🕵️ Mersana Therapeutics, Inc. ($MRSN)
SEC insider & ownership activity, last 12 months · CIK 1442836 · every row links its SEC filing
Over the last 12 months insiders sold $15K with no open-market buying against it. Martin H. Huber Jr. sold $15K through a 10b5-1 trading plan in 1 lots (Sep). 2 red-flag 8-Ks in the window, most recently Delisting notice (3.01), Jan 5, 2026.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
0 buyers, $0 (0 lots) · 2 sellers, $15K (2 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Martin H. Huber Jr. | 0 | – | 1 | $15K | Sep 12, 2025 |
| Mohan Bala | 0 | – | 1 | $762 | Oct 27, 2025 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Nextech Crossover I GP S.A. R.L. | 10.4% | 13G | Dec 26, 2024 | filing ↗ | |
| Nextech Crossover I Scsp | 10.4% | 13G | Dec 26, 2024 | filing ↗ | |
| Ian Charoub | 10.4% | 13G | Dec 26, 2024 | filing ↗ | |
| Costas Constantinides | 10.4% | 13G | Dec 26, 2024 | filing ↗ | |
| Rocco Sgobbo | 10.4% | 13G | Dec 26, 2024 | filing ↗ | |
| ECOR1 Capital, LLC | 10.0% | 13G | Dec 23, 2024 | filing ↗ | |
| Oleg Nodelman | 10.0% | 13G | Dec 23, 2024 | filing ↗ | |
| ECOR1 Capital Fund Qualified, L.P. | 9.4% | 13G | Dec 23, 2024 | filing ↗ |
Planned insider sales (Form 144)
No sale notices filed in the last 12 months.
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Agreement terminated (1.02) | Jan 5, 2026 | filing ↗ |
| Acquisition or disposition (2.01) | Jan 5, 2026 | filing ↗ |
| Delisting notice (3.01) | Jan 5, 2026 | filing ↗ |
| Material Modifications to Rights of Security Holders (3.03) | Jan 5, 2026 | filing ↗ |
| Change of control (5.01) | Jan 5, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jan 5, 2026 | filing ↗ |
| Charter/bylaw changes (5.03) | Jan 5, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 5, 2026 | filing ↗ |
| Earnings (2.02) | Nov 14, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 14, 2025 | filing ↗ |
| Material agreement (1.01) | Nov 12, 2025 | filing ↗ |
| Other events (8.01) | Nov 12, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 12, 2025 | filing ↗ |
| Delisting notice (3.01) | Sep 5, 2025 | filing ↗ |
| Earnings (2.02) | Aug 13, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 13, 2025 | filing ↗ |