Cabaletta Bio : Corporate Presentation

Published: 2026-05-04 06:59:09 ET CABA

Published on 05/04/2026 at 06:59 am EDT

Corporate Presentation

MAY 2026

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

Rese-cel1: Delivering on the promise of CD19-CAR T in autoimmunity

Preconditioning (PC) free clinical data & automated manufacturing data anticipated throughout 2026

Rese-cel data: immunomodulator-free efficacy with a favorable safety profile using a single weight-based dose

Complete phase 1/2 data expected in systemic sclerosis and lupus in 1H26; myasthenia gravis data presented at AAN

Primary endpoint: moderate TIS off immunomodulators & on no or low dose steroids3 at 16 weeks

All phase 1/2 patients with sufficient f/u who would have met inclusion criteria met the registrational primary endpoint4

95% - No CRS (~67%) or Grade 1 CRS (~28% - fever); 95% - No ICANS5

Data at ASGCT (May 14); next higher dose in RESET-PV and initial dose in RESET-SLE anticipated throughout 2026

Initial translational data at ASGCT (May 14); commercial supply agreement includes among lowest COGS in industry

$150mn raise extends runway into mid-27 including 2026 advances in PC free program, automated scalable manufacturing, progress to BLA submission in myositis next year and initiation of second pivotal indication

BLA - biologics license application; f/u - follow-up; PV - pemphigus vulgaris; SLE - systemic lupus erythematosus; TIS - total improvement score.

resecabtagene autoleucel; CABA-201

Solimani, Farzan, et al. "Clinical progress of engineered cellular immunotherapies for autoimmunity." Nature Biotechnology (2026): 1-16.

Low dose steroids is defined as 50% reduction from baseline or ≤7.5 mg/day.

Transformative value proposition with PC elimination & automation

Removing PC should expand access while automated manufacturing should reduce COGS & increase scale

Elimination of PC Automated Manufacturing

Transformative Value Proposition

Expands the market

Catalyzes outpatient use

Reduces resource utilization

Improves patient and provider

experience

Minimal capital investment

Differentiated product profile

Typical 'biologic' margins

Potential to address larger autoimmune indications including T1D, UC and RA

Scalability to produce thousands of patient runs per year

Substantially reduced COGS

Facilitates global expansion

PV: PC free rese-cel data including longer-term follow up at the initial dose SLE: PC free rese-cel data including early data at the initial dose Initial clinical experience with rese-cel manufactured by Cellares

Longer-term PC free rese-cel data from the PV & SLE dose cohorts and from patients receiving rese-cel manufactured by Cellares

Innovative clinical strategy to support accelerated regulatory path

SLE registrational design in hand; SSc pivotal design anticipated 1H26 and MG anticipated mid-2026

Program

Trial

Preclinical

Phase 1/2

Registrational

RESET-Myositis®

RMAT

Dermatomyositis / Antisynthetase syndrome Immune-mediated necrotizing myopathy Juvenile Myositis

FTD

Rese-cel

(CABA-201)

4-1BB CD19-CAR T

RESET-SLE

RESET-SSc

RESET-MG RESET-PV®

RMAT

Lupus Nephritis Non-Renal SLE Skin + Organ Cohort Skin Cohort

AChR-Ab pos. gMG AChR-Ab neg. gMG Pemphigus vulgaris

Rheumatology1 Neurology Dermatology

Contains cohort(s) without preconditioning

Pediatric Indication

Complete Phase 1/2 data expected in SLE/LN and SSc

RESET - REstoring SElf-Tolerance; Ab - Antibody; AChR - Acetylcholine receptor; gMG - Generalized myasthenia gravis; PV - Pemphigus vulgaris; SLE - Systemic lupus erythematosus; SSc - Systemic sclerosis

1. Myositis patients can also be treated by neurologists or dermatologists; lupus nephritis patients can also be treated by nephrologists.

FDA Fast Track Designation received in dermatomyositis, SLE and lupus nephritis, systemic sclerosis, generalized myasthenia gravis and multiple sclerosis. 6

Rese-cel:

Clinical Profile and Commercial Opportunity

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

No PC Cohorts

No PC only

Typical onset middle age Only FDA-approved

therapy is IVIg in DM

Three-fold increased mortality due to lung & cardiac involvement

Myositis

Affects young women &

people of color

~30-40% with lupus nephritis, which carries

~25% risk of death or ESRD within 10y

SLE/LN

Middle age onset

common

Progressive skin & organ fibrosis with lung, cardiac, renal damage

Average survival of 12y

SSc

Bimodal age of onset

Profound weakness that can be disabling

Risk for myasthenic crises, with respiratory failure

gMG

Pure autoantibody & B-cell mediated autoimmune disease

Characterized by painful blisters & erosions

~80k

~320k

~90k ~100k ~15k

Rheum Neuro Derm

SLE - Systemic lupus erythematosus; DM - Dermatomyositis; SSc - Systemic sclerosis; gMG - Generalized myasthenia gravis; PC - Preconditioning; ESRD - End-stage renal 8

disease; PV - pemphigus vulgaris

Rese-cel: CD19-CAR T specifically designed for autoimmunity

Rese-cel binder with similar in vitro & in vivo activity to construct used in academic studies in autoimmunity1,3

BB costimulatory domain with fully human binder

Binder with similar affinity & biologic activity to academic FMC63 binder while binding to the same epitopes1,2

Same weight-based dose as in academic studies

Potential to provide immune reset based on

clinical and translational data5

Patients treated with rese-cel have shown compelling clinical responses with safety data that supports outpatient use for autoimmune patients6

Rese-cel product design & clinical / translational data

Rese-cel4

Fully human anti-CD19 binder

Peng BJ, et al. Mol Ther Methods Clin Dev. 2024;32(2):101267.

Dai, Zhenyu, et al. "Development and functional characterization of novel fully human anti-CD19 chimeric antigen receptors for T-cell therapy." Journal of Cellular Physiology 236.8 (2021): 5832-5847.

Müller, Fabian, et al. "CD19 CAR T-Cell Therapy in Autoimmune Disease-A Case Series with Follow-up." New England Journal of Medicine 390.8 (2024): 687-700.

Maschan, Michael, et al. "Multiple site place-of-care manufactured anti-CD19 CAR-T cells induce high remission rates in B-cell malignancy patients." Nature Communications 12, 7200 (2021)

Transmembrane domain in rese-cel is CD8α vs. TNFRSF19 (Troy) utilized in the academic construct. The two transmembrane domains have not been shown to have a significant difference in function or IFN-γ production in preclinical studies. The CD8α transmembrane domain is employed in tisagenlecleucel.

Volkov, Jenell, et al. "Case study of CD19 CAR T therapy in a subject with immune-mediate necrotizing myopathy treated in the RESET-Myositis phase I/II trial." Molecular Therapy 32.11 (2024): 3821-3828.

Abstract 1733: Safety and Efficacy of CABA-201, a Fully Human, Autologous 4-1BB Anti-CD19 CAR T Cell Therapy in Patients with Immune-Mediated Necrotizing Myopathy and Systemic Lupus 9

Erythematosus from the RESET-MyositisTM and RESET-SLETM Clinical Trials. ACR 2024.

RESETTM clinical trials have consistent design principles1

Leukapheresis and rese-cel production

Preconditioning

Single infusion

of rese-cel

Primary endpoint: Incidence and severity of AEs

Many of the RESET trials share common elements of preconditioning, dose, and study design

Screening

Day -5 to Day -3

Day 1

Day 29

Study follow-up through Year 3†

Additional Endpoints

•

Discontinuation of all immunomodulatory agents

Clinical efficacy measuring:

Drug-free responses

Validated endpoints

•

PK/PD analysis:

Rese-cel expansion

B cell depletion

Peak BAFF levels

B cell repopulation

Adverse events & safety

Biomarker analysis, including

autoantibody levels

Weight-based

dosing

1×106 cells/kg

FLU 25 mg/m2 x 3 days

CY 1000 mg/m2 x 1 day

(if required)

T cells isolated from patient's own PBMCs (autologous CAR T)

†Follow up period encompasses at least 15 years in total, ed to regulatory guidance for CAR T cell therapies.

AE, adverse event; CABA, Cabaletta Approach to B cell Ablation; FLU, fludarabine; CY, cyclophosphamide; PBMC, peripheral blood mononuclear cell; PD, pharmacodynamics; PK, pharmacokinetics; RESET,

Rese-cel expansion & B cell kinetics across indications*

Peak rese-cel expansion and transient peripheral B cell depletion occurred within ~2 weeks post infusion

RESET-Myositis

RESET-SLE

RESET-SSc

RESET-MG

B Cell Kinetics

Rese-cel Pharmacokinetics* Rese-cel Pharmacokinetics** Rese-cel Pharmacokinetics

†

B Cell Kinetics

Rese-cel Pharmacokinetics

‡

B Cell Kinetics

Peripheral B cells begin repopulating ~2 to 3 months after rese-cel in patients with sufficient follow-up*

*All data is as of 11 Sep, 2025, except DM-3 which includes Week 24 data as of 08 Oct 2025.

**LN-1 had prolonged rese-cel detection due to TCR activation that corresponded to longer time to B cell repopulation. LN-4: follow up ongoing

† DM-3 rese-cel PK at Week 20 was artifactually elevated due to low circulating lymphocyte counts.

‡ Reduced rese-cel expansion observed in AChR-pos-1 may be attributed to patient's continued use of azathioprine, a prohibited medication, until day of infusion (Day 1).

ASyS, antisynthetase syndrome; CAR, chimeric antigen receptor; DM, dermatomyositis; IMNM, immune-mediated necrotizing myopathy; LN, lupus nephritis; rese-cel, resecabtagene autoleucel; RESET,

Demographics & CRS/ICANS in 1st 40 rese-cel patients by indication

Across 4 RESET

studies, 95% of patients with no CRS or Grade 1 CRS (fever) and 95% with no ICANS1

Baseline characteristics of autoimmune disease patients treated with rese-cel

RESET-Myositis

RESET-SLE

RESET-SSc

RESET-MG

Number of patients

Age, years, mean (SD)

51.7 (14.6)

30.4 (7.6)

53.1 (12.3)

57.5 (9.8)

Sex, % female

53.3

80.0

66.7

Duration of disease, years, mean (SD)

5.4 (3.7)

9.8 (5.0)

2.2 (1.3)

5.1 (5.3)

Incidence, severity and onset of CRS and ICANS in the 1st 28 days in patients treated with rese-cel

RESET-Myositis

RESET-SLE

RESET-SSc

RESET-MG

Total

CRS‡, n (%)

5 (33.3)

3 (30.0)

4 (44.4)

1 (16.7)

13 (32.5% CRS)

CRS Grade 1, n (%)

5 (33.3)

3 (30.0)

3 (33.3)

0 (0.0)

11 (27.5% G1 CRS)

CRS Grade 2, n (%)

1 (11.1)

1 (16.7)

2 (5% G2 CRS)

Time to CRS onset, days* (mean)

7.4

7.3

8.5

7.0

7.7 days

CRS duration† , days (mean)

4.6

3.0

2.0

3.5 days

ICANS‡ n (%) (Grade)

1 (10) (G4)

1 (11.1) (G3)

2 (5% ICANS)

Time to ICANS onset. days (mean)

9.0

8.0

8.5 days

ICANS duration, days (mean)

3.0

3.0 days

*Days relative to rese-cel infusion.

†Events occurring within 7 days of each other are considered as 1 episode. IMNM-3 CRS duration includes preceding event of fever which was consistent with CRS definition.

CAR T may eliminate active disease & use of expensive medications

Rese-cel safety profile permits outpatient administration which could facilitate favorable reimbursement

Cancer patients experience early and frequent CRS/ICANS following CAR T therapy, which increases inpatient admissions and shifts Medicare reimbursement to the DRG system.

Majority of oncology patients treated with CAR T therapy experience CRS within first 5 days post-infusion1

Many cancer patients are insured under Medicare, which has inpatient DRG-018 reimbursement

Rese-cel: Safety profile facilitates outpatient infusion, which could favorably impact reimbursement

Commercial

Myositis & SSc patients often commercially insured (60%-75%)2,3

CRS less frequent & severe,

delayed onset potential

outpatient administration

Outpatient CAR T

infrastructure exists at many centers

Outpatient administration

supports viable Part B Medicare payments

RESET clinical site

footprint can be leveraged to generate early adopters

Ferreri, Christopher J., and Manisha Bhutani. "Mechanisms and management of CAR T toxicity." Frontiers in Oncology 14 (2024): 1396490.

Smoyer-Tomic KE, et al. BMC Musculoskelet. Disord. 2012 Jun 15;13:103. doi: 10.1186/1471-2474-13-103.

RESET program designed for outpatient administration at launch

Outpatient administration reduces administrative burden and improves patient and provider accessibility

INPATIENT MODEL

Limited patient beds

and resource infrastructure

Increases inpatient resource pressure:

↑ total cost of care, human resource

and bed space demands

Reduces eligible patients treated

OUTPATIENT MODEL

More favorable safety profile

reduces need for inpatient admission

Reduces use of hospital resources;

Increases throughput

Reduces conflicts with cancer patient

use of in-patient beds

Rese-cel commercial model - manufacturing and COGM

Health status of patient population and slower disease progression improve manufacturing cost efficiency

Late-stage oncology patients have high drop-off rate due to rapid disease progression and compromised T cell fitness, leading to higher manufacturing OOS rates1,2,3

Increased OOS rates; ↑ COGM

+ ↓ revenue since out of spec

products not reimbursed

Disease progression reduces revenue capture because unused product not reimbursed

Reduced eligible patients, resulting in economies of scale not being achieved

Manufacturing capacity constraints

delayed commercial ramp-up

In autoimmunity, healthier patients & fully automated rese-cel mfg, should support lower COGM

Autoimmune patients are not heavily pretreated with chemotherapy more fit immune cells that support reliable manufacture, reducing COGM

Autoimmune patients rarely progress as rapidly as cancer patients more reliable revenue realization for manufactured product

Building manufacturing capacity at CDMOs to support successful launch; Cellares automation has the potential to facilitate post-approval expansion

COGM - Cost of goods manufactured

U.S. Food and Drug Administration. Kymriah (tisagenlecleucel) Prescribing Information. Revised 2025, U.S. Food and Drug Administration, https://www.fda.gov/media/107296/download

U.S. Food and Drug Administration. Breyanzi (lisocabtagene maraleucel) Prescribing Information. Revised 2025, U.S. Food and Drug Administration, https://www.fda.gov/media/145711/download

Myositis: Unmet Need & Clinical Data

Myositis: High rates of disability & increased risk of mortality

Highly concentrated treatment network in the US; dermatomyositis represents ~75% of this market

High disease burden: disability & mortality

Typical patient is a middle-aged female who experiences muscle weakness, fatigue, pain, shortness of breath and difficulty swallowing

Moderate to severe disability (40% to 65%)1

Assisted walking devices (18% to 38%)1

The risk of mortality is ~3 times higher than the general population, primarily due to cancer and lung & cardiac complications2

~20% mortality < 5 years with standard immunosuppressive treatment3

"John"

"I find it very difficult to get up from a regular chair, I need boosters or assistance from somebody else. Walking, my gait has really suffered. My stability walking has suffered as well, and I can't lift anything more than five or eight pounds. So doing stuff is difficult. Bending down is very difficult. I can't get up from the floor if I fall."

61-year-old male with ASyS4

"It just affected every aspect of my life. Just work, family, social life, own wellbeing. It just pours into everything else with that."

~10 yrs since diagnosis

"Erica"

44-year-old female with DM4

~60,000 pts5,6

Dermatomyositis (DM)

~15,000 pts7,8

Anti-synthetase syndrome (ASyS)

~7,500 pts5,9

Immune-mediated necrotizing myopathy (IMNM)

Subtype prevalence in the U.S.

~2.5 yrs since diagnosis

Opinc AH, Brzezinska OE, Makowska JS. Disability in idiopathic inflammatory myopathies: questionnaire-based study. Rheumatol Int. 2019;39(7):1213-1220.

Marie I. Morbidity and mortality in adult polymyositis and dermatomyositis. Curr Rheumatol Rep. 2012;14(3):275-285.

Schiopu E, Phillips K, MacDonald PM, Crofford LJ, Somers EC. Predictors of survival in a cohort of patients with polymyositis and dermatomyositis: effect of corticosteroids, methotrexate and azathioprine. Arthritis Res Ther. 2012;14(1):R22.

Myositis: Limited treatment options for ~80k U.S. patients

IVIg is the only approved therapy (only for patients with the adult dermatomyositis subtype)

Myositis patients with moderate to severe, refractory disease potentially eligible for rese-cel

(per analysis of quantitative research with ~240 myositis-treating physicians)

~16k to 20k

U.S. myositis patients

potentially eligible for rese-cel

~80k myositis patients

Eligible U.S. myositis patients2

Autoimmune disease with B cells component

Idiopathic inflammatory myopathies (IIMs, or myositis) are a group of autoimmune diseases characterized by inflammation and muscle weakness

Limited treatment options1

Common therapies: steroids plus an immunomodulator (i.e. methotrexate, azathioprine, mycophenolate, rituximab)

IVIg (intravenous immunoglobulin), the only FDA-approved

therapy, is approved in adult dermatomyositis

Therapies can carry potential long-term side effects such as serious infections and organ damage

Despite existing therapies, disease is often refractory

Two therapies in Phase 3 development, Brepocitinib and Vyvgart®, demonstrated improvement with chronic administration added onto existing immunomodulatory medications

Myositis registrational cohort - Key design elements

Single-arm cohort including DM/ASyS patients with a primary endpoint at 16 weeks

Initial Phase 1/2 Cohorts1 Registrational Cohort2

DM & ASyS (n=17)

ASyS

(combined n ~6)

•

Expansion of current RESET-Myositis trial to include registrational cohort in DM / ASyS (~60k / ~15k US patients)

•

Primary Endpoint: Moderate or Major TIS response @ Week 16 off all immunomodulators and off or on low-dose3 steroids

•

Expanded trial to 17 patients to ensure approximately 14 DM patients can enroll based on natural U.S. prevalence estimates

•

Confirmed current dose of 1 million cells/kg in a single infusion

•

Safety database ~100 autoimmune patients at ≥1-month of follow-up (with at least 35 myositis patients)

~70% of the safety database already enrolled across the RESET clinical development program4

Registrational trial initiated with planned 2027 BLA submission

TIS, total improvement score.

Pediatric submission based on data available at the time of adult submission from ongoing Ph 1/2 study (no new study) to support pediatric label claim

Size of myositis registrational cohort based on key statistical parameters and estimated background remission rate in myositis.

Baseline characteristics: First 13 patients in RESET-Myositis*

All patients had active, refractory disease despite multiple immunomodulatory agents, including IVIg

DM N=4

ASyS N=2

IMNM N=6

JIIM N=1

Mean age, years (min, max)

~58 (45, 72)

~44 (39, 48)

~55 (33, 64)

Female, n (%)

3 (75)

1 (50)

1 (17)

1 (100)

Years since diagnosis, mean (min, max)

3.0 (2.0, 3.6)

9.2 (3.6, 14.8)

4.5 (1.4, 8.8)

8.5

Myositis-specific

autoantibody

50% TIF1-γ

25% NXP, 25% SAE

100% Jo-1

67% HMGCR

33% SRP

NXP-2

Baseline disease activity†

Mean MMT-8 Median CK, U/L Mean CDASI-A

109.6

40.0

129.5

311.5

N/A

122.0

2214.5

N/A

134.0

176.0

N/A

Prior RTX‡ Prior IVIg‡

75%

100%

50%

83%

100%

Therapies at Screening

Systemic GCs

≤2 IMs

≥3 IMs

75%

50%

100%

50%

67%

100%

*As of 11 Sep, 2025.

†Baseline disease activity = activity before preconditioning.

‡Reflects any exposure to RTX and IVIg prior or at time of study entry. RTX is not allowed within approximately 6 months of Screening.

ASyS, antisynthetase syndrome; CDASI-A, Cutaneous Dermatomyositis Disease Area and Severity Index - Activity; CK, creatine kinase; DM, dermatomyositis; GC, glucocorticoid; HMGCR, 3-hydroxy-3-methylglutaryl-coenzyme A reductase; IM, immunomodulatory medication; IMNM, immune-mediated necrotizing myopathy; IVIg, intravenous immunoglobulin; JIIM, juvenile idiopathic inflammatory myopathy;

MMT-8, manual muscle testing 8; NXP, nuclear matrix protein; N/A, not applicable; RESET, REstoring SElf-Tolerance; RTX, rituximab; SAE, small ubiquitin-like modifier activating enzyme; SRP, signal

recognition particle; TIF1, transcription intermediary factor 1; U/L, units per liter. 20

Disclaimer

Cabaletta Bio Inc. published this content on May 04, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on May 04, 2026 at 10:58 UTC.