---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-235533"
form_type: "8-K"
ticker: "CABA"
cik: "0001759138"
company_name: "Cabaletta Bio, Inc."
filed_at: "2025-10-09T23:59:59+00:00"
generated_at: "2026-05-17T04:13:31.215119+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Cabaletta Bio presents first rese-cel data without preconditioning at ESGCT 2025

## Summary
- Rese-cel without preconditioning achieved complete B cell depletion in two of three PV patients, with rapid autoantibody reduction and near-complete symptom resolution.
- PDAI activity scores improved from baseline to latest follow-up: Patient 1 (24 to 10 at 4 mo), Patient 2 (83 to 3 at 3 mo), Patient 3 (22 to 2 at 1 mo).
- All three patients remained off immunomodulators since infusion and are off or tapering steroids as of the September 11, 2025 data cut-off.
- CAR T cell expansion kinetics without preconditioning were similar to those observed across 30+ patients dosed with preconditioning in other RESET trials.
- No ICANS was reported; one patient had transient grade 1 CRS, and another required steroids for a disease flare that later tapered below baseline.

## SEC filing metadata
- accession: 0001193125-25-235533
- form_type: 8-K
- ticker: CABA
- cik: 0001759138
- company_name: Cabaletta Bio, Inc.
- filed_at: 2025-10-09T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1759138/000119312525235533/0001193125-25-235533-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1759138/000119312525235533/caba-20251009.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-235533
- JSON: https://secwatch.observer/filing/0001193125-25-235533.json
- Plain text: https://secwatch.observer/filing/0001193125-25-235533.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.