Hereditary Hemorrhagic Telangiectasia (HHT) Clinical Trials

Hereditary Hemorrhagic Telangiectasia results from mutations in genes regulating blood vessel integrity, most commonly endoglin (ENG gene, HHT1) or activin receptor-like kinase 1 (ALK1, HHT2 gene), and less commonly other genes. These mutations impair transforming growth factor-beta (TGF-β) signaling, crucial for proper blood vessel development and maintenance. The hallmark features include telangiectasias (small dilated blood vessels in skin and mucous membranes) and arteriovenous malformations (direct connections between arteries and veins lacking intervening capillaries).

The most common symptoms of Hereditary Hemorrhagic Telangiectasia include Frequent and recurrent nosebleeds (epistaxis), Mucocutaneous telangiectasias (small red spots on lips, fingers, mucous membranes), Gastrointestinal bleeding with anemia and bloody stools, Shortness of breath from pulmonary arteriovenous malformations, Headaches or neurologic symptoms from cerebral malformations, among others. Approximately 1 in 5,000 to 10,000 people. Symptoms can range from mild to severe and may vary between individuals.

Trial Friend lists all active clinical trials for Hereditary Hemorrhagic Telangiectasia from ClinicalTrials.gov, with eligibility criteria translated into plain English. Patients can filter by trial phase and recruitment status, search by location, and use the Match Me tool to score trials against their profile. Research in Hereditary Hemorrhagic Telangiectasia is focused on reducing bleeding through innovative approaches targeting blood vessel formation. Antiangiogenic agents like bevacizumab and alternatives are being studied in various forms, including as nasal spray for nosebleed control, alongside other agents like thalidomide and lenalidomide.

As of September 2026, Trial Friend's curated drug index does not include an FDA-approved treatment specific to Hereditary Hemorrhagic Telangiectasia. The Treatments section of this page checks FDA drug labels live and lists any approved drug whose label names the condition, and the trials listed below cover the investigational options.

Hereditary Hemorrhagic Telangiectasia is caused by variants in the ENG, ACVRL1, SMAD4 and GDF2 genes. ENG (type 1) and ACVRL1 (type 2) cause most cases; SMAD4 also causes juvenile polyposis.

It is autosomal dominant, so each child of an affected parent has a 1 in 2 chance of inheriting it. Approximately 1 in 5,000 to 10,000 people. Genetic testing confirms the diagnosis.

Yes. Genetic testing for Hereditary Hemorrhagic Telangiectasia looks at the ENG, ACVRL1, SMAD4 and GDF2 genes. ENG (type 1) and ACVRL1 (type 2) cause most cases; SMAD4 also causes juvenile polyposis.

It is autosomal dominant, so each child of an affected parent has a 1 in 2 chance of inheriting it.

A confirmed variant establishes the diagnosis and is often required to enroll in gene-specific trials. The labs currently offering the test are listed in the Genetic Testing section of this page, pulled live from the NIH Genetic Testing Registry. A genetic counselor can help interpret the result and decide which relatives should be tested.

Eligibility for Hereditary Hemorrhagic Telangiectasia clinical trials depends on factors like age, diagnosis, treatment history, and overall health. Each trial sets its own inclusion and exclusion criteria. Trial Friend translates these requirements from medical language into plain English so patients can review them more easily. The Match Me tool can score your profile against active trials to help identify studies that may be a fit.

Participating in a Hereditary Hemorrhagic Telangiectasia clinical trial typically involves scheduled visits, medical tests, and close monitoring by a research team. Depending on the study phase, you may receive an investigational treatment, a placebo, or the current standard of care. Trials may last from a few weeks to several years. Study participation is voluntary, and you can withdraw at any time.