Published on
September 4, 2025
Revalia Bio's Human Data Trials
Bringing a new medicine to market is one of the most expensive and time-consuming processes in healthcare. Despite the investment, over 90 percent of drugs fail in clinical trials. The core issue is a lack of predictive, human-relevant data at the earliest stages of development.
Revalia Bio is changing that. The company enables the direct testing of drug candidates on functional human organs outside the body, under clinical conditions. These Human Data Trials give researchers a way to evaluate safety, efficacy, and mechanism using real human biology — before a single patient is enrolled in a traditional clinical trial.
Revalia’s platform combines decades of innovation in organ perfusion science with powerful software that integrates patient history, real-time organ function, and analytical insights. The result is a new foundation for drug development — one that reduces risk and gives drug developers faster, clearer answers.
Since launching, the team has made fast progress. They've built meaningful traction with top pharmaceutical companies and developed first-of-their-kind models, including a four-day kidney perfusion protocol and an early-stage human lung cancer model.
Revalia is led by a group of scientists, engineers, and operators who have dedicated their careers to solving the translation gap between preclinical testing and human outcomes. The company is led by Greg Tietjen, PhD, a Yale professor and pioneer in organ perfusion science who left academia to focus on Revalia full-time. He’s joined by Jenna DiRito, PhD, who has built and scaled some of the most complex organ perfusion programs in the country, Peter Buniak, a biotech operator with over 20 years of experience driving innovation in life sciences, and Kourosh Saeb-Parsy, MD/PhD, a practicing transplant surgeon and professor at the University of Cambridge. This is a team with rare depth across science, clinical practice, and execution. Janet Nikolovski, Chief Data Officer, brings 20 years of experience at J&J, leading programs with proven success in bringing new products to market.
At Sierra Ventures, the next wave of healthcare innovation will come from technologies that unlock deeper human insight, earlier in the process. Revalia is a prime example of that shift — offering a powerful new toolset for drug developers and a clearer path toward better therapies for patients.
We’re proud to support their mission.