Targeted Immunomodulation in Psoriasis: Emerging progress on biologics and small molecules

Psoriasis is a chronic immune-mediated inflammatory skin disorder that affects more than 125 million people worldwide. A dysregulation in the multiple immune signaling pathways involving innate and adaptive immune cells, leads to persistent inflammation and epidermal hyperproliferation in psoriasis. Hyperactivation of immune cells results in excessive production of pro-inflammatory cytokines, including interleukins and tumor necrosis factor-α (TNF-α), alongside increased secretion of antimicrobial peptides by keratinocytes and innate immune cells. This review examines the cytokine-driven immunopathology of psoriasis and recent advances in targeted therapies. Current therapeutic strategies focusing on selective modulation of these pathways through biologic and small molecules are highlighted. Major advances on inhibitors targeting IL-17, IL-23, and JAK/TYK2 signaling pathways are also discussed. Emerging therapies such as sphingosine-1-phosphate (S1P) receptor modulators, RORγt inhibitors, and aryl hydrocarbon receptor (AhR) agonists have also demonstrated promising efficacy and safety, with significant improvements in psoriasis area and severity index (PASI) scores. A deeper understanding of psoriasis immunopathogenesis can transform treatment approaches from broad immunosuppression to precision-targeted therapies. Continued development of cytokine- and signaling pathway-specific agents is expected to improve long-term disease control, safety, and personalized patient outcomes.