Q32 Bio (QTTB) investor relations material

Company background and pipeline focus

• Founded in 2017 to develop therapeutics targeting key inflammatory and autoimmune pathways, aiming for immune system homeostasis rather than broad immunosuppression.

• Initially advanced complement system regulators, then in-licensed bempikibart, an IL-7 receptor alpha subunit antibody, for its bifunctional activity and best-in-class potential.

• Bempikibart targets both IL-7 and TSLP pathways, crucial in T cell biology and TH2 responses, with durable effects shown in preclinical and clinical studies.

• Demonstrated low immunogenicity and favorable PK/PD properties, supporting subcutaneous administration and durable responses in clinical trials.

• Advanced through phase I in healthy volunteers and phase II in atopic dermatitis and alopecia, showing strong efficacy and durability in alopecia areata.

Market opportunity and competitive landscape

• Estimated 700,000 AA patients in the U.S., projected to grow to 800,000, with about 500,000 addressable for advanced systemic therapy.

• U.S. market opportunity valued at least $5 billion, with global potential even larger.

• JAK inhibitors in AA have low market penetration, with $500 million annualized U.S. sales and 30-40% growth, but limited by safety concerns and black box warnings.

• Biologics like bempikibart are expected to become preferred first-line treatments due to better safety and durability.

• Entry of new JAKs (e.g., RINVOQ) may expand awareness but does not address class limitations; biologics anticipated to drive future market expansion.

Clinical development and trial design

• Phase II SIGNAL-AA Part A showed statistically significant hair regrowth and durable off-drug responses, prompting resource focus on bempikibart.

• Part B implemented central review, refined inclusion criteria, loading dose, and extended dosing to 36 weeks, aligning with contemporary standards.

• Part B results: mean SALT reduction ~35%, SALT 20 rates of 40% (mITT) and just over 30% (ITT), with all endpoints pre-specified.

• Loading dose and longer dosing duration contributed to deeper reductions and faster achievement of steady state.

• 16-week off-drug follow-up data expected in the second half of the year, aiming to demonstrate durability and differentiation from JAKs.