Scalp Hair Regrowth in Alopecia Areata Patients Treated With Baricitinib: Early, Gradual, and Late Responders

The study analyzed data from the BRAVE-AA1 and BRAVE-AA2 trials, where patients with severe alopecia areata (AA) were treated with baricitinib. The researchers identified three subgroups of scalp hair regrowth: early responders (0–12 weeks), gradual responders (12–36 weeks), and late responders (36–52 weeks). Early responders showed faster and greater improvement. Patients with 95% or more scalp hair loss at the start were often gradual or late responders. A higher proportion of patients treated with 4 mg of baricitinib responded compared to those treated with 2 mg. Non-responders after 52 weeks usually had a longer history of AA. The study concluded that the time to first signs of scalp hair regrowth can predict the future trajectory of regrowth and response to baricitinib treatment. Factors such as the duration and severity of hair loss and the baricitinib dose influence the likelihood of response.