Jak inhibitor intraclass switch in alopecia areata patients: A retrospective review of cases at an academic center

Summary: Abstract Body: Alopecia Areata (AA) is an inflammatory skin condition leading to non-scarring hair loss on the scalp or other hair-bearing areas. Jak inhibitors (JAKi) are used to promote hair growth by blocking the JAK-STAT pathway and down-regulating the inflammatory response. Baricitinib and Ritlecitinib are JAKi approved for the treatment of AA. While there is no significant difference in efficacy between both drugs, there is no data on the switch from one JAKi to another for AA. We analyzed the charts of 16 AA patients at our large academic dermatology clinic between June-2018 and August-2024 for patients prescribed baricitinib and ritlecitinib sequentially. All patients (n=16) were switched from baricitinib to ritlecitinib. On average, patients were on Baricitinib for 414.6 days prior to switch. 6 patients were switched due to primary non-response, while the other 10 were switched after reaching a treatment plateau. The average baseline SALT scores were 81%, with half (n=8) having a score above 95%. The average pre-switch SALT scores were 65%. At the post-switch most recent follow-up visit (average 271 days after switch) SALT scores averaged 52%, with a 20% decrease compared to pre-switch scores and 36% decrease compared to baseline scores. Paired t-tests for difference in SALT scores showed a significant decrease in post-switch scores compared to pre-switch and baseline scores (p<0.01). 2 adverse events were noted, one patient developed mild acne on Baricitinib and continues JAKi therapy. The second experienced decreased leukocyte and platelet counts on Ritlecitinib, leading to its discontinuation. While treatment of AA can be challenging, JAKi offer a unique and effective approach for helping patients with hair regrowth. In our cohort, most patients had reached a treatment plateau and following intraclass switch were able to obtain significant improvement in SALT scores. This study is limited by its small sample-size and retrospective nature; however, we have shown positive results in hair growth after intraclass switch. Isabel C. Silva¹, Saakshi Khattri¹ 1. Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, United States. Clinical Research: Epidemiology and Observational Research