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 Q1 2020?

82 institutional investors reported MRSN - Mersana Therapeutics, Inc. - Common Stock, par value $0.0001 per share for Q1 2020. Use the holders table for investor-level position and value details.

CUSIP: 59045L106

Q1 2020 13F Holders as of 31 Mar 2020

Security type / class: Equity / Common Stock, par value $0.0001 per share
Total 13F shares: 40,118,913
Total 13F value: $233,891,407
Share change: +4,460,347
SEC-reported price per share: $5.83
Number of holders: 82
Value change: +$26,078,897
Number of buys: 54
Number of sells: 23
Shares outstanding: 4,992,318

Security key

59045L106

Report period

Q1 2020

Institutions

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

NEA Management Company, LLC

Disclosed value leader

NEA Management Company, LLC

Comparable rows

0/15

Latest evidence

31 Dec 2019

13F Highest disclosed value: $68,552,000 15 rows are not safely comparable across share classes. Showing 1-6 of 15 holder rows.

Quick read

NEA Management Company, LLC has the largest disclosed position value at $68.55M.

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 NEA Management Company, LLC's linked filing trail.

Disclosed position value Top 5

NEA Management Company, LLC $68.55M

Sarissa Capital Management LP $21.49M

BlackRock Finance, Inc. $14.13M

ORBIMED ADVISORS LLC $11.88M

VANGUARD GROUP INC $10.7M

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
NEA Management Company, LLC	13F Company 13F	— denominator unverified	$68,552,000 11,963,649 shares	—	31 Dec 2019
Sarissa Capital Management LP	13F Company 13F	— denominator unverified	$21,487,000 3,750,000 shares	—	31 Dec 2019
BlackRock Finance, Inc.	13F Company 13F	— denominator unverified	$14,126,000 2,465,319 shares	—	31 Dec 2019
ORBIMED ADVISORS LLC	13F Company 13F	— denominator unverified	$11,880,000 2,073,319 shares	—	31 Dec 2019
VANGUARD GROUP INC	13F Company 13F	— denominator unverified	$10,699,000 1,867,264 shares	—	31 Dec 2019
VHCP Management III, LLC	13F Company 13F	— denominator unverified	$8,947,000 1,561,389 shares	—	31 Dec 2019

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 Q1 2020

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

Institutions

40,118,913

Rows available

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 Q1 2020 vs Q4 2025 Across Filers

Q4 2025 holders

Q1 2020 holders

Holder diff

Investor	Q4 2025 Shares	Q1 2020 Shares	Share Diff	Share Chg %	Q4 2025 value	Q1 2020 value	Value change	Value Chg %

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

Quarterly Holders Trend

Quarterly Value Trend

Quarterly Shares Trend