment; outcome counted at 28 days
What it found
Thymosin alpha-1 did not lower deaths from sepsis. Within 28 days, 23.4% of the treated group and 24.1% of the placebo group had died (hazard ratio 0.99; 95% CI 0.77 to 1.27). No secondary or safety outcome differed between groups. Two planned subgroup comparisons hinted at different effects by age and by diabetes, and the authors conclude there is no clear evidence that the peptide reduces 28-day mortality in adults with sepsis.
What it doesn’t show
A large, well-controlled trial, but it tested hospital-grade injections in critically ill adults, so it says nothing about the oral or over-the-counter products sold for immune support. The subgroup differences (younger versus older patients, with versus without diabetes) are exploratory and should not be read as a finding that it works in either group. It was run in China only.
Funding and conflicts of interest
The authors declare support from Sun Yat-sen University and Guangdong research programmes and from SciClone Pharmaceuticals; several authors report grants or consultancy fees from SciClone.
Summary written from the study's abstract and checked against PubMed on November 10, 2026. How we check studies. Educational information, not medical advice.
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