---
schema_version: "secwatch.filing_event.v1"
accession: "0001140361-23-021828"
form_type: "8-K"
ticker: "TECX"
cik: "0001681087"
company_name: "Tectonic Therapeutic, Inc."
filed_at: "2023-05-01T23:59:59+00:00"
generated_at: "2026-06-16T05:08:05.136015+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# AVROBIO CEO Geoff MacKay resigns; CFO Erik Ostrowski named interim CEO

## Summary
- CEO Geoff MacKay resigns effective May 1, 2023, to join an early-stage company; no disagreement with the company.
- CFO Erik Ostrowski appointed President and Interim CEO, effective May 1, 2023; will continue as CFO.
- Board of Directors begins search for a permanent CEO; Ostrowski has over 20 years of biotech finance experience.
- MacKay served as founding CEO for eight years; company transitioning to late-stage development for Gaucher and cystinosis programs.

## SEC filing metadata
- accession: 0001140361-23-021828
- form_type: 8-K
- ticker: TECX
- cik: 0001681087
- company_name: Tectonic Therapeutic, Inc.
- filed_at: 2023-05-01T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1681087/000114036123021828/0001140361-23-021828-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1681087/000114036123021828/ny20008949x1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001140361-23-021828
- JSON: https://secwatch.observer/filing/0001140361-23-021828.json
- Plain text: https://secwatch.observer/filing/0001140361-23-021828.txt

## Key facts
- Executive change
  Erik Ostrowski was appointed as President and Interim Chief Executive Officer at Tectonic Therapeutic, Inc..
  - Action: appointed
  - Role: President and Interim Chief Executive Officer
  source text: On April 28, 2023, the Board appointed Erik Ostrowski, the Company’s current Chief Financial Officer and Treasurer, as the Company’s President and Interim Chief Executive Officer, effective at 1:00 p.m. ET on May 1, 2023.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1681087/000114036123021828/0001140361-23-021828-index.htm
- Executive change
  Geoff MacKay resigned as President and Chief Executive Officer at Tectonic Therapeutic, Inc..
  - Action: resigned
  - Role: President and Chief Executive Officer
  source text: On April 28, 2023, Geoff MacKay provided notice of his resignation as President and Chief Executive Officer and a member of the Board of Directors (the “ Board ”) of AVROBIO, Inc. (the “ Company ”), effective at 1:00 p.m. ET on May 1, 2023.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1681087/000114036123021828/0001140361-23-021828-index.htm

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