683 Capital Management, LLC - 17 Nov 2025 SCHEDULE 13G Report for Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share (MRSN)

Filing Manager
683 Capital Management, LLC
Reporting Manager
683 Capital Management, LLC
Security
Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share
Symbol
MRSN
Shares outstanding
4,998,537 shares
Disclosed Ownership
273,420 shares
Ownership
5.5%
Form type
SCHEDULE 13G
Filing time
24 Nov 2025, 17:12:46 UTC
Date of event
17 Nov 2025
Next filing
17 Feb 2026
SEC
View on sec.gov

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Quoteable Key Fact

"683 Capital Management, LLC disclosed 5.5% ownership in Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share (MRSN) on 17 Nov 2025."

Quick Takeaways

  • 683 Capital Management, LLC filed SCHEDULE 13G for Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share (MRSN).
  • Disclosed ownership: 5.5%.
  • Date of event: 17 Nov 2025.

What Changed

  • No earlier schedule filing is available for direct comparison.
  • Current filing was accepted on 24 Nov 2025, 17:12.

Why This Matters

  • This page explains what this Schedule 13D/13G filing tells you before manager-level rows.
  • You can verify ownership claims directly against the original SEC filing.

Official SEC Source

Backed by Schedule 13D/13G

Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.

See Original Filing

Reporting Managers (3)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
683 Capital Management, LLC 5.5% 273,420 0 273,420 Ari Zweiman Managing Member
683 Capital Partners, LP 5.5% 273,420 0 273,420 Ari Zweiman Authorized Person
Ari Zweiman 5.5% 273,420 0 273,420 Ari Zweiman Self

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