M&A · Healthcare · Pharmaceutical Preparations
Day One Biopharmaceuticals, Inc. to acquire Mersana Therapeutics, Inc.
Announced Nov 13, 2025 · Closed Jan 6, 2026
Deal value$129MEV $69M
Premium—To unaffected price
EV / Adj. EBITDA—2.0x EV / Revenue
ConsiderationAll cash$25.00 per share
Transaction
- Acquirer
- Day One Biopharmaceuticals, Inc.
- Target
- Mersana Therapeutics, Inc. (MRSN)
- Buyer type
- Strategic
- Offer price per share
- $25.00
- Enterprise value
- $69M
- Status
- Closed Jan 6, 2026
Deal protections
- Break fee (target pays)
- $5.6M · 4.3%
- Reverse fee (buyer pays)
- —
- Go-shop
- No-shop
- Financing
- No financing condition
Advisors
- To the acquirer
- Not disclosed
- To the target
- TD Cowen
- TD Cowen fee
- $3.5M
Sector context · Healthcare
- Comparable deals
- 97 in the prior 24 months
- Premium
- Sector median 59.5%
- EV / Adj. EBITDA
- Sector median 14.5x
- Break fee
- 4.3% vs. 3.4% sector median
Timeline
- AnnouncedNov 13, 2025
- Tender offerDec 5, 2025
- ClosedJan 6, 2026
Valuation · fairness opinions
Precedent transactions$12.00$46.00
Discounted cash flow$8.00$11.00
Discounted cash flow$8.00$68.00
Discounted cash flow$9.00$68.00
Offer $25.00
Implied value per Mersana Therapeutics, Inc. share by analysis, from TD Cowen.