Bain Capital Life Sciences Fund II, L.P.

13F Holdings History for Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (MRSN)

Symbol: MRSN on Nasdaq
Investment type: Equity / Common Stock, par value $0.0001 per share
Latest Disclosed Ownership: 199K shares
Security Ownership: 4%

BCLS II Investco, LP ownership in Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share (MRSN)

2025-11-13 - BCLS II Investco, LP has filed an SCHEDULE 13D/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 199K shares of Mersana Therapeutics, Inc. Common Stock, par value $0.0001 per share (MRSN). This represents 4% percent ownership of the company.

Reporting Name	Ownership %	Change	Value $	Shares owned	Change	Activity %	Price	Form	Report date	Filed at
BCLS II Investco, LP	4%		$1.52M	199K			$7.64	13D/A	11/12/2025	13 Nov 2025 18:45:02