Getting Hairy: Initiating Coverage at OW + Derm Survey

Research evidence excerpt

Getting Hairy: Initiating Coverage at OW + Derm Survey

May 18, 2026

QTTB – Investment Thesis

Executive Summary

Q32 Bio (QTTB) is a clinical-stage biotech company developing bempikibart, an anti-IL7-Rα antibody for the treatment of alopecia

areata (AA), an autoimmune disease that leads to patchy or total hair loss.

The only approved systemic agents in AA are JAK inhibitors, which work quite well, but all carry a boxed warning for elevated risk of

cardiovascular events, thrombosis, cancer and infections, and must be taken indefinitely. There are no approved biologics yet. A few

are in early clinical development, including bempikibart.

The biology supports bempikibart as a differentiated approach in AA. Bempikibart has been designed to broadly impact Th1

inflammation, through blocking IL-7 signaling, and Th2 inflammation, blocking TSLP. AA was historically viewed as a Th1-driven

disease, but biopsy data increasingly shows a dual Th1/Th2 pathology.

Alopecia areata is measured using the SALT score, which stands for severity of alopecia tool. It’s a measure of the percentage of

hair loss across the scalp, ranging from 0 (no hair loss) to 100 (total hair loss). A higher score means worse disease.

Key efficacy metrics include % change from baseline (CFB) in SALT and % of patients achieving SALT score of less than 20 (i.e., 80%

hair coverage), SALT≤20, the Ph3 endpoint for JAKs.

Unlike other derm scores, such as PASI90 (psoriasis) and EASI75 (atopic dermatitis), which measure improvement relative to

baseline, SALT≤20 is an absolute threshold, independent of where the patient started. This means baseline scores are highly

influential in AA studies.

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