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Q32 BIO Building the Future of Immune Therapeutics August 2026
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Forward Looking Statements This presentationhas been prepared by Q32 Bio Inc. (“we”,“us,” “our,”“Q32” or the “Company”) and is made for informational purposes only. The informationset forth herein does not purport to be complete or contain all of the informationyou may desire.Statements containedherein are made as of the date of this presentation unless stated otherwise, and this presentationshall not under any circumstancescreate an implicationthat the informationcontained herein is correct as of any time after such dateor that information will be updated or revised to reflect information that subsequentlybecomes available or changes occurring after the date hereof. This presentationcontains forward-looking statements within the meaning of the U.S. PrivateSecurities Litigation Reform Act of 1995, as amended. Forward-looking statements can be identified by words such as “may,”“will,”“should,”“would,”“expect,”“anticipate,”“plan,” “likely,”“believe,”“estimate,”“project,” “intend,” “potential,”and similar expressions regarding future periods. These forward-looking statements include, but are not limited to, our beliefs, observations, expectations and assumptions regardingthe topline data from Part B of the SIGNAL-AA Phase 2a clinical trial and the safety,tolerability,clinical activity including biomarkerdata, potential efficacy and potential benefits of bempikibart, including plans and expectations for Part B of the SIGNAL-AA Phase 2a clinical trial, Q32 Bio's expectations and assumptions regarding the timing of reporting the findings from the Part B OLE of the SIGNAL-AA Phase 2a clinical trial, the expectations surrounding the potential, safety, efficacy, and regulatory and clinical progress of Q32 Bio’s product candidates, including bempikibart, and anticipated milestones, timing of anticipated registrational trials, data readouts and timing, the plans and timing of pre-clinical development regarding ADX-914-XL and Q32 Bio's beliefs, expectations and assumptions regarding the future of its business, future plans and strategies, including statements regarding the sufficiency of its cash and cash equivalents to provide financial runway through topline Phase 3 results from its planned registration-directed program evaluating bempikibart in patients with severe or very severe AA, and the US Alopecia Areata market size and potential commercial opportunities. Statements that are not historical facts are forward-looking statements.Forward-looking statementsare based on current beliefs and assumptions that are subject to risks and uncertaintiesand are not guaranteesof future performance. Actual results could differ materially from those contained in any forward-looking statement as a result of various factors,including, without limitation: the Company’s need for additional funding, which may not be available; failureto identify additional product candidates and develop or commercializemarketableproducts; the early stage of the Company’sdevelopment efforts; potential unforeseenevents during clinicaltrials could cause delays or other adverse consequences; risks relating to the regulatoryapprovalprocess; interim, topline and preliminarydata may change as more patient data become available,and are subject to audit and verification procedures that could result in materialchanges in the final data; Q32’s product candidates may cause serious adverseside effects; inability to maintain our collaborations,or the failure of these collaborations; our reliance on third parties, including for the manufacture of materials for our research programs,preclinical and clinical studies; failure to obtain U.S. or international marketing approval; ongoing regulatory obligations;effects of significant competition;unfavorablepricing regulations, third-party reimbursementpractices or healthcare reform initiatives; product liabilitylawsuits; securities class action litigation;the impact of global pandemics or public health emergencies and general economic conditions on our business and operations, including our preclinicalstudies and clinical trials; the possibilityof system failures or security breaches; risks relating to intellectual property and our ability to protect our patents and other proprietaryrights; significantcosts incurred as a result of operating as a public company; as well as those risk and uncertainties set forth more fully under the caption “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2025 as well as other risks detailed in our subsequentfilings with the United States Securities and ExchangeCommission. Any forward- looking statement made by us is based only on information currentlyavailable to us and speaks only as of the date on which it is made. We undertake no obligationto publiclyupdate any forward- looking statement, whether written or oral, that may be made from time to time, whether as a result of new information or future developmentsnor otherwise, unless required by law. Certain information contained in this presentationrelates to or is based on studies, publications, analyses,surveys and other data obtained from third-party sources and the Company’s own internal estimates and research. While the Companybelieves these third-party sources to be reliable as of the date of this presentation,it has not independentlyverified, and makes no representationas to the adequacy, fairness, accuracy or completenessof, any informationobtained from third-party sources. In addition, all of the market data included in this presentation involves a number of assumptions and limitations,and there can be no guarantee as to the accuracy or reliability of such assumptions. Finally, while we believe our own internal research is reliable, such research may not have been verified by any independentsource. 2
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Building The Future of Immune Therapeutics Beginning with Alopecia Areata (AA) Potential Standard of Care in Large AA Market with Significant Unmet Need • 700K1 AA patients in the U.S.; expected >$5B market by 20372 • Physicians and patients seek therapies with improved safety profile, i.e. no black box warning and minimal monitoring3 • Desire for a more patient-friendly profile including more durable efficacy3 Bempikibart Delivers Potent Dual IL-7/TSLP Inhibition • Proof-of-concept with durable response and safe redosing observed in SIGNAL-AA Part A • Meaningful efficacy data and well-tolerated safety profile in SIGNAL-AA Part B • Changes in Th2 clinical biomarkers and expected on-mechanism changes in T-cells, indicative of potent IL-7/TSLP inhibition 1Benigno M, et al. Clin Cosmet Investig Dermatol. 2020 Apr 1;13:259–266, 2QVIA quantitative market research, 3Survey conducted by IQVIA on behalf of Company Pipeline Expansion Opportunities • Evaluating opportunities for expansion into additional AA populations • Additional immunology and inflammation indications under consideration • Advancing ADX-914-XL, a half-life extended IL-7Rα antagonist advancing in pre-clinical development Experienced Team and Strengthened Cash Position • Management team with extensive public biotech and I&I expertise • Q2’26 cash balance of $106.3M; excludes proceeds from $200M financing in July • Runway through topline Phase 3 results from planned registration-directed program in patients with severe/very severe AA 3 • 2H’26: Part B expanded 36- week data and initial 52-week findings to be presented at a medical meeting • 1H’27: Expected initiation of registration-directed program in severe/very severe AA • 2H’27: Part B OLE results expected; enrollment and dosing remain ongoing • ADX-914-XL advancing in pre-clinical development AA Momentum Drives Near-Term Value Creation
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Q32 Pipeline: Restoring Immune Homeostasis in Patients with Severe Inflammatory and Autoimmune Disease Program Indication Discovery/ Preclinical Phase 1 Phase 2 Phase 3 Global Rights Anticipated Milestones & Recent Updates IL-7/TSLP PROGRAM Bempikibart (ADX-914) Alopecia Areata Wholly-owned Positive 36-week SIGNAL-AA Part B topline results reported; off-drug follow-up and OLE ongoing Plans to advance registration-directed program in 1H’27 Indication Expansion Additional indications under consideration ADX-914-XL (half-life extended) Multiple Advancing in pre-clinical development COMPLEMENT INHIBITOR PLATFORM ADX-097 Multiple ADX-097 development and commercial rights sold to Akebia Therapeutics ADX-096/ Platform Multiple Wholly-owned Evaluating strategic next steps for ADX-096 and complement inhibitor platform 4
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Bempikibart (ADX-914): (IL-7 / TSLP Receptor Inhibitor)
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Bempikibart: Bifunctional Antibody for T-cell Mediated I&I Diseases With Demonstrated Activity in Alopecia Areata IL-7 receptor • IL-7 regulatespathogenic Teff/ Tmem cells that suppress Treg cells in preclinical models • Blockade of IL-7Rα provides a novel mechanism for rebalancing Teff/mem and Treg function TSLP receptor • TSLP is central regulator of dendritic cell differentiation, Th2 cytokines • Blockade of TSLP function has potential to inhibit Th2 mediated inflammation and eosinophilic disease Bempikibart IL-7Rα antagonist antibody: Blocks IL-7 and TSLP signaling Biomarker Median % Changes Over Time Note: All data as of data cutoff of June 30, 2026; TSLP = Thymic Stromal Lymphopoietin 1In baseline high patients (part of exploratory biomarker analysis) Biomarker changes and clinical activity across SIGNAL-AA Part B: Supports IL-7Rα antagonist approach • CD3+ T cell decrease up to 44% • TARC1 decrease up to 41% • IgE1 decrease up to 29% • Eosinophils1 decrease up to 70% 6
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Bempikibart Addresses the Root of the Problem: Inhibition of Pathogenic T-cells that Directly Drive Hair Follicle Destruction and Suppress the Function of T-regs Hair Follicle Immune Dysregulation in Alopecia Areata Local inflammation and destruction of hair follicles driven by the infiltration of cytotoxic CD8+ T-cells and CD4+ T-effector and T-memory cells that suppress the function of Tregs Adapted from Curr Res Immunol. 2021 IFNγ GZMB Perforins CCL19 CCL20 IFNγ TNFɑ GZMB Perforins IFNγ IL-17 IL-22 IL- 23 TARC IgE IL-4 IL-13 NK NKG2D+ CD8+ NKG2D+ Th1 Th17 Th2 B DC Treg TRM IL7Rα γc IL7Rα TSLPR IL-7 TSLP CD4+ NKG2D+ TCR MHC NKG2D MIC-A/B Rezpegaldesleukin Dupilumab IMG-007 Bempikibart Bempikibart Amlitelimab IL7Rα γc IL7Rα TSLPR Bempikibart Bempikibart Bempikibart is designed to address the root cause of T-cell mediated inflammation by two primary mechanisms: • Inhibition of cytotoxic CD8+ T-cells • Inhibition of CD4+ T-effector and memory cells that suppress the function of Tregs Bempikibart’s differentiated MoA addresses the root of inflammation that drives hair follicle destruction and allows for the restoration of immune tolerance EpidermisDermis 7
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SIGNAL-AA First-in-Patient Observations of Durable Response Supported by Preclinical Data Describing IL-7 Mechanistic Modulation of Teff/mem cells 8 Broad literature describing effects of IL-7Rα on Teff/mem cells Preclinical evidence of long-term durable effects following IL-7Rα antibody treatment Autoimmune Disease Imbalancein Teff/memvs Treg function Homeostasis Immune suppression Immune activation IL-7 IL-7R Ab Treatment with IL-7Rα Ab Restores balance of Teff/memvs Treg function Type 1 Diabetes Model Collagen Induced Arthritis Model Tuberculin Challenge Model • Anti-IL-7R treatment markedly reduces/delays diabetes onset in NOD1 mice • Effect persists 7+ weeks after secession of dosing • Anti-IL-7R treatment markedly reduces arthritis in mice • Effect persists 10+ weeks after secession of dosing • One dose of anti -IL-7R markedly reduces tuberculin induced DTH response in baboons • Effect persists for 1+ year, BCG vaccine restores response Proposed Mechanism TregTeff/mem Treg Teff/mem Treg Teff/mem Function amplified Function suppressed Selective Teff/mem inhibition
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Bempikibart SIGNAL Program In Severe/Very Severe Alopecia Areata Designed To Enable Registrational Studies As Next Step Part A Part A Part A 24-Week Primary Endpoint Completed 4Q’24; Part A OLE Completed 2Q’26 SIGNAL-AA Clinical Program Part A Findings: • Encouraging clinical activity observed with 24 weeks of dosing, including robust pharmacologic data and a well-tolerated safety profile • Evidence of deepening effect following dosing cessation, supportive of potential remittive effect Part A OLE Findings: • Responders, non-responders and placebo Part A patients enrolled; Range of off-drug time: 26-55 weeks • Generally well tolerated with redosing; minimal ADA and no safety issues • Durable or further hair growth observed in patients who maintained hair prior to OLE • Results provide examples of sustained,durable response, butsupport importance of maintenance dosing regimen (e.g., monthly, bi-monthly, quarterly) vs. extended off- drug windows Summary: • Established proof-of-concept in alopecia areata • Durable and sustained responses with dosing in some patients out to more than 100 weeks • Generally well tolerated safety profile during treatment period and during redosing Part B 36-Week Primary Endpoint Complete 3Q’26; Off-Drug Follow-Up and OLE Ongoing Primary Endpoint Complete; Off-Drug Follow-Up Ongoing: • Open-label trial evaluating 36 weeks of bempikibartdosing (completed) • 16-week off-drug follow-up through Week 52 is ongoing to assess remittive effect andprovide insight into long-term maintenance schedule Part B OLE: • OLE enables follow-up with re-dosing after 16-weeks off-drug; OLE to evaluate longer term every-other-week and once-monthly dosing regimens • OLE insights, alongside results from Part B off-drug follow-up, to inform long-term maintenance schedule Note: Data cutoff as of June 30, 2026 9
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Loading dose regimen Longer duration of treatment (36 Weeks from 24 Weeks) Maximum duration of current episode of 4 years Central confirmation of diagnosis SIGNAL-AA Phase 2a Part B: Builds Upon Part A Includes Loading Regimen and Dosing Through 36 Weeks Screening with Central Eligibility Review Key Changes from Part A Placebo (n=81) Q2W Week 36 Week 0 Week 52 Bempikibart 200mg (n= 33) Efficacy & Safety Follow-up Loading Regimen: 200 mg weekly (4 doses) Continued Dosing: 200 mg Q2W (32 weeks) Key Inclusion/Exclusion Criteria • Severe/Very Severe Alopecia Areata (SALT 50-100) • No other forms of Alopecia • Duration of current episode < 4 yrs • Prior use of JAKi’s allowed with appropriate wash-out Design Elements Follow-Up 16 Weeks Off-Drug PeriodTreatment Period Primary and Other Key Endpoints • Primary Analysis: mITT mean percent change from baseline SALT at Week 36 • Other Key Endpoints: percentage of patients achieving relative and absolute SALT score improvements at Week 36 Note: JAKs = Janus Kinase inhibitors 10 Longer-term Q2W or QM Dosing OLE Post Week 52
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SIGNAL-AA Phase 2a Part B: Baseline Demographics Note: mITT population excludes (i) 5 early term patients who discontinued prior to Week 18, including 2 who never for returned for SALT assessment post-baseline - none of which were related to the safety of bempikibart; and (ii) 3 patients with unstable disease as per pre-specified criteria in the Part B SAP. Characteristics mITT Population N = 25 ITT Population N = 33 Actual Baseline SALT Score Mean [SD] 76.9 [17.2] 75.6 [17.8] Median 79.9 72.7 Min, Max 50.9, 100.0 50.9, 100.0 Baseline SALT Score, n (%) ≥50 to <95 19 (76.0) 25 (75.8) ≥95 to 100 6 (24.0) 8 (24.2) Duration of Current Episode, years Mean [SD] 2.07 [1.1] 2.07 [1.2] Median 2.41 2.41 Min, Max 0.5, 3.8 0.5, 3.8 Prior Oral JAK Inhibitor Exposure, n (%) Yes 10 (40.0) 12 (36.4) Country, n (%) Canada 4 (16.0) 6 (18.2) United States 21 (84.0) 27 (81.8) Characteristics mITT Population N = 25 ITT Population N = 33 Age, years Mean [SD] 41.92 [15.0] 40.7 [14.0] Median 39.0 38.0 Min, Max 20, 74 20, 74 Sex, n (%) Female 19 (76.0) 24 (72.7) Race, n (%) Asian 1 (4.0) 1 (3.0) Black or African American 2 (8.0) 3 (9.1) White 19 (76.0) 25 (75.8) Others 3 (12.0) 4 (12.1) 11
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PK Results in Part B: Data Supports Steady State ~10 Weeks Earlier Than Part A Part A Part B Mean Ctroughs ~3 fold higher in the first month of dosing compared to Part A Negligible ADA with no impact on PK No change in the known safety profile of bempikibart Achieved steady state concentrations ~10 weeks earlier Time t dy Weeks Bempikibart ean Con entra on g mL Note: All data as of data cutoff of June 30, 2026 12
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Part B (mITT): Mean % Change from Baseline at Week 36 Note: All data as of data cutoff of June 30, 2026; All calculations are based on pre-specified criteria defined in Part B SAP. 1Prespecified sensitivity on mean change from baseline in SALT score using MMRM: LS mean change is 39.1% 35.3% mean reduction in SALT score (Severe and Very Severe population1) Robust improvement in both Severe and Very Severe populations: • 37.8% mean reduction in SALT score (Severe Population only) • 27.4% mean reduction in SALT score (Very Severe Population only) Response sustained and deepened throughout treatment period 13
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Part B (mITT): Clinically Meaningful SALT-20 Achievement at Week 36 % Change from Baseline at Week 36 mITT (n=25) ITT (n=33) SALT-20 at Week 36: n (%) 10 (40.0%) 10 (30.3%) Note: All data as of data cutoff of June 30, 2026; All calculations are based on pre-specified criteria defined in Part B SAP. SALT-20 Responders • Responses seen in severe and very severe patients • Baseline SALT scores in patients achieving SALT-20 range from 51 to 100 Part B Severe Population (mITT, n=19) Part B Very Severe Population (mITT, n=6) 14
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Robust Part B Clinical Activity in Alopecia Areata Supports Potential for Paradigm Shift to Biologics SIGNAL-AA Part B Efficacy Results at Week 36 mITT population ITT population SALT-20 (% pts) 40.0% (10/25) 30.3% (10/33) SALT30 (% pts) 44.0% (11/25) 33.3% (11/33) SALT50 (% pts) 44.0% (11/25) 33.3% (11/33) On mITT, 40.0% of patients achieved SALT-20 On full ITT, 30.3% of patients achieved SALT-20 Note: All data as of data cutoff of June 30, 2026; All calculations are based on pre-specified criteria defined in Part B SAP. 15
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Patient with Severe AA with Robust Response and Durability Off-Drug: SALT-10 at Week 24 and 36, SALT-0 at Week 44; Maintained Off-Drug First SALT-0 99.4% SALT reduction at Week 36 which improved to 100% SALT reduction at Week 44;maintained through Week 52 and enrolled in OLE • 48-year-old female; Duration of current episode: 1.2 years Baseline Week 36 Week 52 Treatment Period 16 Weeks Off-Drug 6 12 1 24 3 36 1 2 3 4 6 7 1 ALT ore T ro g t dy Treatment t dy Weeks ALT ore 16Note: Patient achieved central review verification of eligibility for diagnosis and baseline SALT score >50.
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Patient with Severe AA with Robust Response and Durability Off-Drug: SALT-20 at Week 24, SALT-10 by Completion Date; Maintained Off-Drug SALT-20 at Week 24; 89.8% SALT reduction at Week 32; last dose at Week 30 to focus on family planning; patient remains in off-drug follow-up with maintenance of response • 33-year-old female; Duration of current episode: 1.4 years • Prior JAK experienceBaseline Week 32 Week 42 Treatment Period 12 Weeks Off-Drug ALT ore T ro g t dy Treatment t dy Weeks ALT ore 6 12 1 24 3 36 1 2 3 4 6 7 1 17Note: Patient achieved central review verification of eligibility for diagnosis and baseline SALT score >50.
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Patient with Severe AA with Robust Response and Deepening Response Off-Drug: SALT-20 at Week 36, SALT-10 at Week 48 and 52 SALT-20 at Week 36; 62.8% SALT reduction at Week 36 which improved to SALT-10 in off-drug follow-up; maintained through Week 52 and enrolled in OLE • 41-year-old female; Duration of current episode: 2.5 years Baseline Week 36 Week 52 Treatment Period 16 Weeks Off-Drug ALT ore T ro g t dy Treatment t dy Weeks ALT ore 6 12 1 24 3 36 1 2 3 4 6 7 1 18Note: Patient achieved central review verification of eligibility for diagnosis and baseline SALT score >50.
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Patient with Very Severe AA with Robust Response and Durability Off-Drug: SALT-20 at Week 36; Maintained Off-Drug SALT-20 in patient with very severe AA at Week 36; 79% SALT reduction at Week 36; hair growth maintained through Week 52 and now enrolled in OLE • 32-year-old male; Duration of current episode: 3.2 years Baseline Week 36 Week 52 Treatment Period 16 Weeks Off-Drug ALT ore T ro g t dy Treatment t dy Weeks ALT ore 6 12 1 24 3 36 1 2 3 4 6 7 1 19Note: Patient achieved central review verification of eligibility for diagnosis and baseline SALT score >50.
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Bempikibart SIGNAL-AA Part B: Most Commonly Reported Treatment Emergent Adverse Events; No Severe or Higher AEs Bempikibart N=33 N (% patients reporting at least one TEAE) 31 (93.9) Most Common TEAEs (>5%) Preferred Term Gr1 (Mild), n (%) Gr2 (Mod), n (%) Gr3 or Higher (Sev), n (%) Injection site reaction 12 (36.3) 0 (0.0) 0 (0.0) Upper respiratory tract infection 7 (21.2) 5 (15.1) 0 (0.0) Gastroenteritis 1 (3.0) 4 (12.0) 0 (0.0) Urinary tract infection 0 (0.0) 3 (9.0) 0 (0.0) Lymphocyte count decreased 3 (9.0) 0 (0.0) 0 (0.0) Fatigue 2 (6.1) 0 (0.0) 0 (0.0) Presyncope 2 (6.1) 0 (0.0) 0 (0.0) Conjunctivitis 0 (0.0) 2 (6.1) 0 (0.0) Influenza 0 (0.0) 2 (6.1) 0 (0.0) Eczema 0 (0.0) 2 (6.1) 0 (0.0) Lower respiratory tract infection 1 (3.0) 1 (3.0) 0 (0.0) Headache 1 (3.0) 1 (3.0) 0 (0.0) Muscle strain 1 (3.0) 1 (3.0) 0 (0.0) Myalgia 1 (3.0) 1 (3.0) 0 (0.0) Note: All data as of data cutoff of June 30, 2026; If a subject experienced more than one AE, the subject is counted only for the maximum severity; ISR = Injection Site Reaction • ISR incidence is 4% across all Part B dose administrations • In patients reporting ISR, 8 out of 12 only had one • All ISRs reported to date were mild and resolved with no intervention 20
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Bempikibart SIGNAL-AA: Part B Builds on Prior Proof Of Concept in Alopecia Areata Demonstrating Robust Clinical Activity at 36 Weeks Mean SALT change (mITT analysis1) 21 Bempikibart continued to demonstrate a favorable safety profile; negligible ADA No Grade 3 or higher AEs and no new safety signals Robust clinical activity Week 36 Results Results demonstrate potential for differentiated profile for the treatment of alopecia areata Profile supports further expansion in alopecia areata (registration-directed program for severe/very severe, plans for development in adolescent, moderate alopecia areata) Off-drug follow-up through Week 52 and Part B OLE remain ongoing 35.3% SALT-20 response (mITT analysis)40.0% 30.3% SALT-20 response (ITT analysis) Note: All data as of data cutoff of June 30, 2026; All calculations are based on pre-specified criteria defined in Part B SAP; SALT = Severity of Alopecia Tool; OLE= Open-Label Extension; ADA = Anti-Drug Antibody 1Prespecified sensitivity on mean change from baseline in SALT score using MMRM: LS mean change is 39.1% 21
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Bempikibart May Redefine the Long-Term Management of Alopecia AreataWith Emerging Well-Tolerated, Selective and Efficacious Biologic Profile 1 Overcome JAKi Safety Concerns2 Unlock Large, Undertreated Population 3 Deliver Durable Control for Chronic Disease 5 Simplify Real-World Use and Access4 Set the Bar for Biologics in Alopecia Areata Development of biologics in Alopecia Areata have lagged the JAK inhibitors: Unique dynamic not seen elsewhere in the broader I&I landscape Target Product Profile for Bempikibart Development 22 Novel mechanism has delivered meaningful clinical efficacy data with manageable injection site reactions observed to date Non-JAKi biologic profile – and potential absence of class-driven black box warning – may mitigate safety concerns currently limiting alopecia areata treatment uptake Selective biologic profile with durable responsiveness provides potential dosing flexibility ideal for management of a lifelong condition with expectations of step-down to longer-term maintenance regimen (e.g., monthly, bi-monthly, quarterly dosing) Potential for reduced monitoring burden relative to JAKi’s and a physician- and patient- friendly profile to improve adherence with potential for at-home dosing Aiming to address patients and physicians unwilling to initiate or persist on existing therapies
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Bempikibart SIGNAL-AA Program In Severe/Very Severe Alopecia Areata Supports Registration-Directed Program • Completion of SIGNAL-AA Part B through week 52; expanded 36-week and initial 52-week findings to be presented at a medical meeting in 2H’26 • Registration-directed program to initiate 1H’27 subject to planned regulatory discussions later this year • Part B OLE enrollment and dosing ongoing; results to be presented in 2H’27 • Evaluating opportunities to broaden development in expanded AA populations and additional I&I indications Next Steps • Alopecia areata is a large and underserved patient population with significant unmet need • Proof-of-concept with durable response and safe redosing observed in SIGNAL-AA Part A • Meaningful efficacy data and well-tolerated safety profile with 36-week dosing in SIGNAL-AA Part B • Favorable safety and tolerability profile with low rates of ISRs across SIGNAL-AA program Bempikibart for Alopecia Areata ISR = Injection Site Reaction Differentiated target product profile of bempikibart supports the potential to become standard of care as an efficacious, durable and safe targeted biologic therapy for the treatment of alopecia areata 23
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Alopecia Areata Unmet Need and Commercial Opportunity
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“There’s no middle ground for ease of access, safety, and efficacy in current therapies—either a benign topical or a chronic pill with a black box warning—and many patients remain on subpar therapies due to hesitation around JAKi side effect risks.” Alopecia Areata Has Life-Altering Impact and Significant Unmet Need With Limited Treatment Options, Including JAK Inhibitors Carrying Black Box Warnings Key Findings From Survey of 50 U.S. Dermatology Healthcare Providers on Unmet Need1 Improved safety profile (no black box warning) More durable efficacy Minimal lab monitoring requirements - US Dermatologist, Community Practice Alopecia areata unmet need persists “There's a large unmet need. Many patients don't want JAK inhibitors and there are no other advanced options for them." - US Dermatologist, Community Practice 1Survey conducted by IQVIA on behalf of Company 25
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The US Alopecia Areata Market is Growing Despite Remaining Unmet Need By 2037, Estimated to be >$5B US Opportunity US Alopecia Areata Prevalence: ~800k patients Treated with Advanced Therapies: ~300k patients 2 Future US Alopecia Areata Market Size (2037F) Est. >$5 Billion Addressable: ~530k patients Estimated Historical and 2026 Projected US Alopecia Areata Net Sales (JAKi alopecia areata net sales est., USD)1 Total US Market Opportunity 2022 2023 2024 2025 2026 54M 153M 261M 352M 500M 26
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Bempikibart Expansion Opportunities
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SIGNAL Phase 2 Program Meaningful effect on Th2 biomarkers observed Eosiniphils, IgE, TARC 28 Opportunities Beyond AA: Potential to Expand into a Broad Range of Th1 and Th2 Mediated Diseases SIGNAL Phase 2 Program Results support the potential for long term, durable responses Suggestive of Teff/Tmem impact
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Summary: Financial Overview and Anticipated Milestones
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• Q2’26 cash balance of $106.3M and proceeds from $200M July 2026 public offering expected to provide runway through topline Phase 3 results from planned registration-directed program in patients with severe/very severe AA • Approximately 29.8M shares outstanding (35.9M including pre-funded warrants) Financial Overview Anticipated MilestonesRunway through Phase 3 topline results of registration-directed AA program • 2H’26: Part B expanded 36-week data and initial 52-week findings to be presented at a medical meeting • 1H’27: Expected initiation of registration-directed program in severe/very severe AA • 2H’27: Part B OLE results expected; enrollment and dosing remain ongoing • ADX-914-XL advancing in pre-clinical development Q32 Bio Has Significant Potential to Unlock Near-Term Value Creation 30
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APPENDIX
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Tissue-Targeted Complement Platform: Currently EvaluatingStrategic Options for ADX-096 and Other Complement Programs
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Q32 Tissue-targeted Platform ValueProposition: Designed to Enable Clinical Profile Superior to Systemic Complement Inhibitors The Opportunity • Enhanced activity through tissue targeting: Differentiatedapproach to driving efficacy by inactivating convertases directly at site of destruction • Reduced treatment burden: SC route with QW dosing; potential for Q2W • Improvedrisk/benefit profile: Designed to maximizetherapeutic index while maintaining intact immune surveillance; broader indication potential 33 The Unmet Need • Limited activity: Reliant on systemic blockade for impact on affected organ • High doses, frequent administration required: High abundance, rapid turnover of most target complement proteins • Infection risk: Complement plays critical role in combating infection; systemic blockade increases risk
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Tissue-TargetedComplement Platform: Potential for Broad Applicability in Complement-Driven Diseases Platform underpinned by tissue-targeted approach designed to inhibit complement activation in the tissue while minimizing systemic complement blockade T echnologybroadly applicable Strong scientific rationale supporting potential in multiple therapeuticareas Therapeutic Modularity & Optionality Negative regulator protein Targetingagent Dysregulatedlocal complement is a key factor in autoimmune-related diseases in multiple organs Renal DermatologyOphthalmology Vascular Tissue-Targeted Complement Platform 34