RougeTx launches with $58m Series A to target HHT bleeding disorder
RougeTx, a preclinical-stage biotechnology company spun out of Leiden University Medical Center, has launched with a $58 million Series A financing to advance its lead programme, RTX-001, into first-in-human clinical development for hereditary haemorrhagic telangiectasia (HHT).
The round was co-led by BioGeneration Ventures (BGV), Angelini Ventures, and Kurma Partners, with the European Investment Bank's Aurea co-investment facility also taking part. Epidarex Capital, Vesalius Biocapital Partners, ROM Utrecht Region, p53 Invest, and Kerna Ventures participated alongside the lead investors. Five investor representatives will join the board in connection with the close.
The science and unmet need
HHT is the second most common inherited bleeding disorder. It is caused by defective formation of arteriovenous malformations, which produces fragile, unstable blood vessels prone to rupture. Patients experience recurrent nosebleeds and gastrointestinal bleeding, often developing iron deficiency and chronic anaemia as a result. In more severe cases, AVMs can affect major organs including the lungs, liver, and brain. Despite affecting an estimated one in 5,000 people globally, HHT has no approved disease-modifying therapies, and current management is almost entirely symptomatic or off-label.
RTX-001 is designed to address the underlying vascular pathology rather than its consequences. The candidate aims to restore pericyte attachment to blood vessel walls, thereby stabilising the fragile vasculature characteristic of HHT. Pericytes are the contractile cells that wrap around capillaries and small vessels to regulate their integrity; disruption of pericyte function is increasingly recognised as a driver of vascular malformation across several disease settings. The company intends to develop RTX-001 as a once-daily oral therapy, a formulation profile that would represent a practical advantage over the intravenous or interventional approaches patients currently rely on.
Andrew Lightfoot, chief executive of RougeTx, said the preclinical dataset generated so far provides "a strong foundation as we move toward the clinic," and that the financing also creates scope to explore whether the same pericyte biology has relevance in other vascular diseases.
Platform and competitive context
Beyond RTX-001, RougeTx is advancing what it calls its periSCOPE platform, which applies the company's vascular biology expertise to identify further small-molecule programmes in diseases driven by vascular instability. The company's co-founder and scientific adviser, Franck Lebrin, noted that the work draws on more than 20 years of research conducted initially at Inserm and latterly at Leiden University Medical Center.
HHT is a sparsely served orphan indication, and RougeTx will not face an established competitive field in the approved-therapy sense. However, several academic groups and smaller biotechs have been examining anti-angiogenic agents, including bevacizumab used off-label, as well as investigational approaches targeting the ALK1/BMP9 signalling axis, which is mutated in the most common genetic forms of the disease. RougeTx's pericyte-restoration mechanism is differentiated from these approaches, though the company has not yet published clinical proof-of-concept data.
For investors, the key near-term milestone will be the filing of an IND or equivalent CTA in a European jurisdiction, followed by safety and pharmacokinetic data from first-in-human dosing. The rare-disease designation pathway in both the US and EU, which confers fee waivers, protocol assistance, and potential priority review, should support the regulatory timeline if RougeTx pursues it. The company's Netherlands base and its pan-European investor syndicate position it well within the EMA's orphan drug framework.