---
schema_version: "secwatch.filing_event.v1"
accession: "0001619856-23-000134"
form_type: "8-K"
ticker: "CRBU"
cik: "0001619856"
company_name: "Caribou Biosciences, Inc."
filed_at: "2023-12-12T23:59:59+00:00"
generated_at: "2026-06-07T14:13:44.750648+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Caribou reaches FDA alignment on CB-010 phase 3 trial design; CMO to depart Dec 31

## Summary
- FDA accepts comparator arm of platinum-based immunochemotherapy + HDCT + ASCT for CB-010 phase 3 in 2L r/r LBCL.
- Phase 3 pivotal trial initiation planned by year-end 2024; RP2D and initial dose expansion data expected Q2 2024.
- CB-010 is first allogeneic anti-CD19 CAR-T in 2L LBCL; granted RMAT, Fast Track, and Orphan Drug designations.
- Chief Medical Officer Syed Rizvi to leave effective Dec 31, 2023; separation agreement with release required.
- Search underway for new CMO; ANTLER dose expansion enrollment continues with 22 U.S. sites and 1 in Australia active.

## SEC filing metadata
- accession: 0001619856-23-000134
- form_type: 8-K
- ticker: CRBU
- cik: 0001619856
- company_name: Caribou Biosciences, Inc.
- filed_at: 2023-12-12T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 5.02, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1619856/000161985623000134/0001619856-23-000134-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1619856/000161985623000134/crbu-20231211.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001619856-23-000134
- JSON: https://secwatch.observer/filing/0001619856-23-000134.json
- Plain text: https://secwatch.observer/filing/0001619856-23-000134.txt

## Key facts
- Executive change
  Syed Rizvi departed as Chief Medical Officer at Caribou Biosciences, Inc..
  - Action: leaving
  - Role: Chief Medical Officer
  source text: Syed Rizvi, M.D., the Chief Medical Officer of Caribou Biosciences, Inc. (the “Company”), will be leaving the Company effective December 31, 2023.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1619856/000161985623000134/0001619856-23-000134-index.htm

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