---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-191895"
form_type: "8-K"
ticker: "CABA"
cik: "0001759138"
company_name: "Cabaletta Bio, Inc."
filed_at: "2023-07-24T23:59:59+00:00"
generated_at: "2026-06-13T04:22:02.248608+00:00"
event_type: "leadership"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Cabaletta appoints ex-Kite Pharma CCO Shawn Tomasello to board; updates DSG3-CAART data

## Summary
- Shawn Tomasello, former Kite Pharma CCO, appointed to board effective July 21, 2023.
- Tomasello granted option for 44,000 shares at $13.48, vesting quarterly over three years.
- DSG3-CAART combination sub-study shows modestly increased persistence with cyclophosphamide pretreatment.
- New DSG3-CAART cohort initiated adding fludarabine to regimen to improve engraftment.
- Company reiterates guidance for CABA-201 3-month clinical data by first half of 2024.

## SEC filing metadata
- accession: 0001193125-23-191895
- form_type: 8-K
- ticker: CABA
- cik: 0001759138
- company_name: Cabaletta Bio, Inc.
- filed_at: 2023-07-24T23:59:59+00:00
- event_type: leadership
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 5.02, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1759138/000119312523191895/0001193125-23-191895-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1759138/000119312523191895/d504778d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-191895
- JSON: https://secwatch.observer/filing/0001193125-23-191895.json
- Plain text: https://secwatch.observer/filing/0001193125-23-191895.txt

## Key facts
- Executive change
  Shawn Tomasello was appointed as Director at Cabaletta Bio, Inc..
  - Action: appointed
  - Role: Director
  source text: On July 21, 2023, upon the recommendation of its Nominating and Corporate Governance Committee (the “NCG Committee”), the Board of Directors (the “Board”) of Cabaletta Bio, Inc. (the “Company”) appointed Shawn Tomasello to join the Board, effective as of July 21, 2023 (the “Effective Date”), to fill the newly created vacancy on the Board resulting from an increase in the size of the Board from five (5) to six (6) directors.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1759138/000119312523191895/0001193125-23-191895-index.htm

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