Thymosin Alpha-1

Thymosin Alpha-1 is a 28-amino acid peptide originally isolated from thymus tissue. It has been approved in over 30 countries (though not in the US) for hepatitis B and C treatment, as an immune adjuvant, and for various immunodeficiency conditions. It works by modulating immune cell activity and cytokine production.

PubMed results: 575 · Human studies: 344 · Animal studies: 529

Ranges reflect protocols studied in published research and animal-model extrapolation. Presented for research purposes only, not a recommendation or instruction for human use.

Based on approved indications outside US

• Subcutaneous Injection — standard range 1.6 mg, Twice weekly. 6 months (hepatitis)

2 hours (high confidence)

• Immune modulation (Human clinical data): Demonstrated effects on T-cell function and cytokine balance

• Injection site reactions — Mild, Common. Subcutaneous thymosin alpha-1 administration is generally well tolerated; local injection-site pain, erythema, or discomfort are among the more frequently noted reactions in clinical use outside the US.
• Flu-like symptoms — Mild, Uncommon. Transient fever, fatigue, or flu-like malaise have been reported in some clinical and post-marketing contexts, consistent with immunomodulatory cytokine effects.
• Overall favorable tolerability profile — Mild, Not established. Across hepatitis and immunodeficiency research programs, serious drug-related adverse events have been relatively uncommon, though formal US labeling and large controlled safety databases differ by jurisdiction.

• Hypersensitivity to thymosin alpha-1 (Established): Known hypersensitivity to the peptide or formulation components is a standard exclusion for parenteral immunomodulatory peptides.
• Active autoimmune disease (caution) (Theoretical / Preclinical): Because thymosin alpha-1 modulates T-cell activity and cytokine production, theoretical concern exists about exacerbating autoimmunity; clinical protocols often exclude or carefully evaluate active autoimmune conditions.

Lyophilized (powder): Refrigerated (2-8°C), Up to 24 months. Light sensitive: yes, store dark

Reconstituted (solution): Refrigerated (2-8°C), 4-6 weeks. Solvent: Bacteriostatic water

• NCT07277439 — Phase II Trial of Neoadjuvant Thymalfasin, PD-1 Inhibitor, and Chemoradiotherapy for cStage III GEJ Adenocarcinoma (PHASE2), status: RECRUITING. Indications: Gastric Cancer
• NCT07382375 — AI-assisted Subtyping-directed Precision Treatment in Acute Aortic Dissection (NA), status: NOT_YET_RECRUITING. Indications: Aortic Aneurysm and Dissection
• NCT06139419 — The Impact of Thymosin α-1 on the Efficacy of Concurrent Chemoradiotherapy Followed by Immunotherpay Consolidation for Locally Advanced NSCLC (PHASE2), status: ACTIVE_NOT_RECRUITING. Indications: Non-small Cell Lung Cancer
• NCT02883595 — Efficacy of Thymosin Alpha 1 on Improving Monocyte Function for Sepsis (PHASE4), status: COMPLETED. Indications: Sepsis
• NCT04524169 — Immunotherapy for Elderly Patients With Chronic Osteoporotic Pain (PHASE4), status: UNKNOWN. Indications: Osteoporotic Pain
• NCT00040027 — Thymosin Plus PEG-Interferon in Non-Cirrhotic Hepatitis C Patients Who Did Not Respond to Interferon or Interferon Plus Ribavirin (PHASE3), status: COMPLETED. Indications: Hepatitis C, Hepatitis C, Chronic
• NCT06552598 — The Safety, Tolerability, and Efficacy of KD01 in Gynecologic Malignancies (PHASE1), status: RECRUITING. Indications: Cervical Cancer, Gynecologic Malignancies, Endometrial Cancer
• NCT02535988 — Abscopal Effect for Metastatic Colorectal Cancer (PHASE2), status: WITHDRAWN. Indications: Colorectal Cancer, Metastatic Colorectal Cancer, Thymalfasin
• NCT06178146 — Thymosin Alpha-1 for irAE Secondary to ICIs (PHASE4), status: UNKNOWN. Indications: IrAE
• NCT06461910 — Efficacy and Safety of Anti-PD-1, Thymalfasin, and SOX in Neoadjuvant Treatment of cStage III Gastric/Gastroesophageal Junction Adenocarcinoma (PHASE2), status: RECRUITING. Indications: Gastric Cancer, Esophagogastric Junction Adenocarcinoma
• NCT03659578 — Study of Thymosin α1 to Reduce Acute Pneumonia For Bulky None-small Cell Lung Cancer (PHASE2), status: COMPLETED. Indications: Non-small Cell Lung Cancer
• NCT06584006 — Thymalfasin and Recombinant Human IL-2 Injections in Treating Lymphocytopenia for Patients With Malignant Hematological Tumors (PHASE2), status: RECRUITING. Indications: Hematological Malignancy, Lymphocytopenia
• NCT02867267 — The Efficacy and Safety of Ta1 for Sepsis (PHASE3), status: COMPLETED. Indications: Sepsis
• NCT01178996 — 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. (PHASE3), status: COMPLETED. Indications: Chronic Hepatitis C
• NCT06573398 — Radiotherapy With Sequential Chemotherapy Combined With PD-1 Inhibitor and Thymalfasin for BRPC (PHASE2), status: NOT_YET_RECRUITING. Indications: Carcinoma, Pancreatic Ductal
• NCT05086614 — Thymosin-alpha 1 for Adjuvant Treatment After Radical Resection of High-risk Stage II and III Colorectal Cancer (PHASE3), status: RECRUITING. Indications: Stage II Colorectal Cancer, Stage III Colorectal Cancer
• NCT01943617 — Optimized Treatment and Regression of HBV-induced Compensated Liver Cirrhosis (PHASE4), status: COMPLETED. Indications: Liver Cirrhosis
• NCT00197860 — Dendritic Cell Based Therapy of Renal Cell Carcinoma (PHASE1 / PHASE2), status: COMPLETED. Indications: Advanced Renal Cell Carcinoma
• NCT00711620 — Efficacy of Thymosin alpha1 for Severe Sepsis (NA), status: COMPLETED. Indications: Severe Sepsis
• NCT07103395 — A Study Evaluating Neoadjuvant Chemotherapy, Concurrent Chemoradiotherapy Combined With Dual Immune Checkpoint Blockade in Patients With Locally Advanced Non-Small Cell Lung Cancer (PHASE2), status: RECRUITING. Indications: Lung Cancer (NSCLC)

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