On Wednesday, Q32 Bio Inc. (NASDAQ:QTTB) revealed topline results from the SIGNAL-AA Phase 2a signal finding trial evaluating bempikibart (ADX-914) for alopecia areata (AA).

The company plans to expand the SIGNAL-AA Phase 2a clinical trial and enroll additional patients evaluating bempikibart in AA.

The company said the trial did not meet its primary endpoint in Part B. Q32 Bio plans to review the results.

Following database lock, one site was excluded from the efficacy analysis based on marked protocol violations of entry criteria, resulting in the removal of three placebo patients.

Due to the reduced sample size, the planned statistical analyses for the primary endpoint were rendered inappropriate.

On a post-hoc analysis of the remaining per-protocol population of patients with AA (n=27), bempikibart demonstrated an improvement in hair regrowth compared to placebo:

• At week 24: patients treated with bempikibart showed a mean reduction in baseline Severity of Alopecia Tool (SALT) score of 16% in the bempikibart group vs a reduction of 2% in the placebo group.
• At week 24: 9% of bempikibart patients in the trial achieved a SALT-20 (SALT score less than or equal to 20) compared to 0% in placebo.
• At week 26: 13% of bempikibart patients achieved SALT-20 compared to 0% in placebo.

Bempikibart was observed to be safe and well-tolerated in the SIGNAL-AA trial. There were no serious adverse events (SAE) or Grade 3 or higher adverse events related to treatment.

Q32 Bio plans to enroll approximately 20 additional patients in a Part B expansion of the SIGNAL-AA Phase 2a trial to evaluate bempikibart in AA, including a loading regimen.

The company will defer enrollment into the planned Phase 2 trial of ADX-097 in ANCA-Associated Vasculitis (AAV), previously expected to begin in 2025, to focus efforts on continued enrollment in the ongoing bempikibart AA and ADX-097 renal basket Phase 2 clinical trials.

The company also provided an update on the SIGNAL-AD clinical trial in patients with atopic dermatitis (AD).

In Part A, at week 14, the average EASI (eczema) score improvement from baseline was 58% in patients treated with 2mg/kg Q2W SC, 84% in patients treated at 3mg/kg Q2W SC, and 72% on a pooled basis, compared to 38% in patients treated with placebo.

Part B evaluated the efficacy and safety of bempikibart compared to the placebo.

The primary endpoint is the mean percent change in the Eczema Area and Severity Index (EASI) score from baseline to week 14.

At week 14, data from Part B demonstrated that patients treated with bempikibart showed a 74% improvement in average EASI from baseline, compared to 76% for the placebo group (p= not statistically significant).

Across SIGNAL-AD and SIGNAL-AA, bempikibart at 200mg Q2W SC demonstrated favorable PK and target engagement as demonstrated by substantial reductions in biomarkers of Th2 and Th1.

Price Action: QTTB stock is down 67.1% at $8.04 at last check Wednesday.

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