Westlake Biopartners, LLC
SEC exempt reporting adviser (venture capital exemption).
- HQ
- CA
Westlake BioPartners is a life science venture capital firm that says people are central to its approach. It supports entrepreneurs from early ideation and preclinical research through clinical and commercial impact. The firm lists team members including a Finance Manager, a Director of Administration, and a VP of Finance and Operations. It also notes a portfolio company, Acelyrin, which merged with Alumis in 2025.
01 · Says / Does
| Tag | Says | Does |
|---|---|---|
| Stages | Not stated | Not enough dated deals |
| Sectors | Biotech | Not enough dated deals |
| Regions | CA | Not enough dated deals |
Says: what the firm's funds state. Does: from 0 dated deals in the last 24 months.
02 · Fund history
| Fund | Year | Size | Status |
|---|---|---|---|
| Westlake BioPartners Fund III, L.P. Westlake BioPartners is a people-first life science venture capital firm that backs entrepreneurs from ideation and preclinical research through clinical and commercial impact, aiming to bring life-changing medicines to patients with unmet needs. Inferred from the firm's website | approx. 2023 | $450M to $456.01M (Form D and SEC adviser filing) | Open, writing first checks |
| Westlake BioPartners Fund II, L.P. | approx. 2020 | $450M (Form D) | Follow-ons only |
03 · People across funds
- Beth Seidenberg, Managing Director of the General Partner
Westlake BioPartners Fund III, L.P. (Named on Form D); Westlake BioPartners Fund II, L.P. (Named on Form D)
- David Allison, Managing Director of the General Partner
Westlake BioPartners Fund III, L.P. (Named on Form D)
- Mira Chaurushiya, Managing Director of the General Partner
Westlake BioPartners Fund III, L.P. (Named on Form D)
- Scott Ryles, Chief Operating Officer of the General Partner
Westlake BioPartners Fund II, L.P. (Named on Form D)
- Sean Harper, Managing Director of the General Partner
Westlake BioPartners Fund II, L.P. (Named on Form D)
- Armando Alvarez, CPA, Finance Manager
Westlake BioPartners Fund III, L.P. (Team); Westlake BioPartners Fund II, L.P. (Team)
- Brogan Perrelli, CPA, VP Finance & Operations
Westlake BioPartners Fund III, L.P. (Team); Westlake BioPartners Fund II, L.P. (Team)
- Kelli McKeirnan, Director of Administration
Westlake BioPartners Fund III, L.P. (Team); Westlake BioPartners Fund II, L.P. (Team)
04 · Recent deals
No dated deals found yet.
05 · Latest from the firm
No news from the firm's website yet.
06 · Sources
- https://westlakebio.com/contact/
- https://westlakebio.com/people/
- https://westlakebio.com/about/
- https://westlakebio.com/portfolio/
Fund dates and sizes are from SEC Form D filings.
Last verified: Oct 28, 2026