Q32 Bio Inc. Announces Positive 36‑Week SIGNAL‑AA Trial Results

What Happened

• On September 30, 2026, Q32 Bio Inc. announced additional 36‑week treatment results and initial 16‑week off‑drug follow‑up findings from Part B of the SIGNAL‑AA Phase 2a trial of bempikibart, presented in a late‑breaking oral and poster at EADV 2026. Bempikibart is a fully human anti‑IL‑7Rα antibody designed to block IL‑7 and TSLP signaling.
• Part B enrolled 33 patients with severe or very severe alopecia areata (baseline SALT 50–100). Dosing was 200 mg SC weekly for four loading doses, then 200 mg every other week through Week 36. The prespecified modified intent‑to‑treat (mITT) analysis included 25 patients.

Key Details

• Efficacy at Week 36 (mITT): mean SALT score reduction of 35.3%; SALT‑20 achieved in 40.0% (10/25), SALT‑30 in 44.0% (11/25), SALT‑50 in 44.0% (11/25). ITT rates (33 pts) for SALT‑20 and SALT‑30 were 30.3% and 33.3%, respectively.
• Prior oral JAK inhibitor subgroup (mITT): among 10 prior JAK‑treated patients, mean SALT reduction was 48.3% in prior JAK responders vs. 4.8% in prior JAK non‑responders; JAK‑naïve patients showed 44.1% mean reduction.
• Durability off‑drug: 18 patients entered the 16‑week off‑drug follow‑up. At Week 52 (16 weeks off drug) 44% reached SALT‑20, 61% SALT‑30, and 50% SALT‑50. Of 12 patients who had on‑treatment hair growth at Week 36, 100% maintained (≤20‑point SALT worsening) and 42% deepened response off‑drug.
• Safety/PK/ADA: no treatment‑related serious adverse events or Grade ≥3 AEs reported; most common TEAE was injection‑site reaction (36.3%), mild and transient. PK/PD data support the loading regimen; negligible anti‑drug antibodies observed.

Why It Matters

• These Phase 2a Part B results show clinically meaningful hair regrowth and off‑drug durability in a small, severe AA population, with a favorable safety and biomarker profile. The company says the data support advancing bempikibart into a registration‑directed program in the first half of 2027, subject to planned regulatory discussions in the second half of 2026. Investors should note upcoming readouts: ongoing open‑label extension data expected in the second half of 2027.