From Legacy to Innovation: Pidotimod's Expanding Therapeutic Horizon.

Pidotimod, a synthetic dipeptide, has been utilized for over three decades as an immunomodulatory agent to prevent recurrent respiratory infections, particularly in immunocompromised populations such as children and the elderly. Originally developed for its ability to enhance innate and adaptive immune responses, pidotimod is now being revisited in light of new clinical insights and emerging therapeutic needs. Recent studies have expanded its potential beyond traditional indications, with evidence supporting its role in patients with chronic respiratory diseases, such as chronic obstructive pulmonary disease (COPD), allergic rhinitis, and even viral infections, including SARS-CoV-2. Pidotimod exerts its effects by stimulating dendritic cells, enhancing toll-like receptor (TLR) expression, and promoting cytokine production, including IL-2 and IFN-γ, thereby supporting both cellular and humoral immunity. This broad-spectrum immune modulation makes pidotimod a promising adjunct in managing immune-mediated diseases and infections in both immunocompetent and immunocompromised individuals. In this review, we examine pidotimod's pharmacodynamics, summarize clinical evidence from recent studies, and explore its evolving role in modern therapeutic strategies for infectious diseases. Given its safety profile and oral administration, pidotimod holds significant promise not only for preventing infections but also as part of a broader immunomodulatory approach in complex disease management.