---
schema_version: "secwatch.filing_event.v1"
accession: "0001619856-23-000050"
form_type: "8-K"
ticker: "CRBU"
cik: "0001619856"
company_name: "Caribou Biosciences, Inc."
filed_at: "2023-03-29T23:59:59+00:00"
generated_at: "2026-06-17T10:28:35.331001+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Caribou Biosciences doses first patient in Phase 1 trial of CB-011 for multiple myeloma

## Summary
- First patient dosed with CB-011 at dose level 1 (50x10^6 CAR-T cells) in CaMMouflage Phase 1 trial for relapsed/refractory multiple myeloma.
- CB-011 is an allogeneic anti-BCMA CAR-T cell therapy with immune cloaking via B2M removal and B2M-HLA-E transgene insertion.
- Trial is open-label, 3+3 dose escalation (Part A) followed by dose expansion (Part B); excludes prior CAR-T or BCMA therapy within 3 months.
- CB-011 is Caribou's second allogeneic CAR-T program to enter the clinic.
- Company plans to continue enrollment at dose level 1 and provide dose clearance updates.

## SEC filing metadata
- accession: 0001619856-23-000050
- form_type: 8-K
- ticker: CRBU
- cik: 0001619856
- company_name: Caribou Biosciences, Inc.
- filed_at: 2023-03-29T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1619856/000161985623000050/0001619856-23-000050-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1619856/000161985623000050/crbu-20230329.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001619856-23-000050
- JSON: https://secwatch.observer/filing/0001619856-23-000050.json
- Plain text: https://secwatch.observer/filing/0001619856-23-000050.txt

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