Acquired Company

Day One Biopharmaceuticals completed its acquisition of Mersana Therapeutics, Inc. on January 6, 2026, at $25 per share in cash plus one non-tradable contingent value right per share.

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. Show more

Location: 840 Memorial Drive, Cambridge, MA, 02139, United States | Website: https://www.mersana.com | Industry: Biotechnology | Sector: Healthcare

Market Cap

145.4M

52 Wk Range

$5.21 - $30.39

Previous Close

$29.08

Open

$29.08

Volume

N/A

Day Range

$29.08 - $29.08

Enterprise Value

91.27M

Cash

56.39M

Avg Qtr Burn

-18.59M

Insider Ownership

1.47%

Institutional Own.

67.57%

Qtr Updated

09/30/25

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Drug & Indication	Stage & Event	Catalyst Date
Emiltatug Ledadotin (Emi-Le; XMT-1660) Details Ovarian cancer, Breast cancer, Endometrial cancer	Phase 1 Update	Some catalyst date You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details.Sign up now.
XMT-2056 (HER2 ADC) Details Solid tumor/s, Non-small cell lung carcinoma, Cancer	Phase 1 Update	Some catalyst date You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details.Sign up now.
Upifitamab Risodotin (UpRi) (XMT-1536) (NAPi2b ADC) Details Ovarian cancer, Solid tumor/s, Cancer	Failed Discontinued	Some catalyst date You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details.Sign up now.
Upifitamab Risodotin (UpRi) (XMT-1536) (NAPi2b ADC) Details Ovarian cancer, Solid tumor/s, Cancer	Failed Discontinued	Some catalyst date You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details.Sign up now.
Upifitamab Risodotin (UpRi) (XMT-1536) (NAPi2b ADC) Details Ovarian cancer, Solid tumor/s, Cancer	Failed Discontinued	Some catalyst date You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details.Sign up now.
XMT-1592 (NaPi2b antigen) Details Solid tumor/s, Non-small cell lung carcinoma, Cancer	Failed Discontinued	Some catalyst date You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details. You must sign up to see the catalyst details.Sign up now.