Novel Small-Molecule Treatment and Emerging Biological Therapy for Psoriasis

Psoriasis is an immune-related disorder that is marked by abnormal thickening of the skin, the rapid multiplication of keratinocytes, and complex interactions between immune cells and the affected areas. Although psoriasis cannot currently be cured, drugs can alleviate symptoms by regulating immune homeostasis and preventing comorbidities. There are many types of drugs to treat psoriasis: small-molecule drugs, including corticosteroids; retinoids; vitamin D analogs; and immunosuppressants, such as glucocorticoid ointment, tretinoin cream, methotrexate tablets, etc. Macromolecular biological drugs, such as Certolizumab, Secukinumab, Guselkumab, etc., include monoclonal antibodies that target various inflammatory signaling pathways. Compared with traditional small-molecule drugs, biological therapies offer better targeting and lower systemic side effects, but their high costs and invasive administration modes constrict their widespread use. Spesolimab is the latest biological agent used to target the interleukin-36 receptor (IL-36R) to be approved for market use, which significantly reduces the risk of general pustular psoriasis (GPP) flare by 84%. Additionally, there are several biological agents used to target the interleukin-23/T helper 17 cell pathway that have already entered Phase II and III clinical trials. At present, the first-line therapeutic strategy for mild psoriasis is topical administration. Systemic therapy and phototherapy are preferred for treating moderate to severe types. However, the current therapeutic drugs for psoriasis cannot completely meet the clinical needs. More advanced drug delivery systems with optimized target effects and better bioavailability are required. Nanocarriers are emerging for the delivery of proteins, nucleic acids, and cell-based therapies. In this review, we analyze the current status of psoriasis therapeutics and discuss novel delivery systems for diverse psoriasis drugs, as well as emerging cell-based therapies. We also summarize the therapeutic effectiveness of different delivery strategies.