C-Stem™ outperforms 2D & aggregate cultures in benchmark of cell culture technologies for the mass-production of human induced pluripotent stem cells

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TreeFrog Therapeutics presents new data at the 24th Annual Meeting of the American Society for Cell & Gene Therapy. 

Bordeaux, France  May 11, 2021One month after announcing  unprecedented exponential amplification of human pluripotent stem cells (hiPSCs) in a 10L bioreactor French cell therapy company, TreeFrog Therapeutics, today released previously unpublished data at the 24th Annual Meeting of the American Society for Cell & Gene Therapy. The findings compare the continuous expansion over 28 days of human induced pluripotent stem cells (hiPSCs) in 2D cell culture, aggregate culture in bioreactor, and bioreactor-based C-Stem™ technology. The benchmark demonstrates that C-Stem™ outperforms both the 2D and aggregate cell cultures, with a cumulated amplification of over 15millionfold over 28 days, achieved in only four passages.

A scalable approach to overcome the limitations of 2D cell culture 

With a 151 millionfold cumulated amplification, C-Stem nearly doubles the performance of 2D culture. 

Traditionally, pluripotent stem cells are grown in 2D, at the bottom of Petri dishes,” said Maxime Feyeux, co-founder and Chief Scientific Officer of TreeFrog Therapeutics. And while 2D enabled the launch of the first trials with iPS-derived therapeutic cells, this technology now constitutes a critical bottleneck for cell therapy manufacturing because of its inherent limitations in scaling. 2D cell culture is expensive and lacks reproducibility at a commercial scale because of the labor, time, and space it requires. For instance, to produce the batch of 15 billion cells that we recently announced, it would require ramping to full-time staff over 2 weeks and hundreds of Petri dishes, whereas it took us 2 staff for less than a week and a single 10L bioreactor with C-Stem.  

Scale-up in bioreactors – C-Stem™ leapfrogs aggregate culture  

Over 28 daysa 13,330-fold amplification was observed with hiPSC aggregates in bioreactors, with six passages, while 151 millionfold amplification was obtained with C-Stem in four passages.  

“I believe two core factors explain such a difference in yield,” said Kevin Alessandri, co-founder and Chief Technical Officer of TreeFrog Therapeutics. “On the one hand, our cell encapsulation technology is protecting the cells from impeller-induced shear stress in bioreactors, therefore limiting in-process cell death. On the other, the biomimetic microenvironment that we engineered inside the capsule allows hiPSCs to self-organize into an empty-core epiblast-like structure promoting fast and high-fidelity cell division, thus contrasting with the necrotic core found in aggregates.  

Benefits in genomic quality to be further investigated 

The benchmark data shows that final cell viability and pluripotency are comparable across the different cell culture systems. 

However, our preliminary results suggest that C-Stem is the only technology with the potential of maintaining genomic integrity throughout large-scale hiPSC expansion,” said Feyeux. In the coming months, we’ll investigate the benefits of C-Stem with the QC-Stem Consortium, which brings together experts in clinical- grade hiPSC quality control from the Harvard Stem Cell Institute in Boston, USA, the FBRI in Kobe Japan, and the Imagine Institute in Paris, France. 

About TreeFrog Therapeutics 

TreeFrog Therapeutics is a startup company aiming at providing access to cell therapies for millions of patients. TreeFrog Therapeutics has developed
Stem, a high-throughput cell encapsulation technology allowing for the mass-production and differentiation of stem cells in industrial bioreactors. This proprietary technology platform provides an end-to-end and scalable solution that dramatically improves the quality of therapeutic cells and reduce treatment costs. 

Since its incorporation in November 2018 in Bordeaux, France, TreeFrog Therapeutics has experienced strong acceleration, raising over €13M ($15.60M) in 2019. In January 2020, TreeFrog Therapeutics joined the FrenchTech120, an elite programme for the fastest-growing technology companies in France. The teamcurrently 40+ employeesmoved into a brand-new production facility of 13,000 sq ft in June 2020. In October 2020, TreeFrog Therapeutics was awarded the Prix Galien MedStartup for its international consortium on iPSC quality with the Harvard Stem Cell Institute, the FRBI in Kobe (Japan) and the Imagine Institute in Paris (France).  


European Commission

TreeFrog Therapeutics is receiving funding from the European Union’s Horizon 2020 research and innovation program through the SME Instrument Phase 2 under grant agreement n° SME 881113.

Press Contacts

TreeFrog Therapeutics
Pierre-Emmanuel Gaultier – pierre@treefrog.fr – +336 4577 4258

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