Longer Topical JAK Inhibitor Treatment Linked to Vitiligo Improvement in Real-World Study

A real-world study of patients with vitiligo found that longer treatment duration with topical Janus kinase (JAK) inhibitors was independently associated with improvement in Vitiligo Area Scoring Index (VASI) scores, highlighting the potential importance of sustained treatment before evaluating response.

The retrospective study, published in JID Innovations, included 120 patients treated at an academic dermatology referral center in Southern California. Investigators sought to evaluate demographic and clinical predictors of response to topical JAK inhibitors, use of concurrent narrowband UVB (NB-UVB) phototherapy, and treatment approval in a racially and ethnically diverse cohort.

Evaluating Topical JAK Inhibitors in a Diverse Population

Patients were evaluated between April 2018 and April 2024 and were required to have at least 2 dermatology visits, recorded VASI scores, insurance information, and current or previous topical JAK inhibitor treatment. The cohort was 34.2% Asian, 16.6% Hispanic, and 49.2% White, with a mean age of 42 years and mean treatment duration of 9.67 months.

Vitiligo was classified as generalized in 40% of patients, localized in 37.5%, acrofacial in 18.3%, and segmental in 4.2%. Investigators defined VASI improvement as any decrease between the first and most recent recorded VASI score.

Longer Treatment Duration Associated With VASI Improvement

On bivariate analysis, longer treatment duration was significantly associated with VASI improvement (P = .010). Patients who improved had received treatment for a mean of 13 months compared with 8 months among those without improvement.

The association remained significant after adjustment for sex, ethnicity, age, Fitzpatrick Skin Type, vitiligo classification, dual therapy, and treatment duration. Each additional month of treatment was associated with an 11% increase in the odds of VASI improvement (adjusted odds ratio [aOR], 1.11; 95% CI, 1.04-1.20; P < .001).

The investigators wrote that the finding reinforces the importance of counseling patients about the time-dependent nature of repigmentation and maintaining treatment long enough to appropriately assess therapeutic response.

Ethnicity Findings Require Careful Interpretation

Ethnicity was also associated with treatment response. Fifty percent of Hispanic patients experienced VASI improvement compared with 27% of non-Hispanic patients on bivariate analysis. After adjustment, non-Hispanic patients had 69% lower odds of improvement compared with Hispanic patients (aOR, 0.307; 95% CI, 0.099-0.912; P = .034).

However, the investigators cautioned against interpreting ethnicity itself as the cause of differing treatment responses. Hispanic patients had a greater proportion of localized vitiligo than other groups, and the relatively small sample leaves open the possibility of residual confounding despite adjustment for vitiligo classification. The authors called for larger population-based studies to better investigate these associations.

Public Insurance Linked to Higher Treatment Denial Rates

The analysis also identified differences in access to topical JAK inhibitor therapy. Publicly insured patients accounted for 60% of prescription denials compared with 40% among privately insured patients (P = .018).

The authors noted that this disparity had not previously been reported in vitiligo and suggested that insurance barriers could compound existing gaps in access to treatment.

Findings Support Need for Longer-Term, More Diverse Research

The investigators acknowledged several limitations, including the single-center retrospective design, the relatively small cohort, limited representation of Black patients and other groups, and small numbers in several Fitzpatrick Skin Type categories. Additionally, VASI improvement was defined as any reduction in score, meaning the analysis did not measure the magnitude or clinical significance of repigmentation.

The authors concluded that the findings provide an initial real-world look at variation in topical JAK inhibitor response while highlighting disparities in treatment access. They called for larger multicenter studies incorporating more underrepresented populations, standardized VASI assessment, objective pigmentation measurements, and social determinants of health data.

References

1. Rizwi H, Nguyen BT, Chahine A, Dahdoul T, Shiu J. Demographic factors associated with response to topical Jak inhibitors in a diverse vitiligo cohort. JID Innovations. 2026;6:100520. doi:10.1016/j.xjidi.2026.100520. https://pubmed.ncbi.nlm.nih.gov/42733611/
2. Rosmarin D, Passeron T, Pandya AG, et al. Two phase 3, randomized, controlled trials of ruxolitinib cream for vitiligo. N Engl J Med. 2022;387:1445-1455 https://pubmed.ncbi.nlm.nih.gov/36260792/