Protocol for a systematic review and meta-analysis on Janus kinase inhibitors in the management of vitiligo
Authors: Pranić Shelly , Pulumati Anika , Vuković Dubravka 
Published: April 2024

Abstract
Background
Vitiligo is a disease that affects people of all skin shades and can impact their quality of life. Reliable evidence on the effectiveness and adverse events associated with the recent use of Janus kinase (JAK) inhibitors to treat vitiligo is needed. This protocol for a systematic review and meta-analysis seeks to collect evidence from both randomized controlled trials (RCTs) and observational studies to determine the effectiveness and patient-centered outcomes concerning treatment with JAK inhibitors.

Methods
We will conduct a systematic review of the literature for RCTs and observational studies that used upadacitinib, ritlecitinib, brepocitinib, ifidancitinib, cerdulatinib, deglocitinib, baricitinib, tofacitinib, and ruxolitinib JAK inhibitors as treatments for vitiligo compared to placebo, no treatment, or combination therapies. We will systematically search from inception in Epistemonikos, MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, EMBASE, ClinicalTrials.gov, PsycINFO, Allied and Complementary Medicine Database, Latin American and Caribbean Health Sciences Literature, Web of Science Core Collection, relevant preprint servers, and the gray literature. Ethics approval was not sought as the protocol and systematic review will not involve human participants, but rather summarized and anonymous data from studies. Primary outcomes include quality of life, percentage repigmentation, decreased vitiligo within 1 year or more, lasting repigmentation after a 2-year follow-up, cosmetic acceptability of repigmentation and tolerability or burden of treatment, and adverse events. Secondary outcomes are patient and study characteristics. We will include full-text articles, preprints, and clinical trial data in any language and all geographic regions. For data sources unavailable in English, we will obtain translations from global collaborators via the Cochrane Engage network. We will exclude articles for which sufficient information cannot be obtained from the authors of articles and systematic reviews. At least two investigators will independently assess articles for inclusion and extract data; reliability will be assessed before subsequent selection and data extraction of remaining studies. The risk of bias and certainty of evidence with Grading of Recommendations Assessment, Development, and Evaluation guidelines will be assessed independently by at least two investigators. We will estimate treatment effects by random-effects meta-analyses and assess heterogeneity using I2. Data that cannot be included in the meta-analysis will be reported narratively using themes.

Discussion
The proposed systematic review and meta-analysis describe the methods for summarizing and synthesizing the evidence on the effectiveness and patient-centered outcomes concerning the treatment of vitiligo with JAK inhibitors that were recently approved for this indication. To disseminate further the results of our systematic review, we plan to present them at international conferences and meetings. Our findings will provide robust evidence to facilitate decision-making at the policy or practitioner level.

Systematic review registration
PROSPERO CRD42023383920.