Real-World Use of Topical Ruxolitinib in Vitiligo: A Retrospective Cross-Sectional Mixed-Methods Infodemiology Study of the r/Vitiligo Subreddit (Preprint)

Vitiligo significantly impairs quality of life. Topical ruxolitinib is a novel Janus kinase inhibitor approved for non-segmental vitiligo, but real-world patient experiences, particularly regarding efficacy, side effects, and access challenges following approval, are not fully captured by clinical trials. Online patient forums like Reddit offer valuable insights into these aspects. To analyse discussions on the r/Vitiligo subreddit regarding topical ruxolitinib to understand real-world patient experiences, perceived treatment success, side effects, access barriers, and overall sentiment. We conducted a retrospective, cross-sectional infodemiology study of posts and comments mentioning ruxolitinib or Opzelura® on r/Vitiligo (January 2022-December 2024) was conducted. After filtering and preprocessing, 2,950 entries were analysed. Computational linguistics (all-MiniLM-L6-v2), including sentence-transformer embeddings for semi-supervised topic classification into Therapy Success, Side Effects, Insurance & Cost plus Off-topic were employed. Valence Aware Dictionary and sEntiment Reasoner (VADER) (-1 to +1) for sentiment analysis was assessed. Temporal trends were analysed, and model performance was validated manually against blinded manual annotation of n=500 entries. Representative qualitative data were reviewed. Discussions increased following regulatory approvals. "Therapy Success" was the largest cluster (1765/2950 entries, 59.8% [95% confidence interval (CI) 58.1-61.6]) with positive sentiment (avg. 0.473 [95% CI 0.46-0.48]), frequently describing facial repigmentation and adjunctive use with phototherapy. Users also reported encouraging hair repigmentation within treated areas and success even on vitiligo spots present for over 20 years, while noting that areas like hands and feet were particularly treatment-resistant. The "Side Effects" cluster (558/2950 entries, 18.9% [95% CI 17.5-20.3]) had negative sentiment (avg. -0.110 [95% CI -0.14-0.07]), frequently mentioning application-site acne but also fatigue and in rare anecdotal reports, more severe events like panic attacks or anemia. The "Insurance & Cost" cluster (491/2950 entries, 16.6% [95% CI 15.3-18.0]) had positive sentiment (avg. 0.349 [95% CI 0.31-0.39]), dominated by discussions on high costs and access difficulties, alongside strategies like co-pay programs but also noting insurance denials that often classified the treatment as cosmetic. Manual model validation showed substantial agreement (Accuracy 88.4% [95% CI 86-91], F1 0.893 [95% CI, 0.865-0.918], Cohen's Kappa 0.801 [95% CI, 0.760-0.840]). Real-world Reddit narratives broadly corroborate clinical trial efficacy signals, particularly facial repigmentation and utility alongside phototherapy, while highlighting practical barriers: frequent application-site acne and cost/insurance friction. These findings have direct clinical and policy implications: clinicians can proactively counsel about expected benefit on facial areas, monitor and manage acne/irritation, and discuss combination with phototherapy; practices and payers can mitigate access delays using prior-authorization templates and co-pay assistance. Social-media infodemiology thus complements pharmacovigilance and health services research by quantifying patient-reported outcomes (~60% success-themed content, mean sentiment 0.473 [95% CI 0.46-0.48]) and surfacing access issues (~17% cost/insurance content) at scale, informing patient counseling and coverage decisions in routine care.