Quick Takeaways
- Frazier Life Sciences Public Fund, L.P. filed SCHEDULE 13D/A for MBX Biosciences, Inc. Common Stock, $0.0001 par value per share (MBX).
- Disclosed ownership: 14%.
- Date of event: 18 Aug 2025.
Frazier Life Sciences Public Fund, L.P. - 18 Aug 2025 SCHEDULE 13D/A Report for MBX Biosciences, Inc. Common Stock, $0.0001 par value per share (MBX)
- Filing Manager
- Frazier Life Sciences Public Fund, L.P.
- Reporting Manager
- Patrick J. Heron
- Symbol
- MBX
- Shares outstanding
- 33,508,066 shares
- Disclosed Ownership
- 4,557,097 shares
- Ownership
- 14%
- Form type
- SCHEDULE 13D/A
- Filing time
- 20 Aug 2025, 17:23:18 UTC
- Date of event
- 18 Aug 2025
- Next filing
- 30 Sep 2025
- SEC
- View on sec.gov
Quoteable Key Fact
"Frazier Life Sciences Public Fund, L.P. disclosed 14% ownership in MBX Biosciences, Inc. Common Stock, $0.0001 par value per share (MBX) on 18 Aug 2025."
What Changed
- No earlier schedule filing is available for direct comparison.
- Current filing was accepted on 20 Aug 2025, 17:23.
Why This Matters
- This page explains what this Schedule 13D/13G filing tells you before manager-level rows.
- You can verify ownership claims directly against the original SEC filing.
Source Evidence
Backed by Schedule 13D/13G
See Original Filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting Managers (17)
| Name | Ownership | Shares Owned | sole voting power | shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| Frazier Life Sciences Public Fund, L.P. | 3.3% | 1,103,920 | 0 | 1,103,920 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P., GP of Frazier Life Sciences Public Fund, L.P. | 0001863769 |
| FHMLSP, L.P. | 3.3% | 1,103,920 | 0 | 1,103,920 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P. | 0001879466 |
| FHMLSP, L.L.C. | 3.3% | 1,103,920 | 0 | 1,103,920 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLSP, L.L.C. | 0001879465 |
| Frazier Life Sciences Public Overage Fund, L.P. | 1% | 325,653 | 0 | 325,653 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C., GP of FHMLSP Overage, L.P., GP of Frazier Life Sciences Public Overage Fund, L.P. | 0001913804 |
| FHMLSP Overage, L.P. | 1% | 325,653 | 0 | 325,653 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C., GP of FHMLSP Overage, L.P. | 0001963247 |
| FHMLSP Overage, L.L.C. | 1% | 325,653 | 0 | 325,653 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C. | 0001963248 |
| Frazier Life Sciences X, L.P. | 14% | 4,552,774 | 0 | 4,552,774 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P., GP of Frazier Life Sciences X, L.P. | 0001790879 |
| FHMLS X, L.P. | 14% | 4,552,774 | 0 | 4,552,774 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P. | 0001790880 |
| FHMLS X, L.L.C. | 14% | 4,552,774 | 0 | 4,552,774 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLS X, L.L.C. | 0001790811 |
| Frazier Life Sciences XI, L.P. | 0% | 3,000 | 0 | 3,000 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P., GP of Frazier Life Sciences XI, L.P. | 0001911592 |
| FHMLS XI, L.P. | 0% | 3,000 | 0 | 3,000 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P. | 0001911580 |
| FHMLS XI, L.L.C. | 0% | 3,000 | 0 | 3,000 | /s/ Steve R. Bailey | By Steve R. Bailey, CFO of FHMLS XI, L.L.C. | 0001911623 |
| James N. Topper | 14% | 4,552,774 | 0 | 4,552,774 | /s/ Steve R. Bailey | By Steve R. Bailey, Attorney-in-Fact for James N. Topper, pursuant to a Power of Attorney, a copy of which was filed with the SEC on July 31, 2017 | 0001341382 |
| Patrick J. Heron | 14% | 4,557,097 | 4,323 | 4,552,774 | /s/ Steve R. Bailey | By Steve R. Bailey, Attorney-in-Fact for Patrick J. Heron, pursuant to a Power of Attorney, a copy of which was filed with the SEC on July 31, 2017 | 0001365617 |
| Albert Cha | 0% | 0 | 0 | 0 | /s/ Steve R. Bailey | By Steve R. Bailey, Attorney-in-Fact for Albert Cha, pursuant to a Power of Attorney, a copy of which was filed with the SEC on August 16, 2021 | 0001397906 |
| James Brush | 0% | 0 | 0 | 0 | /s/ Steve R. Bailey | By Steve R. Bailey, Attorney-in-Fact for James Brush, pursuant to a Power of Attorney, a copy of which was filed with the SEC on August 16, 2021 | 0001865123 |
| Daniel Estes | 0% | 0 | 0 | 0 | /s/ Steve R. Bailey | By Steve R. Bailey, Attorney-in-Fact for Daniel Estes, pursuant to a Power of Attorney, a copy of which was filed with the SEC on April 18, 2022 | 0001702527 |