Ancuceanu Robert MD, PhD
U.M.Ph. “Carol Davila”, Bucharest
Inhibitors of JAK kinase in the treatment of alopecia areata
Author: Robert Ancuceanu
From the end of 2017 to the present, there has been a growing interest in the use of JAK kinase inhibitors in the treatment of several dermatological conditions, including alopecia. Potential therapeutic benefits of JAK-STAT signalling pathway inhibition have been reported in individual case reports, small case series, open-label clinical trials (on small samples of subjects), and a randomized placebo-controlled study. Inhibitors of JAK kinase already authorized (tofacitinib, baricitinib), as well as inhibitors still unauthorized (PF-06651600, ATI-501 or CTP-543, which is a modified version of ruxolitinib) with various affinities and selectivities for the various JAK kinase subtypes (JAK 1, JAK2, JAK3 or TYK2) are currently being evaluated in clinical trials, primarily in alopecia areata. A Medline computerized query using relevant keywords identified 83 potentially relevant topics. A text mining exercise has identified a much greater interest in efficacy than in safety (for instance, the term “efficacy” occurs 39 times and “effective” 18 times, while the term “safety” is used 21 times, and “safe” only 4 times (i.e. a relative frequency of efficacy and safety terms of about 2: 1). A wordcloud that summarizes the most common terms in the Medline abstracts is presented in Fig. 1. The main medicinal products that have been of interest to date are tofacitinib and ruxolitinib, but considering the ongoing clinical trials, the range of molecules of interest is expected to be broader for both dermatology and rheumatology. The presentation summarizes the biological and immunological bases that explain the use of JAK kinase inhibitors in alopecia areata, the currently available efficacy and safety data, the certainties and uncertainties about this new group of drugs with multiple potential uses in dermatology.