Q32 Bio (QTTB) investor relations material

Program updates and clinical progress

• Advancing bempikibart (IL-7 receptor alpha) in alopecia, with phase II-B enrollment and dosing ongoing; results expected in the first half of next year.

• Phase II-A showed statistically significant hair improvement at week 24, with durable responses and a favorable safety profile.

• Modifications for phase II-B include a loading dose regimen, shifting the primary endpoint to week 36, and stricter inclusion criteria to improve responsiveness.

• Early phase II-B data indicate earlier signs of responsiveness, including in severe and very severe patients.

• Bringing trial operations in-house has reduced dropouts and improved patient selection.

Mechanism of action and differentiation

• Bempikibart targets the IL-7 receptor alpha, blocking both IL-7 and TSLP, which are upregulated in alopecia patients' hair follicles.

• Blocking this pathway leads to durable responses, with some patients experiencing continued hair regrowth months after treatment cessation.

• The drug's immunomodulatory profile differs from JAK inhibitors, offering durable effects without rapid relapse after stopping treatment.

• No clear biomarkers yet for early responders, but ongoing analysis may provide further insights.

Dosing strategy and trial design

• Loading dose in phase II-B achieves higher and earlier steady-state drug levels, aiming for faster and deeper responses.

• Modified inclusion criteria now limit episode duration to four years, aligning with benchmarks from JAK inhibitor trials.

• The primary endpoint moved to week 36, considered more appropriate for immunomodulators.

• Future trials may explore higher doses or dose-ranging, given the favorable safety margin.