---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-23-040172"
form_type: "8-K"
ticker: null
cik: "0001442836"
company_name: "Mersana Therapeutics, Inc."
filed_at: "2023-03-31T23:59:59+00:00"
generated_at: "2026-06-17T07:45:12.727692+00:00"
event_type: "other"
sentiment: "neutral"
materiality_score: 0.05
calibrated_materiality_score: 0.05
confidence: "high"
source: SEC EDGAR
---

# Mersana Therapeutics adopts amended bylaws with universal proxy rule updates

## Summary
- Board adopted Second Amended and Restated Bylaws on March 31, 2023, effective immediately.
- Enhanced disclosure and procedural requirements for stockholder director nominations, aligning with SEC universal proxy rules.
- Requires proof of compliance with Rule 14a-19; non-compliance allows disregarding nominations and votes.
- Limits stockholder nominees to number of directors to be elected; removes stockholder list display during remote meetings.
- Added emergency bylaw provision and other conforming changes to Delaware General Corporation Law.

## SEC filing metadata
- accession: 0001104659-23-040172
- form_type: 8-K
- cik: 0001442836
- company_name: Mersana Therapeutics, Inc.
- filed_at: 2023-03-31T23:59:59+00:00
- event_type: other
- sentiment: neutral
- materiality_score: 0.05
- calibrated_materiality_score: 0.05
- confidence: high
- sec_items: 5.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1442836/000110465923040172/0001104659-23-040172-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1442836/000110465923040172/tm2311091d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-23-040172
- JSON: https://secwatch.observer/filing/0001104659-23-040172.json
- Plain text: https://secwatch.observer/filing/0001104659-23-040172.txt

## Key facts
- Governance Changes
  Mersana Therapeutics, Inc.: Amended and restated bylaws to adopt universal proxy rules, revise stockholder meeting procedures, add emergency bylaw provision, and make other updates (effective 2023-03-31).
  - Change: bylaw amendment
  - Effective: 2023-03-31
  source text: On March 31, 2023 , the Board of Directors (the “Board”) of Mersana Therapeutics, Inc. (the “Company”) adopted and approved the Company’s Second Amended and Restated Bylaws (as so amended and restated, the "Bylaws").
  evidence_url: https://www.sec.gov/Archives/edgar/data/1442836/000110465923040172/0001104659-23-040172-index.htm

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