---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-146067"
form_type: "8-K"
ticker: "CABA"
cik: "0001759138"
company_name: "Cabaletta Bio, Inc."
filed_at: "2023-05-16T23:59:59+00:00"
generated_at: "2026-06-14T23:53:53.318729+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# FDA clears CABA-201 IND for Phase 1/2 myositis study; DesCAARTes updates provided

## Summary
- FDA cleared second IND for CABA-201 (CD19-CAR T) for Phase 1/2 trial in active myositis (DM, ASyS, IMNM) at 1x10^6 cells/kg dose.
- Company plans to enroll 18 patients in three parallel cohorts (6 each) for dermatomyositis, anti-synthetase syndrome, and immune-mediated necrotizing myopathy.
- DesCAARTes trial: modest persistence increase in first two patients in IVIg+Cy combination cohort; new fludarabine+IVIg+Cy cohort to be initiated.
- MusCAARTes study timelines being evaluated based on emerging DesCAARTes data.
- Myositis subtypes targeted affect ~66,000 patients in the US; current treatments often refractory.

## SEC filing metadata
- accession: 0001193125-23-146067
- form_type: 8-K
- ticker: CABA
- cik: 0001759138
- company_name: Cabaletta Bio, Inc.
- filed_at: 2023-05-16T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1759138/000119312523146067/0001193125-23-146067-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1759138/000119312523146067/d492544d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-146067
- JSON: https://secwatch.observer/filing/0001193125-23-146067.json
- Plain text: https://secwatch.observer/filing/0001193125-23-146067.txt

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