Westlake BioPartners
Westlake BioPartners last closed a fund in June 2023 — 41 months ago. By its own rhythm, that is already past its usual gap.
Westlake BioPartners has raised 3 times about every 29 months. The last was Westlake BioPartners Fund III, L.P. That pointed to Nov 2025. It is 12 months past its own gap and has not filed a new fund.
Historically about 1 in 4 firms in this position filed within a year. The month is approximate — how often this is right.
Late-cycle This firm is deep enough into its last fund that a new one would not be a surprise.
- Funds on file
- 4
- Capital raised
- $1.32B
- Latest close
- June 2023
- Based in
- CA
Vehicles on file
| Vehicle | First close | Amount | Filings |
|---|---|---|---|
| Westlake BioPartners Fund III, L.P. | June 2023 | $450M | 0001980313 ↗ |
| Westlake BioPartners Opportunity Fund I, L.P. | July 2020 | $100M | 0001811946 ↗ |
| Westlake BioPartners Fund II, L.P. | July 2020 | $450M | 0001811947 ↗ |
| Westlake BioPartners Fund I, L.P. | August 2018 | $320M | 0001749591 ↗ |
Dated from filing date; no date of first sale was reported.
Each row links to that vehicle’s Form D filings on EDGAR — the name, date and amount above should match what is filed there.
Named on filings
Beth Seidenberg, Scott Ryles, Sean Harper, David Allison, Mira Chaurushiya, Peter Calveley
What Westlake BioPartners invests in
- Typical fund
- $450M median, multistage
- Website
- westlakebio.com
Service providers
- Fund administrator
- Standish (4 funds)
- Auditor
- KPMG (4 funds)
From Form ADV filed by WESTLAKE BIOPARTNERS, LLC CRD 299325 ↗, latest filing March 2026, covering 4 funds linked to this firm by Form D file number. Form ADV is filed once a year, so a provider may have changed since. How this is matched.
What this is. Every figure on this page comes from Form D filings with the U.S. Securities and Exchange Commission — public records, reproduced here as filed. Service providers, where shown, come from the adviser’s Form ADV and are dated.
What it is not. Single-deal SPVs, feeder vehicles and GP or employee commitment funds are listed but excluded from fund counts and capital totals: an SPV is one investment, a feeder holds the same capital as its master, and a “Principals” or “Entrepreneurs” fund closes alongside a main fund rather than being raised in its own right. Capital deployed from a family office, a corporate balance sheet or an evergreen structure never arrives as a fund close, so a firm doing that looks quiet here. Amounts are as of the last amendment and go stale. Dates are the date of first sale — a fund's first close, not its final one. Funds filed as “Indefinite” are excluded from totals rather than counted as zero, so a total is a floor.
“No recent fund” is a statement about filings. It is not a statement about whether a firm is solvent, investing, or still in business.