How many insider trades does FilingIQ track for MRSN?

FilingIQ tracks 681 Form 4 insider transactions for MRSN (Mersana Therapeutics, Inc.), covering filings from Jul 3, 2017 onwards. 0 of those were filed in the last 90 days.

Are MRSN insiders net buyers or net sellers?

Across the full Form 4 history for MRSN, 35 transactions (5%) were open-market purchases and 113 (17%) were open-market sales. Compensatory awards and option exercises are filtered out of these counts.

Where does MRSN insider data come from?

Every transaction shown on this page is sourced directly from SEC EDGAR Form 4 filings. FilingIQ parses the raw XML, normalises insider identity across reporting variations, and scores each trade on its multi-factor composite model.

What sector is MRSN in?

Mersana Therapeutics, Inc. (MRSN) is classified in the Healthcare sector, specifically Biotechnology, with a current market capitalisation of $145.36M.

MRSN insider trading

NasdaqGS Healthcare

Mersana Therapeutics, Inc. — scored insider trade history from SEC Form 4 filings, parsed and contextualised by FilingIQ.

Total Form 4 trades

681

Last 90 days

Buys / sells

5% / 17%

Market cap

$145.36M

About Mersana Therapeutics, Inc.

Mersana Therapeutics, Inc., a clinical-stage biopharmaceutical company, develops antibody-drug conjugates (ADC) for cancer patients with unmet needs. The company develops Emi-Le (XMT-1660), a B7-H4-targeting Dolasynthen ADC candidate, which is in Phase 1 clinical trial; and XMT-2056, an Immunosynthen ADC targeting a novel human epidermal growth factor receptor 2 that is in Phase 1 clinical trial. Its preclinical products portfolio includes XMT-2068 and XMT-2175. It has strategic research and development collaborations with Janssen Biotech, Inc., Ares Trading S.A., Merck KGaA, and Asana Biosciences, LLC for the development of ADC product candidates. The company was formerly known as Nanopharma Corp. and changed its name to Mersana Therapeutics, Inc. in November 2005. Mersana Therapeutics, Inc. was incorporated in 2001 and is headquartered in Cambridge, Massachusetts. As of January 6, 2026, Mersana Therapeutics, Inc. operates as a subsidiary of Day One Biopharmaceuticals, Inc.

Company website: www.mersana.com

MRSN insider activity at a glance

FilingIQ has scored 681 insider transactions for MRSN since Jul 3, 2017. The most recent filing in our index is dated Jan 6, 2026.

Across the full history, 35 open-market purchases and 113 open-market sales were filed under transaction codes P and S respectively. Compensatory share awards (code A) and option exercises (code M) are tracked separately and not counted here.

The average FilingIQ composite score on MRSN insider trades is 57.2/100, produced by FilingIQ's multi-factor Form 4 model. Model framework documented at methodology.

View live MRSN trades on FilingIQ Raw filings on SEC EDGAR

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13F funds holding MRSN

Decheng Capital Management III (Cayman), LLC

$1.15M · 0.4% of AUM

Frequently asked

How many insider trades does FilingIQ track for MRSN?: FilingIQ tracks 681 Form 4 insider transactions for MRSN (Mersana Therapeutics, Inc.), covering filings from Jul 3, 2017 onwards. 0 of those were filed in the last 90 days.
Are MRSN insiders net buyers or net sellers?: Across the full Form 4 history for MRSN, 35 transactions (5%) were open-market purchases and 113 (17%) were open-market sales. Compensatory awards and option exercises are filtered out of these counts.
Where does MRSN insider data come from?: Every transaction shown on this page is sourced directly from SEC EDGAR Form 4 filings. FilingIQ parses the raw XML, normalises insider identity across reporting variations, and scores each trade on its multi-factor composite model.
What sector is MRSN in?: Mersana Therapeutics, Inc. (MRSN) is classified in the Healthcare sector, specifically Biotechnology, with a current market capitalisation of $145.36M.

Methodology & sources

Every MRSN insider transaction shown on FilingIQ is parsed directly from a public SEC Form 4 XML filing. Insider identity is normalised across reporting variants (CIK changes, name spellings, related-party indirect holdings). The FilingIQ composite score is documented in full on the team page and algo disclosure. Not investment advice; see disclaimer.