Two phase 3 trials of the JAK inhibitor upadacitinib produced substantial scalp hair regrowth in roughly half of patients with severe alopecia areata. Published in JAMA Dermatology, the results showed that 55 percent of patients on the higher dose in one trial and 54.3 percent in the other reached at least 80 percent scalp coverage at 24 weeks.
Those figures sit at the upper end of what has been reported for this class, but the comparison has to be made carefully. In their own pivotal trials, the approved oral JAK inhibitors reported response rates on the same measure ranging from roughly 23 percent to 39 percent, and those trials used different time points, different populations, and different comparators. None was run head-to-head against upadacitinib.
