About This Fund
Frazier Life Sciences XII, L.P. (FLS XII) is a $1.3 billion venture capital fund managed by Frazier Life Sciences, a Palo Alto-based investment firm specializing exclusively in biopharmaceuticals and life sciences. Founded with its first dedicated venture fund in 2016, the firm has grown into one of the most active life sciences venture investors in the United States, consistently backing company creation and early-stage private biotech and pharmaceutical programs. Fund XII is Frazier's largest vehicle to date, representing more than a 30% increase over its predecessor, Frazier Life Sciences XI ($987 million, 2022 vintage), and doubling the $617 million raised for Fund X in 2020.
FLS XII focuses on company creation and early-stage investment in private biopharmaceutical companies developing novel therapeutics to address significant unmet medical needs. The fund pursues opportunities at the company creation, seed, and Series A stages, working closely with founding teams to transform early-stage science into clinically validated programs. Frazier Life Sciences operates from four major U.S. biotech hubs — Palo Alto (headquarters at 1001 Page Mill Road), San Diego, Seattle, and Boston — providing broad geographic deal origination across the principal centers of biopharma innovation in North America.
Frazier Life Sciences XII held its final close on July 31, 2025, having raised over $1.3 billion in capital commitments from a mix of longstanding and new limited partners, closing oversubscribed relative to its initial target. The fund's oversubscription reflects sustained institutional confidence in Frazier's company-creation model at a time when investors have become more selective about early-stage life sciences exposure. In 2024, the firm was among the most active venture investors in private life sciences companies, participating in 17 private company financings. Managing Partner Patrick Heron leads the firm's investment team, which pursues a disciplined thesis centered on proprietary company creation alongside externally sourced early-stage opportunities.