Bempikibart Shows Durable Responses, Post-Dosing Cessation for Severe AA
A novel IL-7/TSLP bifunctional receptor agonist has shown long-term durable responses and post-dosing cessation for patients with severe or very severe alopecia areata, according to a presentation at the 2025 American Academy of Dermatology (AAD) Annual Meeting in Orlando, Florida, by Brett King, MD, PhD, FAAD.
Dr. King presented “Initial Results From the SIGNAL-AA Study: Randomized Placebo Controlled Phase 2a Trial of Bempikibart, a Novel IL-7/TSLP Bifunctional Receptor Antagonist in Patients with Severe or Very Severe Alopecia Areata.”
Patients with Severity of Alopecia Tool (SALT) scores of 50 to 100 experienced a mean SALT score reduction of 16.3% through dosing cessation at 24 weeks of bempikibart treatment, and patients with SALT scores of 50 to 95 experience a mean reduction of 24.5% in that time. Twelve weeks after that dosing cessation, those percentages had increased to 19.9% and 27.8%, respectively.
“We're still seeing a trend toward lower SALT scores after dosing cessation,” Dr. King said.
Additionally among the patients with baseline SALT scores of 50 to 95, the portion who achieved SALT score increases of 30% or more jumped from 26.7% at Week 24 (dosing cessation) to 28.6% at Week 26 and 53.8% at Week 36.
“[That is] a provocative rate,” Dr. King said, “suggesting a continued effect after dosing cessation.”
Dr. King said bempikibart’s mechanism of action could be responsible for long-term durable responses post dosing cessation.
“It is an antibody to the IL-7 receptor alpha subunit, which is a subunit shared by the IL-7 and the TSLP receptors, thereby inhibiting activity of IL-7 and TSLP,” Dr. King said. “There is a favorable [pharmacokinetic profile] and receptor occupancy observed in phase 2 clinical trials, and there are also really provocative clinical biomarkers indicative of appropriate inhibition of IL-7 and TSLP demonstrated in patients. There is a very longstanding [concept] in the scientific literature suggesting a role for IL-7 in modulation of T-cell responses underlying inflammatory disease and autoimmune disease, and it’s thought that IL-7 blockade can lead to T cell homeostasis.”
All treatment-related events were mild or moderate, with no new safety signals.
Dr. King said the next step will be a phase 2b trial with a slightly different study design, including treatment through Week 36.