bit.bio closes $25M Series D to scale human cell models

Why human cell models are in demand

Drug discovery teams increasingly need experimental models that predict how a treatment will behave in people. Traditional animal models are limited by biological differences between species, which is pushing interest toward human cell-based alternatives that can support more relevant testing and reduce reliance on animal experiments.

Advances in AI add to the pressure. As software speeds up the identification and design of drug candidates, researchers need consistent, reproducible human cell models to assess safety and effectiveness.

The opti-ox platform

bit.bio's answer is its proprietary opti-ox™ platform, which produces defined human cell types consistently and at scale. The technology is meant to overcome donor variability and limited cell supply. Its ioCells portfolio already covers more than 50 human cell types, including models of the heart, liver and central nervous system, used in disease research, functional genomics, drug discovery and toxicology.

CEO Dr Emma Pepperell said the industry is reaching an inflection point: AI is changing how quickly medicines can be found, while the shift toward animal testing alternatives is raising demand for models that better reflect human biology. Both trends, she said, require vast quantities of consistent human cells, and investors believe bit.bio can supply them at scale.

With its manufacturing infrastructure already in place, the company plans to use the new capital to add more human cell types and make its models available to more researchers. It will focus on turning rising demand into commercial growth while supporting the development and testing of new medicines.