Treefrog Therapeutics, the EIC Accelerator and Stem Cells at Scale

Cell therapies that replace lost brain, liver or pancreas cells need billions of cells per batch, and stem cells are notoriously hard to grow in that quantity. TreeFrog Therapeutics, incorporated in Bordeaux in November 2018, puts human induced pluripotent stem cells (iPSCs) inside hollow alginate capsules, about a thousand per second, and grows them in ordinary stirred-tank bioreactors. In June 2019 the European Commission selected the company in the last round of the EIC SME Instrument Phase 2, and CORDIS records an EU contribution of €2,367,998 towards C-stemGMP, a €3,382,855 project to make that process compliant with good manufacturing practice (GMP), the standard for producing medicines for patients.

Seven years on, the record is mixed in a specific way. The GMP machine exists, but arrived a year after the project ended. Vertex Pharmaceuticals licensed the platform for its type 1 diabetes cell therapies in 2024, and the EIC picked TreeFrog again in October 2024, this time for equity only. Yet TreeFrog's own lead therapy, for Parkinson's disease, has not reached a patient: the first-in-human trial promised for 2024 is now planned for 2027, and the company's 2025 accounts show a loss of €21.2 million and equity below zero.

Where TreeFrog Stands Now

TreeFrog is active and still private. The French company register lists it as an active simplified joint-stock company (SAS) with Mark Rothera as president, Ernst & Young as auditor and three open establishments, and puts its workforce in the 100 to 199 band for 2024, according to the government's company search service. Its 2025 accounts were filed and announced in the official gazette on 9 July 2026, and the gazette records no insolvency proceedings, according to BODACC. North Data shows the same president and a share capital unchanged at €162,640 since October 2023.

The top of the company changed in December 2025. Mark Rothera, previously chief executive of Orchard Therapeutics, Silence Therapeutics and Viracta, succeeded Frédéric Desdouits after five years, and the co-founders Kévin Alessandri and Maxime Feyeux moved from daily operations to the board, the company announced; the search firm Coulter Partners confirmed the placement in January 2026. In May 2026 TreeFrog presented new preclinical data for TFG-001 at the World Parkinson Congress and said the therapy "will be ready for a Clinical Trial Application (CTA) in 2027", according to its release, also carried by BioSpace.

The Technology: Stem Cells in a Shell

iPSCs are adult cells reprogrammed into a stem-cell state, from which neurons, liver cells or insulin-producing islet cells can be grown. Most producers grow them as flat layers on plastic or as free-floating clumps, which TreeFrog's CORDIS report calls the "2D" and "aggregates" methods. TreeFrog argues that flat cultures can only scale out, flask by flask, and that clumps suffer from the shear of a stirred tank. C-Stem uses microfluidics to wrap small groups of cells in porous alginate capsules; inside, the cells organise into a hollow 3D structure that the company says mimics their natural niche, while the shell protects them from the impeller, according to TreeFrog's 2022 release with its equipment partner Invetech.

The company's own benchmark, run with the results of the EU project, claimed "a yield 5 times higher" than other methods with better control of mutations, according to the CORDIS periodic report. In 2021 TreeFrog announced that it had grown 50 million cells into a single batch of 15 billion in 6.5 days in a 10-litre bioreactor, according to its release. These are company figures; no independent replication was found.

The same capsules shape the product. According to TreeFrog, rival Parkinson's cell therapies transplant single-cell suspensions, while it transplants small pre-formed 3D microtissues of dopamine neurons and their progenitors. In rat models it reports dopamine release after 48 hours, against about 28 days reported for benchmark therapies, and motor recovery in about 13 weeks, against 17 to 28 weeks, according to the May 2026 release. These are preclinical results; no safety or efficacy data in humans exist yet.

What C-stemGMP Promised, and What the Record Shows

The June 2019 cut-off of the EIC SME Instrument Phase 2 lists "Treefrog Therapeutics", Bordeaux, as the sole beneficiary of C-stemGMP, according to the Commission's list of selected companies; no partner company is named. The grant agreement was signed on 28 November 2019, and the project ran from 1 November 2019 to 31 October 2021. Its objective on CORDIS was to "develop a GMP encapsulation device, to replace non-compliant materials, while developing relations with EU/US regulatory agencies and clients from the pharmaceutical industry" within 24 months. When TreeFrog announced the grant in September 2019 it went further, aiming "to deliver its first clinical-grade batches by 2021" and to supply them to partners by the first quarter of 2021, according to its release.

The final periodic report says that, with Invetech, the company built "a functional and fully integrated encapsulator prototype", brought the production of its microfluidic glass chips in-house and "validated the use of GMP compatible compounds throughout its process". It did not report a finished GMP device. Invetech had delivered a research-grade beta system in April 2020, and in October 2020 the two companies set a new goal of a GMP-compliant device "by the end of 2022", according to their partnership release. The GMP-grade machine was delivered in October 2022, almost a year after the EU project closed; Desdouits called it "right on time" against the 2020 plan.

1. GMP encapsulation device within 24 monthsLateDelivered by Invetech in October 2022, a year after the project ended.
2. Replace non-compliant materialsDeliveredGMP-compatible compounds validated, per the CORDIS report.
3. Pharmaceutical clientsDeliveredExclusive C-Stem licence to Vertex for type 1 diabetes, April 2024.
4. Relations with EU and US regulatorsNot achievedNo regulatory filing announced; the first trial application is planned for 2027.
5. Clinical-grade batches for partners by 2021Not achievedNo clinical use of C-Stem material announced by October 2026.

The core of the grant, a machine that can make clinical-grade cells, was built, and the platform found a paying pharmaceutical partner. The regulatory and clinical side of the plan did not follow on the stated timetable: TreeFrog's own 2021 Series B announcement still targeted a first trial in 2024, and the date has since moved to 2027.

The Second Award: C-STEM XL

In October 2024 TreeFrog applied again, now under the Horizon Europe EIC Accelerator. The Commission's list for the October 2024 cut-off names "TREEFROG THERAPEUTICS" with C-STEM XL, "C-STEM : ground-breaking path to the XL scale", recommended for equity only. It was one of five equity-only selections among 71 companies chosen from 1,211 proposals, according to the EIC's announcement of 17 February 2025; Université Paris-Saclay also reported that TreeFrog "will receive an equity investment for the project C-Stem XL". No amount has been published, and CORDIS lists no C-STEM XL project.

What TreeFrog Has Achieved Since 2019

Private and public money followed the first grant. A €7.1 million Series A led by XAnge closed in May 2019, according to the company's release. In September 2021 TreeFrog closed a $75 million (€64 million) Series B led by Bpifrance Large Venture with Leonard Green & Partners, Bristol Myers Squibb and XAnge, bringing its total to $83 million, according to the company and Global Venturing. The company's boilerplate quoted "$82 million" raised in its releases from October 2022 to December 2025, and no new equity round has been announced since the Series B.

The biggest commercial step came in April 2024. Vertex took an exclusive licence to C-Stem to scale up its stem cell-derived islet cell therapies for type 1 diabetes; TreeFrog is to receive a $25 million upfront payment, an equity investment from Vertex, up to $215 million in process milestones and up to $540 million in further clinical, regulatory and commercial milestones, plus single-digit royalties, according to the joint release and BioPharm International. Whether any milestone has been paid, and the size of Vertex's equity stake, are not public. Earlier collaborations include the French Blood Agency (EFS) for blood stem cell grafts in 2020, Gaia BioMedicine in 2023 and the University of Pittsburgh in 2024, according to the company's news page; none has been reported as commercial revenue.

On the science side, TreeFrog published in 2024 what it called the first bioproduction of a Parkinson's cell therapy in a scalable bioreactor, with full behavioural recovery in rats 16 weeks after transplanting cryopreserved microtissues, according to its release on the Neurotherapeutics paper. Its pipeline page lists TFG-001 for Parkinson's, TFG-002 for liver disease and an undisclosed TFG-003, all before clinical trials.

The Money

TreeFrog's accounts for 2020 and 2021 were filed confidentially, according to BODACC. From 2022 they are public. Revenue was about €0.5 million in 2022 and 2023, then €22.55 million in 2024, the year of the Vertex deal, and €19.20 million in 2025. Net losses were €10.08 million in 2022, €23.44 million in 2023, €17.22 million in 2024 and €21.25 million in 2025, according to the INPI ratio data published on data.economie.gouv.fr; the government's company search service gives the same 2025 revenue and result. The accounts summary does not split revenue by source.

The same INPI data show the balance sheet weakening each year: equity fell from 83.4% of total assets in 2022 to 27.3% in 2024 and to minus 8.9% at the end of 2025, which means liabilities exceeded assets. This figure comes from one dataset and could not be checked against the full filed accounts for this article.

The main new money since the Series B is debt-like. In May 2025 the European Investment Bank agreed €30 million in three €10 million tranches, the first two as dilutive financing with no principal repayment and the third as venture debt, backed by an InvestEU guarantee, to bring TFG-001 to a first trial in 2027, according to the EIB and Impact Investor. Sources differ on how much was drawn: the EIB said the first €10 million would be drawn in the second quarter of 2025, while FrenchWeb reported on 28 May 2025 that the first two tranches had "already been paid" and that the third depends on trial results. FrenchWeb also reported that a new fundraising was being prepared; none has been announced since.

Why Europe Should Care

TreeFrog's field sits at the centre of EU health biotech policy. On 16 December 2025 the Commission proposed a European Biotech Act aimed at health biotechnology, which would cut clinical trial approval times and remove the extra 50 days of assessment for advanced therapy medicinal products (ATMPs), the legal category for cell therapies, according to Crowell & Moring. The Commission's case, as summarised by Morgan Lewis, is that "only 7% of global venture capital investment in health biotech is in the EU" and that Europe's share of commercial clinical trials fell from 22% to 12% in a decade.

TreeFrog shows both sides of that problem. EU institutions have backed it three times, with the 2019 grant, the 2024 EIC selection and the 2025 EIB financing, yet its largest commercial deal so far licenses a European manufacturing technology to a US group for its type 1 diabetes therapies, and its own first clinical trial is not planned before 2027.

The Verdict

TreeFrog Therapeutics, Vertex and the EIC have not been asked for comment for this article. It is based on public records, company statements and EU project data, linked throughout.