Review
This review examines the rationale and emerging evidence for combining Thymosin α1 (Tα1) — a naturally occurring, pleiotropic immunomodulatory peptide — with immune checkpoint inhibitors (ICIs) in the treatment of solid tumors. The authors first outline the biological characteristics of Tα1, highlighting its dual role in enhancing immune competence (e.g., promoting T-cell maturation and activation) while simultaneously regulating excessive immune responses. They then synthesize preclinical and clinical evidence suggesting that Tα1 may address key limitations of ICI monotherapy, including tumor heterogeneity, immunosuppressive tumor microenvironments, and immune-related adverse events (irAEs). The review argues that Tα1 can synergistically remodel the tumor immune microenvironment when combined with ICIs, potentially improving overall response rates. Preliminary clinical findings cited in the review indicate promising efficacy and manageable safety profiles for the combination. The authors acknowledge that the current evidence base relies heavily on early-phase or smaller studies and explicitly call for large-scale, long-term clinical trials to validate sustained benefits. As a narrative review, it does not generate new primary data, and conclusions are limited by the quality and scale of the underlying studies reviewed.
Frontiers in immunology · May 2026DOI ↗ Review
This review paper examines the relationship between aging and Thymosin Alpha-1 (Tα1), a peptide hormone naturally produced by the thymus gland. The authors describe how age-related thymic involution leads to reduced T-cell production, chronic low-grade inflammation (inflammaging), and heightened vulnerability to age-related diseases — a phenomenon collectively termed immunosenescence. The paper outlines Tα1's proposed mechanisms of action, including stimulation of T-cell differentiation, enhancement of thymic output, and modulation of dendritic cells and macrophages. It also highlights Tα1's immunomodulatory, anti-inflammatory, and antioxidant properties. The authors review preclinical and clinical evidence suggesting Tα1 may improve vaccine responses in elderly populations and help counteract immunosenescence. Additionally, the paper discusses Refnot, a hybrid fusion drug combining Tα1 with tumor necrosis factor alpha (TNFα), which reportedly retains antitumor activity while exhibiting reduced toxicity compared to TNFα alone. The authors conclude that Tα1 holds therapeutic promise for age-related immune dysfunction but emphasize that long-term efficacy and safety data in geriatric populations remain limited and that further research is warranted. As a review, this paper synthesizes existing literature rather than presenting original experimental data.
International journal of molecular sciences · Nov 2025DOI ↗ Review
This review article explores phenotypic drug discovery (PDD) as a research framework and uses thymosin alpha-1 (Tα1), a thymic peptide hormone, as a central case study. PDD is described as an approach that screens compounds based on observable effects in cells, tissues, or whole organisms, without requiring prior knowledge of a specific molecular target. The authors contrast PDD with target-based drug discovery and argue that because disease definitions are largely symptom-based, therapeutic development can benefit from a phenotypic lens. The paper discusses how Tα1 has been evaluated in both preclinical and clinical settings, highlighting its complex immunomodulatory properties and its involvement in host-microbe metabolic interactions across multiple targets and metabolites. The authors also address challenges inherent to PDD, including hit validation and target deconvolution, and suggest that advances in big data analytics may help overcome these hurdles. The article further argues that Tα1's broad therapeutic utility can be meaningfully situated within the PDD framework and the modern precision medicine era. As a narrative review, it does not present original experimental data, and its conclusions are shaped by the selection and interpretation of existing literature.
Frontiers in medicine · Jun 2024DOI ↗