Thymosin alpha-1

Updated 19 Oct 2026 · Peptilex evidence grade B (A = approved, large trials · D = mainly animal studies)

Approved in more than 30 countries (Zadaxin). A 2026 meta-analysis of 20 trials linked it to fewer chemotherapy side effects in gastric cancer; a phase 3 trial in 2,500 people after colorectal cancer surgery is under way.

622PubMed papers

374Human studies

39Randomized trials

39Registered studies

11Ongoing / starting

8Phase 3+

Registered trials

From ClinicalTrials.gov, matched by name in the study title.

Study	Phase	Status	Participants	Start
Thymosin Alpha 1 Combined With Anti-PD-1 Monoclonal Antibody in Elderly Patients With Advanced Melanoma NCT07644897 · Sun Yat-sen University	Phase 2	Recruiting	55	2023-05
"Thymalfasin Immunotherapy Study with Triple Regimen in Advanced MSS/pMMR Colorectal Cancer" NCT06829355 · Beijing Friendship Hospital	Phase 2	Recruiting	52	2025-02
Thymalfasin and Recombinant Human IL-2 Injections in Treating Lymphocytopenia for Patients With Malignant Hematological Tumors NCT06584006 · The First Affiliated Hospital of Xiamen University	Phase 2	Recruiting	50	2024-09
Phase II Trial of Neoadjuvant Thymalfasin, PD-1 Inhibitor, and Chemoradiotherapy for cStage III GEJ Adenocarcinoma NCT07277439 · The First Affiliated Hospital with Nanjing Medical University	Phase 2	Recruiting	48	2025-12
Efficacy and Safety of Anti-PD-1, Thymalfasin, and SOX in Neoadjuvant Treatment of cStage III Gastric/Gastroesophageal Junction Adenocarcinoma NCT06461910 · Zekuan Xu	Phase 2	Recruiting	30	2024-06
Neoadjuvant Chemoradiotherapy Combined With PD-1 Inhibitor and Thymalfasin for pMMR/MSS Locally Advanced Mid-low Rectal Cancer NCT06056804 · Beijing Friendship Hospital	Phase 2	Running	20	2024-01
Thymalfasin (Thymosin Alpha 1; Ta1) as an Enhancer of Vaccine Response Among Older Adults Receiving Booster Doses of COVID-19 Vaccine NCT06821100 · The Methodist Hospital Research Institute	Phase 1	Recruiting	75	2024-12
Protective Effect of Ulinastatin and Thymosin α1 Against Negative Immune Dysregulation and Organ Dysfunction After Acute Aortic Dissection Surgery (PANDA XI) NCT06966687 · Nanjing Medical University	–	Enrolling	200	2025-04
Thymalfasin for Immune Recovery in Adults With Sepsis NCT07866118 · Shanghai Zhongshan Hospital	–	Recruiting	60	2026-10
Study of Adebrelimab Combined With Thymalfasin and Chemotherapy for Neoadjuvant Treatment of Esophageal Cancer NCT07780721 · The Affiliated Hospital of Putian University	Phase 2	Starting soon	31	2026-08
Radiotherapy With Sequential Chemotherapy Combined With PD-1 Inhibitor and Thymalfasin for BRPC NCT06573398 · Ruijin Hospital	Phase 2	Starting soon	20	2024-09
Thymosin Alpha 1 in the Prevention of Pancreatic Infection Following Acute Necrotizing Pancreatitis NCT02473406 · Weiqin Li	Phase 4	Completed	508	2018-03
Efficacy Study of Thymosin alpha1 & Pegylated Interferon-alpha2a to Treat Chronic Hepatitis B NCT00291616 · Seoul National University Hospital	Phase 4	Completed	52	2005-12
Efficacy of Thymosin Alpha 1 on Improving Monocyte Function for Sepsis NCT02883595 · Sun Yat-sen University	Phase 4	Completed	20	2016-03
Thymosin Alpha-1 in Combination With Peg-Interferon Alfa- 2a and Ribavirin for the Therapy of Chronic Hepatitis C Nonresponsive to the Combination of IFN and Ribavirin. NCT01178996 · sigma-tau i.f.r. S.p.A.	Phase 3	Completed	552	2004-12
Thymosin Alpha 1, Interferon Alpha, or Both, in Combination With Dacarbazine in Patients With Malignant Melanoma NCT00911443 · sigma-tau i.f.r. S.p.A.	Phase 2	Completed	488	2002-07
Thymosin Alpha 1 to Prevent COVID-19 Infection in Renal Dialysis Patients NCT04428008 · William B. Ershler, MD	Phase 2	Completed	189	2021-01
A Pilot Study to Evaluate ZADAXIN's® (Thymalfasin) Ability to Enhance Immune Response to the H1N1sw Influenza Vaccine NCT01031966 · sigma-tau i.f.r. S.p.A.	Phase 2	Completed	120	2009-11
Phase II Trial for Combination Treatment of PEG-Tα1 and Adefovir for HBeAg Positive Chronic Hepatitis B NCT02366208 · Jiangsu Hansoh Pharmaceutical Co., Ltd.	Phase 2	Completed	116	2011-05
The Impact of Thymosin α-1 on the Efficacy of Concurrent Chemoradiotherapy Followed by Immunotherpay Consolidation for Locally Advanced NSCLC NCT06139419 · Sun Yat-sen University	Phase 2	Completed	114	2023-07
Study of Thymosin α1 to Reduce Acute Pneumonia For Bulky None-small Cell Lung Cancer NCT03659578 · Sun Yat-sen University	Phase 2	Completed	69	2018-08
A Trial of Thymalfasin in Adult Patients With Hepatocellular Carcinoma NCT00082082 · SciClone Pharmaceuticals	Phase 2	Completed	–
Zadaxin and HIV-positive Patients With Immune Reconstitution Disorder NCT04963712 · Shanghai Public Health Clinical Center	Early phase 1	Completed	20	2021-09
Protective Effect of Thymosin α1 Against Negative Immune Dysregulation and Organ Dysfunction After Acute Aortic Dissection Surgery (PANDA II) NCT05339529 · Nanjing Medical University	–	Completed	600	2022-07
Efficacy of Thymosin alpha1 for Severe Sepsis NCT00711620 · Sun Yat-sen University	–	Completed	366	2008-05

Showing 25 of 39 matching registered studies (ongoing first). See all on ClinicalTrials.gov.

Latest randomized trials & key papers

From PubMed. The full story – mechanism, all results, risks – is in the Thymosin profile of the book.

2026Efficacy and safety of thymosin α1 combined with chemotherapy for gastric cancer: a systematic review and meta-analysis of randomized controlled trials
Wang Z et al. · Frontiers in immunology · PMID 42827862
2025Thymosin alpha 1 alleviates inflammation and prevents infection in patients with severe acute pancreatitis through immune regulation: a systematic review and meta-analysis
Tian Y et al. · Frontiers in immunology · PMID 40599771
2024A Prospective and Randomized Control Study on Effects of Thymalfasin for Injection on Perioperative Immune Function and Long-term Prognosis of Patients with Colorectal Cancer
Niu W et al. · Biotechnology & genetic engineering reviews · PMID 37248723
2024Thymosin Alpha 1 Plus Routine Treatment for the Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis
Cao A et al. · Journal of the College of Physicians and Surgeons--Pakistan : JCPSP · PMID 39648386
2024Comprehensive Review of the Safety and Efficacy of Thymosin Alpha 1 in Human Clinical Trials
Dinetz E et al. · Alternative therapies in health and medicine · PMID 38308608
2023A pilot trial of Thymalfasin (Ta1) to prevent covid-19 infection and morbidities in renal dialysis patients: Preliminary report
Tuthill CW et al. · International immunopharmacology · PMID 36881981
2023The efficacy of thymosin alpha-1 therapy in moderate to critical COVID-19 patients: a systematic review, meta-analysis, and meta-regression
Soeroto AY et al. · Inflammopharmacology · PMID 37845598
2022Immune enhancement in patients with predicted severe acute necrotising pancreatitis: a multicentre double-blind randomised controlled trial
Ke L et al. · Intensive care medicine · PMID 35713670

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