---
schema_version: "secwatch.filing_event.v1"
accession: "0001619856-24-000074"
form_type: "8-K/A"
ticker: "CRBU"
cik: "0001619856"
company_name: "Caribou Biosciences, Inc."
filed_at: "2024-09-27T23:59:59+00:00"
generated_at: "2026-05-31T01:10:33.776229+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Caribou Biosciences appoints Ryan Fischesser interim CFO and grants 25,000 RSUs

## Summary
- Ryan Fischesser designated interim principal financial officer and accounting officer effective Sept 27, 2024, following Jason O'Byrne's resignation.
- Fischesser to receive 25,000 RSUs on Nov 20, 2024, vesting fully on Nov 20, 2025, subject to continued employment.
- The original 8-K filed Sept 3, 2024 reported O'Byrne's resignation; this amendment supplements compensatory terms.
- Fischesser previously served as VP of Finance and Controller.

## SEC filing metadata
- accession: 0001619856-24-000074
- form_type: 8-K/A
- ticker: CRBU
- cik: 0001619856
- company_name: Caribou Biosciences, Inc.
- filed_at: 2024-09-27T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1619856/000161985624000074/0001619856-24-000074-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1619856/000161985624000074/crbu-20240901.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001619856-24-000074
- JSON: https://secwatch.observer/filing/0001619856-24-000074.json
- Plain text: https://secwatch.observer/filing/0001619856-24-000074.txt

## Key facts
- Executive change
  Ryan Fischesser was appointed as Interim Principal Financial Officer and Interim Principal Accounting Officer at Caribou Biosciences, Inc..
  - Action: designated
  - Role: Interim Principal Financial Officer and Interim Principal Accounting Officer
  source text: On September 23, 2024, Caribou Biosciences, Inc. (the “Company”) designated Ryan Fischesser, the Company’s current Vice President of Finance and Controller, as the Company’s interim principal financial officer and interim principal accounting officer, effective as of 5:00 p.m. Pacific time on September 27, 2024.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1619856/000161985624000074/0001619856-24-000074-index.htm
- Executive change
  Jason O'Byrne resigned as Chief Financial Officer at Caribou Biosciences, Inc..
  - Action: resigned
  - Role: Chief Financial Officer
  source text: Mr. O’Byrne serves as the Company’s principal financial officer and principal accounting officer through September 27, 2024, his final day with the Company.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1619856/000161985624000074/0001619856-24-000074-index.htm

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