Until Labs Closes $58 Million in Series A

Until Labs, the company developing reversible cryopreservation for patients in need of donor organs, led by Hunter Davis and Laura Deming, has secured $58 million in Series A, led by Founders Fund, with Lux Capital and Field Ventures joining, to support the development of an organ cryopreservation product.

Organ donation is extremely time-sensitive, hearts, lungs, and livers remain viable for 4–12 hours, and kidneys for 24–36 hours (Donor Alliance). Patients must stay near transplant centers, and surgeons often charter planes to retrieve organs, yet thousands are lost each year due to logistical delays or a lack of timely matches. In 2024, of ~106,000 patients on the waitlist, only ~46,000 received organs (HRSA), and many with advanced organ failure are never listed due to strict criteria or limited resources. Reversible cryopreservation could ensure every viable donated organ has the potential to save a life.

Until develops novel molecular agents, perfusion and surgical protocols, and cooling and rewarming hardware to enable reversible cryopreservation of biological systems. Research began with slices of neural tissue and has progressed to preclinical model organs. These milestones not only provide near-term solutions for patients but also lay the foundation for long-term whole-body medical hibernation technology.

Over the past year, a cryoprotective agent (CPA) discovery engine was established, a custom electromagnet was built, testing protocols were scaled to large animal organs, and multiple methods were developed to reduce cooling time. Current efforts focus on protocols that preserve organ quality post-cryopreservation.

The lab spans disciplines, and activities include simulating molecular dynamics, running high-throughput benchtop assays, mapping vasculature, exploring high-voltage electromagnet physics, and designing optimized heat exchangers. Perfusion experts and molecular biologists collaborate closely with hardware engineers and physicists.