Westlake BioPartners Research
Investment Thesis
Westlake BioPartners (formerly Westlake Village BioPartners) is a Los Angeles-area life science venture capital firm built around a "people-first" philosophy: the firm believes it takes more than great science to build life-changing medicines, and prioritizes exceptional entrepreneurs and management teams over backing ideas alone. Their stated values are "Put People First," "It Takes a Village," "See It Through," "Be Engaged," and "Patients Are Our North Star." Rather than a passive check-writer, Westlake positions itself as a company-building partner that rolls up its sleeves alongside founders from ideation through commercial impact, frequently incubating companies directly rather than only investing in existing ones.
Sector Focus
Westlake invests exclusively in biotech and life sciences, spanning small-molecule, gene therapy, cell therapy, RNA medicine, and immunotherapy modalities. Represented therapeutic areas in the current portfolio include inflammatory and autoimmune disease, oncology/solid tumor cell therapy, pulmonary and fibrotic disease, neurology, migraine prevention, and genetically defined muscle and heart disease (Duchenne muscular dystrophy and related conditions).
Stage Focus
The firm invests across the full life-science company lifecycle, from ideation and preclinical research through clinical and commercial development, with a strong emphasis on incubating and leading Series A rounds for de novo biotech companies.
Check Size
Check size was not explicitly disclosed on the website. Observed round sizes the firm has co-led or led range from roughly $46M-$135M Series A financings, consistent with a life-science venture model that concentrates capital in a small number of companies per fund rather than spreading broadly. The firm describes itself as "intentionally scaled to incubate only the most promising companies."
Lead Tendency
Westlake frequently leads or co-leads Series A rounds, especially for companies it incubates directly (e.g., Latigo Biotherapeutics, Vedana Therapeutics, AllRock Bio).
Recent Activity
Westlake closed a $450M Fund III in July 2023 (announced alongside David Allison's promotion to Managing Director), bringing total assets raised since the firm's 2018 founding to approximately $1.3B. Recent financings include a $50M Series A co-led for AllRock Bio (September 2025, targeting pulmonary arterial hypertension) and a $46M Series A co-led for Vedana Therapeutics (June 2026, migraine prevention antibodies), both alongside co-investors such as Versant Ventures, Canaan Partners, Dawn Biopharma, and Alexandria Venture Investments.
Portfolio Highlights
Notable exits include Kate Therapeutics (acquired by Novartis for up to $1.1B including milestones, October 2024) and Kyverna Therapeutics (IPO on Nasdaq, February 2024, cell therapy for autoimmune disease). ACELYRIN, an earlier Westlake-incubated IPO, merged with Alumis Inc. in 2025 to form a late-stage clinical immunology company. Active portfolio companies include 3T Biosciences (TCR-based immuno-oncology target discovery), Capsida Biotherapeutics (AAV gene therapy engineering), Electra Therapeutics (SIRP-targeted immunology/oncology antibodies), Arsenal Biosciences (programmable cell therapy for solid tumors), Recludix Pharma (SH2-domain small-molecule inhibitors for inflammatory disease), Borealis Biosciences (RNA medicines for kidney disease), Latigo Biotherapeutics (non-opioid pain medicines, incubated by Westlake with 5AM Ventures and Foresite Capital), Neuron23 (precision medicines for genetically defined neurological and immunological disease), AllRock Bio (pulmonary hypertension), and Vedana Therapeutics (migraine prevention).
Team
- Beth Seidenberg, MD — Founding Managing Director; former General Partner at Kleiner Perkins; prior executive roles at Amgen, Merck Research Labs, and Bristol-Myers Squibb.
- Mira Chaurushiya, PhD — Managing Director; formerly Partner at 5AM Ventures; postdoctoral fellow at Genentech; PhD in Biological Sciences (UCSD/Salk Institute).
- David Allison, PhD — Managing Director; prior roles at 5AM Ventures, Versant Ventures, Split Rock Partners, and PTV Healthcare Capital; PhD in Bioengineering (Rice University).
- Jennifer Kercher, JD — General Counsel; formerly Chief Legal Officer/COO at Section32 and General Counsel at GV (Google Ventures).
- Desmond Padhi, PharmD — Operating Partner; 20 years at Amgen in clinical development VP roles.
- Brogan Perrelli, CPA — VP Finance & Operations; prior experience at KPMG, Crowe Horwath, and ICONIQ Capital.
- Lauren Popov, PhD — Associate; formerly Senior Director of Translational Biology at Novome Biotechnologies; PhD from Stanford School of Medicine.
- Armando Alvarez, CPA — Finance Manager; prior experience at PwC and The Walt Disney Company.
- Kelli McKeirnan — Director of Administration; 20+ years as an executive administrator at Amgen.
Decision Process
Investment decisions appear to run through the partnership (Seidenberg, Chaurushiya, Allison), consistent with a small, concentrated GP team model typical of specialist life-science incubator funds.
Founder Preferences
Westlake explicitly backs entrepreneurs first, frequently pairing experienced biopharma executives (many with Amgen, Genentech, or big-pharma pedigrees) with novel platform science, and often assembles founding teams itself as part of its incubation model rather than only responding to inbound pitches.
Geographic Focus
Headquartered in Westlake Village, CA, with an explicit mission to strengthen the Los Angeles-area life science ecosystem; portfolio companies are also located in the broader California biotech corridor (South San Francisco, Thousand Oaks) and the company has backed at least one Seattle-based team (Vedana).