MBX Biosciences's top three insider shareholders as of April 28, 2026 are Patrick J Heron (Director, 5.22Mn shares), Life Sciences X, L.P. Frazier (TenPercentOwner, 4.55Mn shares), Life Sciences X, L.P. Frazier (TenPercentOwner, 4.55Mn shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Patrick J Heron | - | 0 | 5,219,440 | 30 Sep, 2025 |
| Life Sciences X, L.P. Frazier | - | 4,552,774 | 0 | 17 Sep, 2024 |
| Life Sciences X, L.P. Frazier | - | 4,552,774 | 0 | 17 Sep, 2024 |
| Advisors Llc Orbimed | - | 0 | 3,812,215 | 17 Sep, 2024 |
| Carl L Gordon | - | 0 | 3,812,215 | 17 Sep, 2024 |
| Rick Yang | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Rick Yang | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Paul Edward Walker | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Enterprise Associates 17, L.P. New | - | 3,614,486 | 0 | 17 Sep, 2024 |
| Anthony A. Jr. Florence | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Mohamad Makhzoumi | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Edward T Mathers | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Carmen Chang | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Ali Behbahani | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Forest Baskett | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Paul Edward Walker | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Enterprise Associates 17, L.P. New | - | 3,614,486 | 0 | 17 Sep, 2024 |
| Scott D Sandell | - | 0 | 3,614,486 | 17 Sep, 2024 |
| Tiba Aynechi | - | 0 | 2,136,335 | 17 Sep, 2024 |
| Biomedical Innovation Master Investors (Cayman) Ii L.P. Wellington | - | 1,790,122 | 0 | 17 Sep, 2024 |
| Biomedical Innovation Master Investors (Cayman) Ii L.P. Wellington | - | 1,790,122 | 0 | 17 Sep, 2024 |
| Carl L Gordon | - | 0 | 747,887 | 19 Feb, 2025 |
| Advisors Llc Orbimed | - | 0 | 747,887 | 19 Feb, 2025 |
| P. Kent Hawryluk | President Ceo | 728,274 | 0 | 27 Feb, 2026 |
| P. Kent Hawryluk | President Ceo | 0 | 486,777 | 16 Mar, 2026 |
| James M Cornelius | - | 102,082 | 0 | 17 Sep, 2024 |
| Ora H. Pescovitz | - | 24,329 | 0 | 10 Apr, 2025 |
| Ora H. Pescovitz | - | 24,329 | 0 | 10 Apr, 2025 |
| Steven L. Hoerter | - | 0 | 20,000 | 20 Oct, 2025 |
| Salomon Azoulay | Chief Medical Officer | 15,000 | 0 | 03 Feb, 2026 |
| Richard Bartram | Chief Financial Officer | 15,000 | 0 | 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 |
|---|---|---|---|---|---|---|---|---|
| 13 Mar, 2026 | P. Kent Hawryluk | Common Stock | A | 18,500 | $28.41 | 486,777 | I | P |
| 26 Feb, 2026 | P. Kent Hawryluk | Common Stock | A | 28,768 | $16.00 | 728,274 | D | M |
| 26 Feb, 2026 | P. Kent Hawryluk | Stock option (right to buy) | D | 28,768 | $0.00 | 91,668 | D | M |
| 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 |
| 02 Feb, 2026 | Salomon Azoulay | Stock option (right to buy) | A | 70,000 | $0.00 | 70,000 | D | A |
| 02 Feb, 2026 | Richard Bartram | Stock option (right to buy) | A | 70,000 | $0.00 | 70,000 | D | A |
| 02 Feb, 2026 | P. Kent Hawryluk | Stock option (right to buy) | A | 164,500 | $0.00 | 164,500 | D | A |
| 20 Jan, 2026 | Laurie Stelzer | Stock option (right to buy) | A | 32,000 | $0.00 | 32,000 | D | A |
| 22 Nov, 2025 | Steven L. Hoerter | Stock option (right to buy) | A | 8,000 | $0.00 | 8,000 | D | A |
| 06 Nov, 2025 | Steven L. Hoerter | Stock option (right to buy) | A | 100,000 | $0.00 | 100,000 | D | A |
| 24 Oct, 2025 | P. Kent Hawryluk | Common Stock | A | 182,859 | $3.25 | 664,256 | D | M |
| 24 Oct, 2025 | P. Kent Hawryluk | Stock option (right to buy) | D | 182,859 | $0.00 | 129,708 | D | M |
| 20 Oct, 2025 | P. Kent Hawryluk | Common Stock | A | 20,000 | $13.64 | 468,277 | I | P |
| 17 Oct, 2025 | Steven L. Hoerter | Common Stock | A | 20,000 | $13.25 | 20,000 | I | P |
| 05 Jun, 2025 | James M Cornelius | Stock option (right to buy) | A | 16,000 | $0.00 | 16,000 | D | A |
| 05 Jun, 2025 | Tiba Aynechi | Stock option (right to buy) | A | 16,000 | $0.00 | 16,000 | D | A |
| 05 Jun, 2025 | Steven Ryder | Stock option (right to buy) | A | 16,000 | $0.00 | 16,000 | D | A |
| 05 Jun, 2025 | Ora H. Pescovitz | Stock option (right to buy) | A | 16,000 | $0.00 | 16,000 | D | A |