South San Francisco longevity biotech NewLimit has raised $435 million in a Series C funding round at a $3.1 billion post-money valuation, tripling its worth in roughly a year and clearing the way for the company's first clinical trial in 2027.
One of biotech's biggest private rounds of 2026
The financing was led by Founders Fund, the Silicon Valley venture firm co-founded by Peter Thiel, joined by returning backers Kleiner Perkins, Eli Lilly Ventures and Human Capital alongside new investors Thrive Capital, Greenoaks and Quiet Capital. Tech entrepreneurs Nat Friedman and Daniel Gross also participated. The round caps a year that has also seen mega-rounds in adjacent fields, from AI foundation models to physical-AI robotics.
From screening platform to clinic-ready drug
NewLimit was founded in 2021 by Coinbase CEO Brian Armstrong, former GV partner Blake Byers and stem-cell biologist Jacob Kimmel, who serves as CEO. The team built a screening platform to find combinations of transcription factors — proteins that switch genes on and off — capable of rejuvenating specific cell types. Kimmel told Fierce Biotech the company expected the process to take three to four years, but its first liver candidate emerged in months.
How the liver therapy works
The lead candidate is fewer than ten transcription factors packaged as mRNA inside a lipid nanoparticle. Delivered intravenously, the mRNA instructs old liver cells to express younger-state proteins, reversing decline. In preclinical models, treated old mice tolerated alcohol like young ones; the planned Phase 1 trial will recruit patients with fatty liver disease, before NewLimit moves into a Phase 2 focused on alcohol-related liver disease.
A bigger pipeline beyond the liver
Flush with cash, NewLimit's 50-person team is now finalising transcription-factor combinations for endothelial cells in blood vessels (with chronic kidney disease as a target) and for T cells, where Kimmel hopes to improve immune function in conditions such as rheumatoid arthritis. Initial dosing is expected to be monthly IV infusion.
Longevity goes mainstream — with caveats
The round arrives as longevity transitions from fringe pursuit to one of biotech's most-funded sub-sectors, though Kimmel acknowledged the field has long been marred by "over-salesmanship and a lack of rigorous science." The deep-pocketed Series C, he said, lets NewLimit bring "the same rigorous, deeply scientific approach" seen elsewhere in biotech to age-related disease.
Reporting based on coverage from STAT News (Allison DeAngelis, 2 June 2026), Fierce Biotech and Endpoints News.