Cabaletta Bio, Inc. · NASDAQ:CABA

Cabaletta Bio — Investor Presentation (September 2026)

50 slides from Cabaletta Bio's investor presentation, September 2026

1. Slide 1: Corporate Presentation

   Corporate Presentation SEPTEMBER 2026 © 2026 Cabaletta Bio. All rights reserved.

2. Slide 2: Disclaimer

   Disclaimer This presentation, including any printed or electronic copy of these slides, the talks given by the presenters, the information communicated during any delivery of the presentation and any question and answer session and any document distributed at or in connection with the presentation (

3. Slide 3: Develop and launch the first curative targeted cellular therapies for patients with autoimmune diseases

   Develop and launch the first curative targeted cellular therapies for patients with autoimmune diseases 3

4. Slide 4: Rese-cel: Delivering on the promise of CD19-CAR T in autoimmunity

   Rese-cel: Delivering on the promise of CD19-CAR T in autoimmunity 2H27 BLA planned to include adult and juvenile DM for potential PRV; PC-free & automated mfg advancing Rese-cel Phase 1/2 data with preconditioning: 64 myositis, SSc, lupus and MG patients; up to 1.5 years of f/u1 • Data suggest a sin

5. Slide 5: Immune reset with a single infusion and a favorable safety profile

   Immune reset with a single infusion and a favorable safety profile Beyond myositis and scleroderma, advancing innovation with PC-free rese-cel & industrialized automated mfg Transformative Value Elimination of PC Automated Manufacturing Proposition ▪ Expands the market ▪ Minimizes capital investment

6. Slide 6: Innovative clinical strategy to support accelerated regulatory path

   Innovative clinical strategy to support accelerated regulatory path Myositis and SSc programs advancing to registrational trials with preconditioning Program Trial Preclinical Phase 1/2 Registrational Dermatomyositis / Antisynthetase syndrome RMAT Plan to include JDM data in 2H27 myositis RESET-Myos

7. Slide 7: RESET program advancing trials in a broad portfolio of diseases

   RESET program advancing trials in a broad portfolio of diseases Broad portfolio of trials designed to address high unmet need and realize the potential of rese-cel PC-free PC-free PC-free evaluation evaluation evaluation Myositis SLE/LN SSc gMG PV > > > > Typical onset middle age Affects young women

8. Slide 8: Rese-cel: Construct Design, PK/PD and Safety Data

   Rese-cel: Construct Design, PK/PD and Safety Data 8

9. Slide 9: Rese-cel: CD19-CAR T specifically designed for autoimmunity

   Rese-cel: CD19-CAR T specifically designed for autoimmunity Risk-benefit profile reinforced by compelling clinical responses with safety data supporting outpatient use5,8 Rese-cel designed to optimize risk-benefit for autoimmune patients Fully human 1) Manufacturing uses standard, well-characterized

10. Slide 10: RESET clinical trials have consistent design principles

    RESETTM clinical trials have consistent design principles1 Many of the RESET trials share common elements of preconditioning, dose, and study design Day -5 to Day -3 Day 1 Day 29 Study follow-up through Year 3† Leukapheresis Single weight- Primary endpoint: Additional Endpoints Screening and rese-ce

11. Slide 11: Rese-cel expansion & B cell kinetics across indications

    Rese-cel expansion & B cell kinetics across indications* Peak rese-cel expansion and transient peripheral B cell depletion occurred by ~2 weeks post infusion​​ RESET-Myositis† RESET-SLE RESET-SSc RESET-MG Rese-cel Pharmacokinetics Rese-cel Pharmacokinetics Rese-cel Pharmacokinetics§ Rese-cel Pharmac

12. Slide 12: Demographics & CRS/ICANS in first 64 rese-cel patients by indication

    Demographics & CRS/ICANS in first 64 rese-cel patients by indication Across 4 RESET studies, 94% of patients have either no CRS or Grade 1 (fever) and 97% have no ICANS1 Baseline characteristics of autoimmune disease patients treated with rese-cel RESET-Myositis RESET-SLE RESET-SSc RESET-MG Number o

13. Slide 13: Myositis: Unmet Need, Clinical Data and Commercial Opportunity

    Myositis: Unmet Need, Clinical Data and Commercial Opportunity 13

14. Slide 14: Myositis: High rates of disability & increased risk of mortality

    Myositis: High rates of disability & increased risk of mortality Highly concentrated treatment network in the US; dermatomyositis represents ~75% of this market “I find it very difficult to get up from a regular chair, I need High disease burden: disability & mortality boosters or assistance from so

15. Slide 15: Dermatomyositis (DM): Limited treatment options for ~60k U.S. patients

    Dermatomyositis (DM): Limited treatment option​s for ~60k U.S. patients Approved treatments limited to adults and require chronic use on top of immunomodulators Limited treatment options1 Eligible U.S. adult DM patients2 Adult DM patients with moderate to severe, refractory disease • Common therapie

16. Slide 16: Myositis registrational cohort – Key design elements

    Myositis registrational cohort – Key design elements Single-arm cohort including DM/ASyS patients with a primary endpoint at 16 weeks Phase 1/2 Cohorts Registrational Cohort2 DM (combined n ~6) DM & ASyS (n=17) ASyS (n ≥ 6) JDM1 • RESET-Myositis trial now enrolling registrational cohort in DM (14 p

17. Slide 17: Baseline characteristics: First 17 patients in RESET-Myositis

    Baseline characteristics: First 17 patients in RESET-Myositis All patients had active, refractory disease despite multiple medications, including IVIg and B cell-targeting therapies DM ASyS IMNM JDM N=6 N=4 N=6 N=1 Age, years, median (min, max) 57 (45, 72) 44 (26, 57) 59 (33, 64) 14 Female, n (%) 5

18. Slide 18: Efficacy data in DM and JDM patients following rese-cel infusion

    Efficacy data in DM and JDM patients following rese-cel infusion 6 of 7 patients achieved moderate or major IM-free TIS response at Week 16 which was maintained through latest follow-up Discontinued all immunomodulators TIS (N=7)† DM and JDM Major Assessment at Week 16 patients (N=7) TIS TIS Complet

19. Slide 19: CAR T may eliminate active disease & use of expensive medications

    CAR T may eliminate active disease & use of expensive medications Rese-cel safety profile facilitates outpatient administration which could allow for favorable reimbursement Cancer CAR T: Safety profile often requires inpatient infusion, affecting reimbursement Cancer patients experience early and f

20. Slide 20: RESET program designed for outpatient administration at launch

    RESET program designed for outpatient administration at launch Outpatient administration reduces administrative burden and improves patient and provider accessibility INPATIENT MODEL OUTPATIENT MODEL Limited patient beds More favorable safety profile and resource infrastructure reduces need for inpa

21. Slide 21: Rese-cel commercial model – manufacturing and COGM

    Rese-cel commercial model – manufacturing and COGM Health status of patient population and slower disease progression improve manufacturing cost efficiency In oncology, disease progress & out of specification (OOS) rates increase costs and reduce margins Late-stage oncology patients have high drop-o

22. Slide 22: Three-phase approach to rese-cel launch in myositis and beyond

    Three-phase approach to rese-cel launch in myositis and beyond1 Rese-cel safety data facilitates plan to target academic centers at launch with rapid community expansion Phase 3 Academic, Community Hospitals and Outpatient Phase 2 Clinics Academic & Community Objective: Increase patient reach Hospit

23. Slide 23: Systemic Sclerosis: Unmet Need & Clinical Data

    Systemic Sclerosis: Unmet Need & Clinical Data 23

24. Slide 24: Systemic sclerosis: Profound unmet need & limited options

    Systemic sclerosis: Profound unmet need & limited options Associated with progressive morbidity and high mortality1,2 Rare, potentially life-threatening autoimmune disease1 Eligible U.S. SSc patients6 • Characterized by progressive skin & internal organ fibrosis1 SSc patients with early, active dise

25. Slide 25: Baseline characteristics: First 15 Patients in RESET-SSc

    Baseline characteristics: First 15 Patients in RESET-SSc All patients had active, refractory disease despite multiple SSc therapies, and 12/15 had ILD Cohort Severe skin cohort§ (N=6) Organ cohort§ (N=9) All (N=15) ILD (N=12) Age, years, median (min, max) 57 (42, 66) 43 (19, 70) 54 (19, 70) 54.5 (19

26. Slide 26: Efficacy data in SSc following rese-cel infusion

    Efficacy data in SSc following rese-cel infusion After discontinuing immunomodulators, FVC improvement or stabilization was observed in most patients with ILD* FVC % predicted (Patients with ILD*; N=12)† rCRISS response (All cohorts, N=15) Discontinued all immunomodulators Proportion of patients ach

27. Slide 27: Rese-cel Manufacturing Strategy & Innovation

    Rese-cel Manufacturing Strategy & Innovation 27

28. Slide 28: Rese-cel Manufacturing Process – Commercial Readiness

    Rese-cel Manufacturing Process – Commercial Readiness Partial automation anticipated at launch with full automation planned for post-launch supply T cell collection Rese-cel manufacture (9 day) Product release Rese-cel administration apheresis cell selection QC testing and and activation cell expans

29. Slide 29: Initial automated manufacturing & translational data

    Initial automated manufacturing & translational data Cellares automation: consistent manufacturing and translational rese-cel data in 1st 2 patients vs. traditional CDMOs Viability 1 %CD45+ CD3+ %CD3+ CAR+ Vector copy number Potency (accesses T cell health) (Total T cells produced) (Total CAR-T cell

30. Slide 30: Advancing breakthrough innovations to improve scalability and costs

    Advancing breakthrough innovations to improve scalability and costs Automation plus elimination of preconditioning and apheresis could impact patient preference & experience T cell collection Rese-cel manufacture and harvest (9 day) Product release Rese-cel administration CURRENT apheresis cell sele

31. Slide 31: Rese-cel – PC-Free Data at Lowest Dose in PV and Lupus

    Rese-cel – PC-Free Data at Lowest Dose in PV and Lupus 31

32. Slide 32: Summary of rese-cel without preconditioning (PC), lowest dose cohort

    Summary of rese-cel without preconditioning (PC), lowest dose cohort1 After discontinuing all immunomodulators (IM), unanticipated activity observed without PC at lowest dose • In the RESET-PV trial, 4 refractory patients received rese-cel at the lowest dose without preconditioning and had follow-up

33. Slide 33: PC-free data in pemphigus vulgaris

    PC-free data in pemphigus vulgaris Pemphigus Vulgaris: PC-free PK and PD1 Similar CAR T expansion to PC-treated rese-cel pts with complete B cell depletion in 3 of 4 PC-free patients CAR T cell expansion Peak BAFF levels Cells/μL pg/mL Days post infusion LD Non-LD B cell depletion • PV-1M-2, PV-1M-3

34. Slide 34: Unanticipated efficacy at lowest PC-free dose supports dose escalation

    PC-free data in pemphigus vulgaris Unanticipated efficacy at lowest PC-free dose supports dose escalation Near complete resolution of clinical symptoms off all medicines in 2 of 4 patients through 6 months follow-up1 PDAI PDAI Total Activity Score Anti-DSG3 and Anti-DSG1 Titers PDAITotal TotalActivi

35. Slide 35: PC-free data in lupus

    PC-free data in lupus Lupus: PC-free rese-cel PK and PD1 Similar CAR T expansion as PC-treated patients with deep B cell depletion in 1 of 2 PC-free patients CAR T cell expansion1 Peak BAFF levels Max BAFF (pg/mL) CAR T cells/μL SLE/LN PC-free All Trials with LD Days post infusion B cell depletion1

36. Slide 36: Lupus: Unmet Need & Clinical Data

    Lupus: Unmet Need & Clinical Data 36

37. Slide 37: SLE & LN: Represent a high unmet clinical need

    SLE & LN: Represent a high unmet clinical need Increased mortality risk & negative impact on quality of life for patients with SLE & LN SLE is a chronic autoimmune condition that can affect nearly every organ system1 Eligible U.S. Non-Renal SLE & LN patients7 SLE patients with moderate to severe, re

38. Slide 38: Baseline characteristics: First 18 patients in RESET-SLE

    Baseline characteristics: First 18 patients in RESET-SLE All patients had active, refractory disease and had failed multiple B cell-targeted therapies Non-renal SLE LN​ Cohort​ (N=12) (N=6) Age, years, median (min, max) 31 (21, 44) 26 (18, 35)​ Female, n (%) 11 (92) 5 (83) Disease duration,* years,

39. Slide 39: Efficacy data in SLE following rese-cel infusion

    Efficacy data in SLE following rese-cel infusion Improvements in SLEDAI-2K and PGA over time after discontinuing immunomodulators SLEDAI-2K, non-renal SLE (N=12)*,† SLEDAI-2K, LN (N=6)* PGA (N=18)*,†,§ Discontinued all SLE Discontinued all SLE Discontinued all SLE immunomodulators‡ immunomodulators

40. Slide 40: Myasthenia Gravis: Unmet Need & Clinical Data

    Myasthenia Gravis: Unmet Need & Clinical Data 40

41. Slide 41: Myasthenia gravis: Significant disease & treatment burden

    Myasthenia gravis: Significant disease & treatment burden High impact of disease due to patient symptoms & cost burden, particularly for refractory patients Serious, chronic autoimmune neuromuscular disorder1 Eligible U.S. MG patients2 • Characterized by defective transmission at the neuromuscular G

42. Slide 42: Baseline Characteristics: 14 RESET-MG Patients

    Baseline Characteristics: 14 RESET-MG Patients All patients had active, refractory disease despite multiple immunomodulatory agents AChR Positive AChR Negative (n=8) (n=6) Age, years, mean (min, max) 54.6 (41, 65) 53.3 (37, 70) Female, n (%) 3 (37.5%) 6 (100.0%) Time from diagnosis to screening, yea

43. Slide 43: Efficacy Data in AChR-Positive Patients Following Rese-cel Infusion

    Efficacy Data in AChR-Positive Patients Following Rese-cel Infusion1 6 of 8 AChR-positive patients showed clinically meaningful improvements on the MG-ADL scale while 2 patients required rescue medications, as of latest follow-up MG-ADL* QMG* Discontinued all immunomodulators Discontinued all immuno

44. Slide 44: Efficacy Data in AChR-Negative Patients Following Rese-cel Infusion

    Efficacy Data in AChR-Negative Patients Following Rese-cel Infusion1 4 of 6 AChR-negative patients showed clinically meaningful improvements on the MG-ADL scale while 2 patients received rescue medications, as of latest follow-up MG-ADL* QMG* Discontinued all immunomodulators Discontinued all immuno

45. Slide 45: Corporate Summary

    Corporate Summary Cabaletta Bio’

46. Slide 46: Cabaletta Bio leadership

    Cabaletta Bio leadership Track record of operational success evaluating & developing novel cell therapy candidates in autoimmunity LEADERSHIP TEAM Steven Nichtberger, M.D. Samik Basu, M.D. Gwendolyn Binder, Ph.D. David J. Chang, M.D., M.P.H., FACR Arun Das, M.D. Steve Gavel President, CEO & Chairman

47. Slide 47: Immune reset with a single infusion and a favorable safety profile

    Immune reset with a single infusion and a favorable safety profile Beyond myositis and scleroderma, advancing innovation with PC-free rese-cel & industrialized automated mfg Transformative Value Elimination of PC Automated Manufacturing Proposition ▪ Expands the market ▪ Minimizes capital investment

48. Slide 48: Appendix

    Appendix Cabaletta Bio’

49. Slide 49: Myositis outcomes captured through validated composite endpoint

    Myositis outcomes captured through validated composite endpoint TIS is a composite tool measuring a patient’s relative improvement from their baseline Total improvement score (TIS) components 100 Illustrative patient- specific TIS ceiling for more severe Manual Muscle Testing disease (MMT8) 80 Major

50. Slide 50: Corporate Presentation

    Corporate Presentation SEPTEMBER 2026 © 2026 Cabaletta Bio. All rights reserved.

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