Over the 90-day window ending February 19, 2026, MBX Biosciences's three dominant insider ownership positions are held by Director Patrick J Heron (5.22Mn shares), TenPercentOwner Life Sciences X, L.P. Frazier (4.55Mn shares), TenPercentOwner Forest Baskett (3.61Mn shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Patrick J Heron | 5,219,440 | 30 Sep, 2025 | |
| Life Sciences X, L.P. Frazier | 4,552,774 | 17 Sep, 2024 | |
| Scott D Sandell | 3,614,486 | 17 Sep, 2024 | |
| Forest Baskett | 3,614,486 | 17 Sep, 2024 | |
| Edward T Mathers | 3,614,486 | 17 Sep, 2024 | |
| Rick Yang | 3,614,486 | 17 Sep, 2024 | |
| Enterprise Associates 17, L.P. New | 3,614,486 | 17 Sep, 2024 | |
| Carmen Chang | 3,614,486 | 17 Sep, 2024 | |
| Anthony A. Jr. Florence | 3,614,486 | 17 Sep, 2024 | |
| Ali Behbahani | 3,614,486 | 17 Sep, 2024 | |
| Mohamad Makhzoumi | 3,614,486 | 17 Sep, 2024 | |
| Paul Edward Walker | 3,614,486 | 17 Sep, 2024 | |
| Tiba Aynechi | 2,136,335 | 17 Sep, 2024 | |
| Biomedical Innovation Master Investors (Cayman) Ii L.P. Wellington | 1,790,122 | 17 Sep, 2024 | |
| P. Kent Hawryluk | President & Ceo | 1,147,783 | 03 Feb, 2026 |
| Advisors Llc Orbimed | 747,887 | 19 Feb, 2025 | |
| Carl L Gordon | 747,887 | 19 Feb, 2025 | |
| James M Cornelius | 102,082 | 17 Sep, 2024 | |
| Ora H. Pescovitz | 24,329 | 10 Apr, 2025 | |
| Steven L. Hoerter | 20,000 | 20 Oct, 2025 | |
| Richard Bartram | Chief Financial Officer | 15,000 | 03 Feb, 2026 |
| Salomon Azoulay | Chief Medical Officer | 15,000 | 03 Feb, 2026 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 02 Feb, 2026 | P. Kent Hawryluk | Common Stock | A | 35,250 | $0.00 | 699,506 | D | A |
| 02 Feb, 2026 | Richard Bartram | Common Stock | A | 15,000 | $0.00 | 15,000 | D | A |
| 02 Feb, 2026 | Salomon Azoulay | Common Stock | A | 15,000 | $0.00 | 15,000 | D | A |
| 24 Oct, 2025 | P. Kent Hawryluk | Common Stock | A | 182,859 | $3.25 | 664,256 | D | M |
| 20 Oct, 2025 | P. Kent Hawryluk | Common Stock | A | 20,000 | $13.64 | 481,397 | D | P |
| 17 Oct, 2025 | Steven L. Hoerter | - | - | 20,000 | I | |||
| 17 Oct, 2025 | Steven L. Hoerter | Common Stock | A | 20,000 | $13.25 | 20,000 | I | P |
| 26 Sep, 2025 | Patrick J Heron | Common Stock | A | 666,666 | $18.00 | 5,219,440 | I | P |
| 26 Sep, 2025 | Patrick J Heron | - | - | 5,219,440 | I | |||
| 08 Apr, 2025 | Ora H. Pescovitz | - | - | 24,329 | D | |||
| 08 Apr, 2025 | Ora H. Pescovitz | Common Stock | A | 7,693 | $5.89 | 24,329 | D | P |
| 18 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 94,100 | $10.84 | 747,887 | I | P |
| 18 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 49,070 | $10.84 | 3,255,000 | I | P |
| 18 Feb, 2025 | Carl L Gordon | Common Stock | A | 49,070 | $10.84 | 3,255,000 | I | P |
| 18 Feb, 2025 | Carl L Gordon | - | - | 747,887 | I | |||
| 18 Feb, 2025 | Carl L Gordon | Common Stock | A | 94,100 | $10.84 | 747,887 | I | P |
| 18 Feb, 2025 | Carl L Gordon | - | - | 3,255,000 | I | |||
| 14 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 29,540 | $9.85 | 3,205,930 | I | P |
| 14 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 17,962 | $9.90 | 3,176,390 | I | P |
| 14 Feb, 2025 | Advisors Llc Orbimed | - | - | 3,176,390 | I |