Advances in Janus Kinase Inhibitors for Vitiligo Treatment

Vitiligo is a cutaneous autoimmune disease characterized by the destruction of epidermal melanocytes leading to white patches with a global prevalence of about 0.5-2%, and patients' quality of life are greatly affected by the change in appearance and social discrimination caused by the disease. Most of the key cytokines in the pathogenesis of vitiligo act through the Janus kinase/signal transducer and activator of transcription signaling pathway, which is an effective therapeutic target. The first generation Janus kinase inhibitors, i.e., tofacitinib and ruxolitinib, inhibit a variety of Janus kinases, whereas the new generation Janus kinase inhibitors, such as ritlecitinib and upadacitinib, exhibit inhibitory effects only on specific Janus kinases; they are therefore selective as well as safer and more effective. In this review, we aim to provide an up-to-date view of vitiligo pathogenesis at the cellular, molecular, and genetic levels and further to elucidate the relationship between Janus kinase/signal transducer and activator of transcription signaling pathway components and vitiligo. Finally, we summarize currently market-approved and preclinical Janus kinase inhibitors, highlighting the latest advances in their clinical applications.