Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (MRSN)

Q: What does CUSIP 59045L106 represent in this 13F holders report?

CUSIP 59045L106 is the security identifier for MRSN - Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share used to aggregate holder disclosures.

Q: How many institutions held MRSN - Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share in Q3 2022?

147 institutional investors reported MRSN - Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share for Q3 2022. Use the holders table for investor-level position and value details.

CUSIP: 59045L106

Q3 2022 13F Holders as of 30 Sep 2022

Security type / class: Equity / Common Stock, par value $0.0001 per share
Total 13F shares: 92,449,667
Total 13F value: $624,973,128
Share change: +4,416,480
SEC-reported price per share: $6.76
Number of holders: 147
Value change: +$39,050,654
Number of buys: 100
Number of sells: 38
Shares outstanding: 4,992,318

Security key

59045L106

Report period

Q3 2022

Institutions

147

Top holders

MRSN full security history Ownership snapshot Full 13F holder table Newer quarter: Q4 2025 Mersana Therapeutics, Inc. SEC filings Mersana Therapeutics, Inc. company facts

Broader feeds

Latest 13F filings Latest 13D/G filings Investors directory

Reporting periods

Holder history for CUSIP 59045L106

Newer quarter: Q4 2025

Recent filing periods:

Q1 2026 Q4 2025

Ownership snapshot

Top reported holders of MRSN - Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader

ORBIMED ADVISORS LLC

Disclosed value leader

ORBIMED ADVISORS LLC

Comparable rows

0/15

Latest evidence

30 Jun 2022

13F Highest disclosed value: $41,633,000 15 rows are not safely comparable across share classes. Showing 1-6 of 15 holder rows.

Quick read

ORBIMED ADVISORS LLC has the largest disclosed position value at $41.63M.

0 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens ORBIMED ADVISORS LLC's linked filing trail.

Disclosed position value Top 5

ORBIMED ADVISORS LLC $41.63M

BlackRock Finance, Inc. $41.03M

Bain Capital Life Sciences Invest... $40.03M

Avoro Capital Advisors LLC $34.88M

VANGUARD GROUP INC $21.87M

Value bars compare disclosed positions; verify each figure against the linked filing evidence.

Detailed SEC evidence table Showing 1-6 of 15 holder rows

Holder	Evidence	Ownership %	Position	12M Net Δ	As of
ORBIMED ADVISORS LLC	13F Company 13F	— denominator unverified	$41,633,000 9,011,437 shares	—	30 Jun 2022
BlackRock Finance, Inc.	13F Company 13F	— denominator unverified	$41,030,000 8,881,019 shares	—	30 Jun 2022
Bain Capital Life Sciences Investors, LLC	13F Company 13F	— denominator unverified	$40,026,000 8,663,673 shares	—	30 Jun 2022
Avoro Capital Advisors LLC	13F Company 13F	— denominator unverified	$34,881,000 7,550,000 shares	—	30 Jun 2022
VANGUARD GROUP INC	13F Company 13F	— denominator unverified	$21,871,000 4,733,731 shares	—	30 Jun 2022
MILLENNIUM MANAGEMENT LLC	13F Company 13F	— denominator unverified	$20,248,000 4,382,701 shares	—	30 Jun 2022

How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

13F holder rows

Institutional holders as of Q3 2022

Investor-level positions for this CUSIP, loaded as an interactive table.

Institutions

147

92,449,667

Rows available

147

Investor	Option	Weight %	Change %	SEC-reported value	* Price	Shares	Share Change	Activity	Report Period

^* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.

Compare Q3 2022 vs Q4 2025 Across Filers

Q4 2025 holders

Q3 2022 holders

147

Holder diff

144

Investor	Q4 2025 Shares	Q3 2022 Shares	Share Diff	Share Chg %	Q4 2025 value	Q3 2022 value	Value change	Value Chg %

Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).

Quarterly Holders Trend

Quarterly Value Trend

Quarterly Shares Trend