---
schema_version: "secwatch.filing_event.v1"
accession: "0001619856-23-000138"
form_type: "8-K"
ticker: "CRBU"
cik: "0001619856"
company_name: "Caribou Biosciences, Inc."
filed_at: "2023-12-22T23:59:59+00:00"
generated_at: "2026-06-07T07:56:14.139347+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Caribou Biosciences CMO Syed Rizvi to leave Dec 31, 2023; severance terms set

## Summary
- Dr. Rizvi's departure effective Dec 31, 2023; previously announced Dec 12, 2023.
- Separation agreement provides 9 months base salary and COBRA premium reimbursement.
- 15,000 RSUs will vest on Jan 18, 2024 as originally scheduled.
- Post-termination exercise period for vested options extended through June 30, 2024.
- No successor named; bonus for 2023 at board discretion.

## SEC filing metadata
- accession: 0001619856-23-000138
- form_type: 8-K
- ticker: CRBU
- cik: 0001619856
- company_name: Caribou Biosciences, Inc.
- filed_at: 2023-12-22T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1619856/000161985623000138/0001619856-23-000138-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1619856/000161985623000138/crbu-20231222.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001619856-23-000138
- JSON: https://secwatch.observer/filing/0001619856-23-000138.json
- Plain text: https://secwatch.observer/filing/0001619856-23-000138.txt

## Key facts
- Executive change
  Syed Rizvi departed as Chief Medical Officer at Caribou Biosciences, Inc..
  - Action: leaving
  - Role: Chief Medical Officer
  source text: As previously announced on December 12, 2023, 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/1619856/000161985623000138/0001619856-23-000138-index.htm

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