Cabaletta Bio — Third Quarter 2026 Earnings Summary

Financial Performance:

• Research and development expenses were $47.1 million for the three months ended September 30, 2026, compared to $39.8 million in the same period of 2025.
• General and administrative expenses were $7.6 million for the three months ended September 30, 2026, compared to $6.8 million in the same period of 2025.
• Net loss was $53.1 million for the three months ended September 30, 2026, compared to $44.9 million in the same period of 2025.
• Net loss per share (basic and diluted) was $0.28 for the three months ended September 30, 2026, compared to $0.44 in the same period of 2025.
• Cash and cash equivalents totaled $299.4 million as of September 30, 2026, including approximately $115.0 million from exercises of common stock warrants between July 1, 2026, and September 12, 2026.
• Total operating expenses were $54.7 million for the three months ended September 30, 2026, compared to $46.6 million in the same period of 2025.

Guidance and Future Outlook:

• Registrational topline results for the RESET-Myositis adult cohort are anticipated in the second half of 2027, supporting a Biologics License Application (BLA) submission in the first quarter of 2028.
• The company expects to include juvenile dermatomyositis data in the 1Q28 BLA submission to support a potential pediatric indication and eligibility for a Priority Review Voucher (PRV).
• Operational runway is extended into the first quarter of 2028 based on the current cash position.
• Go-forward clinical development plans regarding the preconditioning-free (PC-free) program are expected to be announced in the first half of 2027.
• Cabaletta plans to present one-year durability data from the complete Phase 1/2 dermatomyositis cohort at ACR Convergence 2026.

Business Segments and Product Lines:

• The registrational, 17-patient dermatomyositis (DM) and antisynthetase syndrome (ASyS) cohort for rese-cel is expected to deliver topline results in 2H27.
• The registrational RESET-SSc cohort in systemic sclerosis patients with interstitial lung disease has been initiated and is open for enrollment, with a primary endpoint measuring improvement in forced vital capacity (FVC).
• The Phase 1/2 juvenile myositis cohort is open for enrollment and incorporates an outpatient dosing option.
• RESET-SLE, RESET-MG, and RESET-PV programs are advancing with higher-dose, preconditioning-free (PC-free) rese-cel trials open for enrollment.
• Recent data presented at the European Society of Gene and Cell Therapy 2026 showed that five systemic sclerosis patients with interstitial lung disease achieved a mean percent-predicted FVC improvement of approximately 9% at one year.
• Data from 14 RESET-MG patients treated with rese-cel and preconditioning showed no cytokine release syndrome in 12 patients and no immune effector cell-associated neurotoxicity syndrome.

Market and Competitive Landscape:

• Systemic sclerosis patients with interstitial lung disease represent a population with one of the highest mortality rates among rheumatological conditions and currently have no FDA-approved therapies to improve lung function.
• Enrollment and screening activity for the registrational adult myositis study have increased following a slower period in Q3 2026 attributed to patient and physician caution regarding safety events in the broader field.
• Cabaletta is advancing innovations to broaden and deepen the treatment potential of rese-cel across autoimmune diseases.

Risks and Challenges:

• Clinical trial results, including signs of biologic activity or clinical response, may not be predictive of long-term results or translate across programs.
• Risks include delays in clinical trial site activation, enrollment rates lower than expected, and delays related to the assessment of clinical trial results.
• Unexpected safety or efficacy data observed during studies could impact development plans.
• The company faces risks related to regulatory filings, potential clearance, and the ability to demonstrate sufficient evidence of safety, efficacy, and tolerability.
• Volatile market and economic conditions and public health crises could impact the company's operations.

Management Commentary and Tone:

• CEO Steven Nichtberger expressed encouragement regarding the favorable benefit-risk profile of rese-cel, citing deliberate design choices prioritizing patient safety.
• Management noted increased enrollment activity in the registrational adult myositis study after a slower period in Q3 2026.
• The tone highlighted excitement regarding progress in the juvenile dermatomyositis program and the initiation of the second registrational study in systemic sclerosis.
• Management emphasized the plan to include multi-year Phase 1/2 myositis durability data in the planned BLA submission based on a recent Type B regulatory interaction with the FDA.

Other Key Points:

• Cabaletta will host an industry-supported Innovation Theater at ACR Convergence 2026 titled "Designed for Autoimmunity: Rese-cel and the RESET Clinical Program."
• The company expects to have three-year durability data from some Phase 1/2 patients at the time of potential launch.
• The RESET-SSc cohort focuses on patients with interstitial lung disease and utilizes an outpatient dosing option.
• Total assets increased to $336.5 million as of September 30, 2026, compared to $165.1 million as of December 31, 2025.
• Total stockholders' equity increased to $283.9 million as of September 30, 2026, compared to $112.1 million as of December 31, 2025.