Q32 Bio reports results from SIGNAL-AA Phase 2a clinical trial

Q32 Bio (QTTB) announced topline results from the SIGNAL-AA Phase 2a signal finding clinical trial evaluating bempikibart, or ADX-914, which identified encouraging clinical activity in patients with alopecia areata, or AA. The Company plans to expand the SIGNAL-AA Phase 2a clinical trial and enroll additional patients evaluating bempikibart in AA. The Company is also providing an update on the SIGNAL-AD clinical trial in patients with atopic dermatitis, or AD. Although the Company is reporting promising findings in Part A, the trial did not meet its primary endpoint in Part B. SIGNAL-AA is a Phase 2a, randomized, double-blind, placebo-controlled, multi-center clinical trial evaluating bempikibart in adult patients with severe and very severe AA treated over 24 weeks, with follow-up through 36 weeks. The study is being conducted to evaluate the efficacy and safety of bempikibart 200 mg administered subcutaneously, or SC, every-other-week, or Q2W, compared to placebo. A total of 44 patients were enrolled in the trial with a primary endpoint of the mean relative percent change in SALT score at 24 weeks compared with baseline. Following database lock, one site was excluded from the efficacy analysis based on marked protocol violations of entry criteria. This resulted in the removal of three placebo patients, rendering the planned statistical analyses for the primary endpoint inappropriate due to the reduced sample size. On a post-hoc analysis of the remaining per-protocol population of patients with AA, bempikibart demonstrated an improvement in hair re-growth compared to placebo. At week 24: patients treated with bempikibart showed a mean reduction in SALT score of 16% in the bempikibart group vs a reduction of 2% in the placebo group. A Wilcoxon Rank Sum test yielded a p-value of 0.045. At week 24: 9% of bempikibart patients in the trial achieved a SALT-20 compared to 0% in placebo. At week 26: 13% of bempikibart patients achieved SALT-20 compared 0% in placebo. Bempikibart was observed to be safe and well tolerated in the SIGNAL-AA trial. There were no serious adverse events, orSAE, 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 clinical trial to further evaluate bempikibart in AA, including a loading regimen. The Company will defer enrollment into the planned Phase 2 clinical trial of ADX-097 in ANCA-Associated Vasculitis, 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. Topline Results from SIGNAL-AD Phase 2a Clinical Trial: SIGNAL-AD is a two-part Phase 2a, randomized, double-blind, placebo-controlled, multi-center clinical trial evaluating bempikibart in adult patients with persistent, moderate-to-severe AD. Part A (n=15) was conducted to evaluate safety, pharmacokinetics, and to enable dose selection for Part B of the clinical trial. Part A was randomized 2:1 between bempikibart and placebo in each of two dose cohorts of 2mg/kg or 3mg/kg Q2W SC for 12 weeks. 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. These results include: A reduction in Th2 biomarkers, including TARC, IgE and eosinophils, which was consistent with the type of biomarker impact previously observed with other agents that have demonstrated utility in atopic dermatitis, such as IL-4Ralpha, IL-13 and OX40 ligand-targeted agents.