A Phase 2a Proof-of-Concept Trial of Bempikibart (ADX-914) for the Treatment of Severe Alopecia Areata (SIGNAL-AA)

Part A is a Phase IIa, Randomized, Double-blind, Placebo-controlled, multi-center Proof-of-Concept (POC) study in adult subjects with severe Alopecia Areata (AA). Bempikibart (ADX-914) or matching placebo is administered subcutaneously in the clinic setting every 2 weeks for 24 weeks, with follow-up for 12 weeks. Subjects will be randomized 3:1 to drug vs placebo. All participants in Part A have completed participation.

Part B is a multicenter, open-label study comprised of a screening period of up to 4 weeks, a treatment period of 36 weeks, and a follow-up period of 16 weeks, for a total study duration of up to 56 weeks.

Part A Open Label Extension Cohort is a multicenter, open-label extension to assess the long-term efficacy, safety, and tolerability of bempikibart (ADX-914) in participants with severe AA who experienced hair regrowth as participants in Part A of the study. Participants enrolled in the Open Label Extension Cohort will receive bempikibart (ADX-914) for a duration of 6 months followed by a 16-week follow-up period.

Part B Open Label Extension Cohort is a multicenter, open-label extension to assess the long-term efficacy, safety, and tolerability of bempikibart (ADX-914) in participants with severe AA who experienced hair regrowth as participants in Part B of the study. Participants enrolled in the Open Label Extension Cohort will receive bempikibart (ADX-914) for a treatment period of 36 weeks, and follow-up period of 16 weeks, for a total study duration of up to 52 weeks.

Key Inclusion Criteria:

• Adult men and women, aged 18 to 75 years, inclusive, at the time of informed consent.
• Clinical diagnosis of severe to very severe alopecia areata, defined as the presence of ≥50% total scalp hair loss at screening and baseline as measured by the SALT score.

Key Exclusion Criteria:

• History of or diagnosis at screening of any another form of alopecia based on assessment by investigator.
• History (lifetime) or presence of hair transplants.
• History (lifetime) or presence of micropigmentation of the scalp (Note: Microblading of the eyebrows is permitted).
• Use of systemic, topical, or device-based therapy for AA.
• History of, recent, or current clinically serious viral, bacterial, fungal, or parasitic infection or mycobacterial infection or at risk of serious infection.