---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-23-098499"
form_type: "8-K"
ticker: null
cik: "0001442836"
company_name: "Mersana Therapeutics, Inc."
filed_at: "2023-09-06T23:59:59+00:00"
generated_at: "2026-06-10T23:20:10.496112+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# CEO Protopapas retires; Dr. Martin Huber takes over; CMO Dr. Arvin Yang departs

## Summary
- CEO Anna Protopapas retires effective Sept 10; remains on board; receives prorated 2023 bonus and extended equity vesting.
- Dr. Martin Huber appointed President & CEO effective Sept 11; base salary $625K, target bonus 60%, option for 1M shares, RSU for 667K shares.
- CMO Dr. Arvin Yang last day Sept 29; severance of 9 months base salary plus COBRA premiums.
- Brian DeSchuytner named SVP, COO & CFO; Mohan Bala named SVP, Chief Development Officer; Ashish Mandelia VP, Chief Accounting Officer.
- Compensation Committee granted 330,000 RSUs as retention awards to senior management, vesting Oct 1, 2024.

## SEC filing metadata
- accession: 0001104659-23-098499
- form_type: 8-K
- cik: 0001442836
- company_name: Mersana Therapeutics, Inc.
- filed_at: 2023-09-06T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 5.02, 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1442836/000110465923098499/0001104659-23-098499-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1442836/000110465923098499/tm2325490d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-23-098499
- JSON: https://secwatch.observer/filing/0001104659-23-098499.json
- Plain text: https://secwatch.observer/filing/0001104659-23-098499.txt

## Key facts
- Executive change
  Martin Huber was appointed as President and Chief Executive Officer at Mersana Therapeutics, Inc..
  - Action: appointed
  - Role: President and Chief Executive Officer
  source text: Martin Huber, M.D., was appointed as the Company’s President and Chief Executive Officer, effective as of September 11, 2023
  evidence_url: https://www.sec.gov/Archives/edgar/data/1442836/000110465923098499/0001104659-23-098499-index.htm
- Executive change
  Anna Protopapas retired as President and Chief Executive Officer at Mersana Therapeutics, Inc..
  - Action: retired
  - Role: President and Chief Executive Officer
  source text: Anna Protopapas, President and Chief Executive Officer of Mersana Therapeutics, Inc. (the “Company”), provided the Company with notice of her desire and intention to retire, and on September 6, 2023, the Company announced Ms. Protopapas’ retirement effective as of September 10, 2023
  evidence_url: https://www.sec.gov/Archives/edgar/data/1442836/000110465923098499/0001104659-23-098499-index.htm

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