ReFOLD Bio

Who We Are

An emerging venture, rooted in world-class science

ReFOLD Bio is a pre-incorporation venture being developed by a team of scientists and entrepreneurs based at the Princess Máxima Center and UMC Utrecht. We are in the process of spinning out our technology into a dedicated company, with the support of our institutional partners and early backers.

Our scientific foundation was built within the Princess Máxima Center for Pediatric Oncology, Oncode Institute, and UMC Utrecht — three of the Netherlands' leading research institutions. We are developing ReFOLD's programs in close partnership with these institutes, and will maintain that relationship through incorporation. The technology advances their research missions. The patients benefit from faster translation.

We aim to make gene editing therapy available to all patients suffering from protein folding diseases — starting with the most urgent unmet needs, and expanding across a growing class of misfolding indications.

Status

Pre-incorporation venture · Spinout in progress from the Princess Máxima Center, Oncode Institute and UMC Utrecht

Stage

Early scientific validation · First proof-of-concept data generated · Preparing seed funding round

The Science

A revolutionary approach to genetic disease

Hundreds of millions of people live with diseases caused by a single misfolded protein. Gene editing therapy promises a one-time, durable fix. The tools now exist — base editors make precise, single-letter DNA changes without cutting the genome. What the field lacks is a reliable way to find the right targets, validated in the cells that actually matter. That is what ReFOLD does.

A new target space

Current base editors can only correct a limited subset of mutations, leaving the majority of disease-causing variants — deletions, transversions, complex indels — unreachable. ReFOLD's unique approach circumvents this limitation and enables restored protein function without touching the original mutation, thereby expanding the addressable patient population to groups currently excluded from any gene editing pipeline.

Validated where it counts

Discovery and validation are performed directly in patient-derived stem cells — the same cell types that gene editing therapy must ultimately correct. Conventional target discovery in immortalised cell lines produces candidates that fail at high rates when advanced into more relevant systems. ReFOLD targets arrive with functional evidence from disease-relevant human tissue models, substantially reducing translation failure risk.

First proof of concept: Cystic Fibrosis

CF is ReFOLD's lead program. With a large patient population currently ineligible for gene editing therapy and a multi-billion dollar market dominated by lifelong small-molecule treatment, CF represents an ideal first demonstration of the ReFOLD platform. Early screening experiments in patient-derived stem cell models have already yielded promising functional results, providing initial proof-of-concept for the approach.

A proven market for what we build

Large pharmaceutical companies pay substantial sums for validated gene editing targets. Pfizer committed ~$300M upfront to Beam Therapeutics; Vertex paid over $900M upfront to CRISPR Therapeutics. ReFOLD is positioned to deliver the same calibre of partner-ready data packages — novel targets, functional rescue data, and genome-wide safety profiles — beginning with Cystic Fibrosis. Our functional rescue and safety profiling data is generated using established primary stem cell models — no patient data from clinical care is involved.

Technology

Three integrated capabilities

Our end-to-end discovery platform generates clinically actionable editing targets — with functional validation and genome-wide safety profiles built in from day one.

Screen

Proprietary base-editing screens systematically identify intragenic suppressor mutations across entire coding sequences. Screens run directly in patient-derived cells using optimised RNP delivery — achieving editing efficiencies in primary human models that exceed those reported elsewhere in the current literature.

Validate

Functional readouts in clinically relevant stem cell models confirm protein rescue in physiological context. Performing discovery and validation in the same disease-relevant cells dramatically increases the likelihood of downstream clinical success — and is, to our knowledge, unique at this scale in the field.

Partner

We deliver partner-ready data packages: validated guide RNA sequences with demonstrated functional rescue, editing efficiency data from disease-relevant human models, and a genome-wide safety profile confirming absence of off-target effects. Partners bring delivery expertise; we bring the target.

The Team

Built to cure. Designed to scale.

Maarten Geurts, PhD

Inventor of the ReFOLD principle. Deep expertise in CRISPR base editing and RNP delivery in stem cells. Postdoctoral researcher at the Princess Máxima Center, trained by Georg Church and David Lui.

Else Driehuis, PhD

Translational scientist and biotech operator (PhD, Hans Clevers lab). Former Site Head & Sr Director at Xilis BV — built the Dutch R&D site from scratch, scaling to 13 FTE over 3 years.

Ruben van Boxtel, Prof.

Professor of genetics at UMC Utrecht & the Princess Máxima Center. World-leading expert in genome stability and off-target safety assessment. Trained by Mike Stratton & Edwin Cuppen.

Jeffrey Beekman, Prof.

Professor at UMC Utrecht. Inventor of the CF swelling assay and other clinically relevant organoid models and assays. Pioneer in stem cell model-based functional assays for genetic disease.

Pioneeringprotein foldingtherapeutics