RougeTx Raises $58 Million Series A for HHT Drug RTX-001

RougeTx has closed a $58 million Series A financing to advance RTX-001, a once-daily oral small-molecule candidate for hereditary hemorrhagic telangiectasia (HHT), toward first-in-human testing. The Naarden, Netherlands company announced the round on 6 October 2026, co-led by BioGeneration Ventures, Angelini Ventures and Kurma Partners alongside the European Investment Bank’s Aurea co-investment facility — financing that doubles as RougeTx’s public launch, more than two decades after the pericyte research behind RTX-001 began in Franck Lebrin’s laboratory.

Twenty years of pericyte research, one Naarden address

RougeTx’s origin sits almost entirely inside one scientist’s career. Franck Lebrin, an associate professor at Leiden University Medical Center with a parallel post at Inserm in Paris, has spent more than two decades studying pericytes — the mural cells that wrap around blood vessels and keep them from leaking or rupturing. In a 2015 review in Frontiers in Genetics, Lebrin and co-authors Jérémy Thalgott and Esther Dos Santos Luís argued that HHT’s bleeding and malformed vessels trace back to pericytes losing their grip on vessel walls, and that drugs capable of restoring that attachment — rather than simply blocking blood-vessel growth — could be a therapeutic route the field had largely passed over.

RougeTx, co-founded by Lebrin and Thalgott as a spin-off of Lebrin’s LUMC laboratory, turns that research into RTX-001, its sole disclosed program. The company had not previously announced a funding round; the $58 million Series A and RougeTx’s public launch were announced together on 6 October 2026.

The lab-to-launch stretch

1. 2015

   Pericytes named as an HHT target

   Franck Lebrin, Jérémy Thalgott and Esther Dos Santos Luís publish a review in Frontiers in Genetics arguing that restoring pericyte attachment to blood vessels — not only blocking new vessel growth — is a route to treating HHT.

2. 6 October 2026

   RougeTx launches with $58M Series A

   RougeTx announces its public launch alongside a $58 million Series A, co-led by BioGeneration Ventures, Angelini Ventures and Kurma Partners with the European Investment Bank's Aurea facility.

3. Ahead

   First-in-human testing

   RougeTx says the financing is meant to carry RTX-001 into first-in-human studies. Several outlets reporting on the launch describe the company's stated plan as a double-blind, placebo-controlled Phase IIa study in HHT patients, though no trial registry entry, start date or Phase I safety data have been published.

Three co-leads, five funds, one pericyte

The round’s structure says something about how its backers are reading RougeTx’s risk. BioGeneration Ventures — described by the company’s own backers as RougeTx’s founding investor — co-led alongside Angelini Ventures, the venture arm of Italy’s Angelini Industries, and Kurma Partners, a Eurazeo-affiliated life-sciences fund, with the European Investment Bank’s Aurea co-investment facility also in the lead group. Epidarex Capital, Vesalius Biocapital Partners, ROM Utrecht Region, p53 Invest and Kerna Ventures joined as participants. Reporting on the round names Angelini Ventures’ Regina Hodits and BioGeneration Ventures’ Edward van Wezel among the investor representatives joining RougeTx’s board.

RougeTx has said the proceeds are meant to fund an evaluation of RTX-001’s safety and efficacy in what the company has described — in wording reported in close to identical form across several outlets — as a well-powered, double-blind, placebo-controlled Phase IIa study in HHT patients. That description has not been corroborated by an independent trial registry entry, and a Phase IIa study would ordinarily follow, not substitute for, an earlier Phase I safety read in humans, which RougeTx has not disclosed. The company has also said the financing supports periSCOPE, an internal platform for identifying further small-molecule candidates in other diseases where vessel instability plays a role.

RTX-001, measured four ways

$58MSeries A, announced 6 October 2026

1 in 5,000estimated HHT prevalence, the ceiling used in HHT’s EU orphan-drug designations

0FDA- or EMA-approved disease-modifying therapies for HHT today

20+years of pericyte research behind RTX-001, from Lebrin’s labs at Inserm and LUMC

Financing figures from the 6 October 2026 announcement; prevalence from the European Medicines Agency’s orphan designations for HHT treatments.

Reattaching the cells vessels lean on

Most drug strategies tried against HHT attack blood-vessel growth itself: bevacizumab and other anti-VEGF agents try to starve abnormal vessels of the signal that lets them form and bleed. RougeTx’s approach, built on Lebrin’s pericyte research, targets something different — the structural support that keeps a normal vessel from leaking in the first place. Pericytes are the cells that wrap around capillaries and small vessels, and in HHT, caused by mutations in genes including ENG, ACVRL1 and SMAD4 that disrupt TGF-β/BMP signaling, pericytes fail to properly attach to vessel walls, leaving the tangled, fragile connections — telangiectases and arteriovenous malformations — that bleed. RTX-001 is designed as an oral small molecule meant to restore that attachment rather than block vessel growth outright.

RougeTx has said the biology behind RTX-001 may extend past HHT to other diseases where vessel instability plays a role, and that the Series A also funds periSCOPE, a platform built to pursue that broader pipeline. For now, RTX-001 is the company’s only disclosed candidate, and it has not yet been dosed in a person.

Three bets behind RTX-001

01

A pill, not an infusion or injection

RTX-001 is oral and once-daily by design. Bevacizumab is given by intravenous infusion, and the two most advanced HHT competitors with human safety data so far — Diagonal Therapeutics’ DIAG723 and Tectonic Therapeutic’s TX2100 — are both delivered by subcutaneous injection.

02

Structure, not just signaling

Where bevacizumab and Vaderis Therapeutics’ engasertib work by blocking growth-factor or kinase signaling, RougeTx is betting that reattaching pericytes to the vessel wall addresses HHT’s structural cause directly — a mechanism built on Lebrin’s two decades of mural-cell research rather than repurposed oncology biology.

03

A syndicate before a single dose

Three co-lead funds and the European Investment Bank’s Aurea facility backed RTX-001 before it has been tested in a person — a deeper syndicate than a typical Series A, assembled around preclinical data alone.

A bleeding disorder still waiting on a label

HHT, also called Osler-Weber-Rendu syndrome, is an autosomal dominant genetic disorder that leaves blood vessels throughout the body prone to forming fragile, tangled connections. Estimates of how many people have it vary with the method: a 2024 genomic-database analysis and several clinical reviews put prevalence at roughly 1 in 5,000, a UK primary-care study found at least 1 in 9,500, and Vaderis Therapeutics — one of RougeTx’s prospective competitors — cites roughly 1 in 3,800 in its own materials; the European Medicines Agency’s orphan-drug designations for HHT treatments use a ceiling of no more than 2 in 10,000 people in the EU. By most accounts it is the second most common inherited bleeding disorder after von Willebrand disease, and the sources that disagree on its exact prevalence agree on one point without qualification: no drug holds FDA or EMA approval specifically for HHT.

“HHT is the second most common genetic bleeding disorder, yet patients are still awaiting an approved drug.” Andrew Lightfoot, Chief Executive Officer, RougeTx — quoted by European Biotechnology Magazine’s BioXconomy, 6 October 2026

Care today is built around managing bleeding rather than treating its vascular cause. Recurrent nosebleeds are typically managed with moisturizing nasal therapies, oral tranexamic acid, cautery, nasal packing or laser treatment; chronic blood loss is managed with iron supplementation or intravenous iron infusion — the FDA has flagged HHT as a risk factor for low blood phosphate on at least one iron-infusion label — and, in severe cases, transfusion. Where drugs are used against the bleeding itself, it is off-label: bevacizumab, an anti-VEGF antibody approved for cancer, showed improved hemoglobin and epistaxis scores in an observational study of 238 patients, and pomalidomide, an immunomodulatory drug, improved nosebleed scores against placebo in a 144-patient randomized trial published in the New England Journal of Medicine in 2024 — evidence stronger than bevacizumab’s, but still short of what either drug’s own regulatory label covers.

What $2.43 billion by 2035 would require

$0.62B → $2.43B

Global HHT disease market, 2024 actual to 2035 forecast, per Market Research Future (May 2026).

2024$0.62B

2025$0.71B

2035$2.43B

Sources: Market Research Future, Hereditary Hemorrhagic Telangiectasia Disease Market

Regulatory News outlook

No published forecast yet prices in an approved HHT drug, because none exists; Market Research Future’s $2.43 billion 2035 figure describes a market still built mostly from supportive care. Using the prevalence ceiling behind HHT’s EU orphan designations, we estimate no more than about 157,000 people have HHT across the U.S. and EU combined — a ceiling, not a forecast, since most cases are mild or undiagnosed and would never need a systemic drug.

How we got here: Roughly 1-in-5,000 prevalence (the ceiling used in HHT’s EU orphan-drug designations) × a combined U.S. (~335 million) and EU (~450 million) population of ~785 million ≈ 157,000 people with HHT in those two markets. Applying a representative orphan-drug price of roughly $150,000 a year to just 10% of that population — a plausible share with bleeding severe enough to need a systemic drug — implies peak annual sales on the order of $2.4 billion for a single approved HHT therapy in the U.S. and EU alone, before splitting that population across every program named in this article; by coincidence, that figure lands close to Market Research Future’s own 2035 estimate above.

RTX-001 against four rivals already in people

Program	Mechanism	Route	Stage	Regulatory status
RTX-001 (RougeTx)	Restores pericyte attachment to vessel walls	Oral, once-daily	Preclinical	No filing yet
Engasertib / VAD044 (Vaderis Therapeutics)	Allosteric AKT1/2 inhibitor	Oral, once-daily	Phase 3 (HEROIC)	Not approved
DIAG723 (Diagonal Therapeutics)	Clustering-agonist antibody restoring ALK1 signaling	Subcutaneous	Phase 1/2 (DIAMOND)	Not approved
Bevacizumab (off-label)	Anti-VEGF monoclonal antibody	IV infusion	Approved for cancer; used off-label in HHT	Not approved for HHT
Pomalidomide (off-label)	Immunomodulatory, antiangiogenic	Oral	Tested in a randomized trial (NEJM, 2024)	Not approved for HHT

From each company’s own announcements and labelling, and the cited peer-reviewed literature; not a head-to-head clinical comparison.

Four rivals already in clinic, one still in a dish

RougeTx is not entering an empty field, even though HHT has no approved drug. Vaderis Therapeutics closed a $152 million Series B in August 2026 and started HEROIC, a global Phase 3 trial of its oral AKT inhibitor engasertib, built on proof-of-concept data already published in the New England Journal of Medicine. Diagonal Therapeutics dosed the first patient in a Phase 1/2 trial of its antibody DIAG723 in July 2026. Tectonic Therapeutic reported favorable Phase 1a safety and pharmacokinetic data for its antibody TX2100 in September 2026 and holds an FDA Fast Track designation. Atavistik Bio is partnering with the patient group Cure HHT on an early-stage study of its oral candidate ATV-1601. Each is further along than RTX-001, which remains preclinical.

That gap is the honest read of this financing: $58 million is a well-backed start, not a trial result. What RougeTx has not yet published — a first-in-human start date, a registered trial, or Phase I safety data — is exactly what separates it from the four competitors above. The company’s own statements point toward a Phase IIa study; reaching it will require disclosing the steps in between.

• No trial registry entry yet: RougeTx has not published a start date, design or registry record (ClinicalTrials.gov or an EU clinical trials register) for RTX-001’s first human study.
• Phase IIa, without a disclosed Phase I: company materials reported in similar form across several outlets describe a planned double-blind, placebo-controlled Phase IIa study; no Phase I safety data in humans has been published.
• Round split undisclosed: RougeTx has not broken out how the $58 million divides among its three co-lead funds, the EIB’s Aurea facility and its five participating investors.
• A late entrant to a field already dosing patients: Vaderis, Diagonal, Tectonic and Atavistik Bio all have HHT candidates already tested in humans.

Frequently asked questions

What is RTX-001 and how is it meant to work?

RTX-001 is RougeTx's lead program: an oral, once-daily small molecule designed to stabilize fragile blood vessels by restoring the attachment of pericytes, the support cells that wrap vessel walls. It is intended for hereditary hemorrhagic telangiectasia (HHT) and remains in preclinical testing; it has not yet been dosed in a person.

Is there an FDA- or EMA-approved treatment for HHT?

No. HHT has no drug approved specifically for it by the FDA or EMA. Care today centers on managing bleeding — nasal therapies, tranexamic acid, cautery, laser treatment, iron supplementation or infusion, and transfusion — plus off-label use of drugs such as bevacizumab and pomalidomide.

Who backed RougeTx's Series A, and what is it for?

The $58 million round, announced 6 October 2026, was co-led by BioGeneration Ventures, Angelini Ventures and Kurma Partners together with the European Investment Bank's Aurea co-investment facility. Epidarex Capital, Vesalius Biocapital Partners, ROM Utrecht Region, p53 Invest and Kerna Ventures also participated. RougeTx says the money will carry RTX-001 toward first-in-human testing and fund periSCOPE, a platform for identifying further vascular-disease candidates.

Is RougeTx the only company developing an HHT drug?

No. Vaderis Therapeutics' engasertib is already in a global Phase 3 trial, Diagonal Therapeutics and Atavistik Bio each have Phase 1/2 studies underway, and Tectonic Therapeutic has reported Phase 1a data for its candidate. RTX-001, by contrast, remains preclinical.