Efficacy and Safety of Janus Kinase Inhibitors in Patients with Vitiligo: A Systematic Review and Meta‐Analysis

Although several case reports and small clinical trials have reported promising outcomes with Janus kinase (JAK) inhibitors for vitiligo, high-quality evidence and guidelines are lacking. We evaluated the efficacy and safety of JAK inhibitors for the treatment of vitiligo using a meta-analysis of randomized controlled trials (RCTs). We searched the PubMed, Embase, and Cochrane Library databases up to August 2023, with additional studies from ClinicalTrials.gov and company websites. We assessed outcomes, including percentage improvement in total vitiligo area score index (TVASI) and facial vitiligo area score index (FVASI); the proportion of patients achieving 50% improvement in TVASI (TVASI50) and 50% and 75% improvement in FVASI (FVASI50 and FVASI75); the risk of treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), infections, and skin-related adverse events (AEs). Five studies with 1,550 participants were included. JAK inhibitors were associated with a higher proportion of TVASI50 (relative risk [RR] 2.67, 95% confidence interval [CI] 1.24-5.78) and FVASI75 (RR 3.97, 95%CI 2.62-6.02) responders than placebo. JAK inhibitors significantly increased the risk of skin-related AEs (RR 1.96, 95% CI 1.29-2.98) compared with placebo. However, the risk of TEAEs, SAEs, and infections was not significantly different between the JAK inhibitor and placebo groups. Subgroup analysis showed that JAK1 and JAK1/2 inhibitors were more effective than JAK3 inhibitors. However, there was insufficient evidence to suggest that the route of administration affects the efficacy and safety of JAK inhibitors in vitiligo. These findings indicate that JAK inhibitors are effective in repigmentation and well tolerated in patients with vitiligo.