---
schema_version: "secwatch.filing_event.v1"
accession: "0001558370-23-015014"
form_type: "8-K"
ticker: "MBIO"
cik: "0001680048"
company_name: "MUSTANG BIO, INC."
filed_at: "2023-08-16T23:59:59+00:00"
generated_at: "2026-06-11T08:33:30.157567+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Mustang Bio reports 4 of 4 indolent lymphoma patients respond to MB-106 CAR T; dose escalation approved

## Summary
- Clinical responses in 4 of 4 indolent lymphoma patients at starting dose 3.3x10^6 CAR T cells/kg; 2 follicular lymphoma patients achieved CR.
- Safety Review Committee unanimously approved dose escalation to 1.0x10^7 CAR T cells/kg; only Grade 1 CRS reported.
- Fred Hutch trial (n=20 FL) shows 95% ORR, 80% CR; first patient sustained CR >3 years.
- Waldenstrom macroglobulinemia cohort (n=6): 2 CR, one ongoing >22 months; no CRS/ICANS >Grade 2.
- Pivotal Phase 2 for WM to start mid-2024, top-line data mid-2026; end-of-Phase 1 FDA meeting expected end of 2023.

## SEC filing metadata
- accession: 0001558370-23-015014
- form_type: 8-K
- ticker: MBIO
- cik: 0001680048
- company_name: MUSTANG BIO, INC.
- filed_at: 2023-08-16T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1680048/000155837023015014/0001558370-23-015014-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1680048/000155837023015014/tmb-20230816x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001558370-23-015014
- JSON: https://secwatch.observer/filing/0001558370-23-015014.json
- Plain text: https://secwatch.observer/filing/0001558370-23-015014.txt

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