Patient Studies and Clinical Trials

Clinical trials and patient studies are critical to enabling the development of new therapies to treat diseases like homocystinuria. Your participation in a study can contribute to ground-breaking medical advancements that will ultimately improve health outcomes for you and the entire homocystinuria community.

Community members on the Homocystinuria Patient Register are contacted directly about upcoming clinical trials and studies relevant to them. If you would like to be notified of upcoming studies and clinical trials, please join the Homocystinuria Patient Register.

Current Studies


AGLE-177 is a novel engineered human enzyme designed to degrade both homocysteine and homocystine (two homocysteine molecules bound together) to lower abnormally high levels of homocysteine in the blood. Aeglea have initiated a first-in-human Phase 1/2 clinical trial to investigate the effectiveness of AGLE-177 in lowering levels of total homocysteine (homocysteine plus homocystine) in people with Homocystinuria.

The multicenter, open label, dose escalation Phase 1/2 trial is anticipated to enroll 16-20 patients diagnosed with Homocystinuria aged 12 years or older at sites located in the United Kingdom and Australia. The primary endpoint is the safety and tolerability of AGLE-177 (formerly known as ACN00177). Secondary endpoints include pharmacokinetic assessments as well as reduction in plasma total homocysteine levels. Patients will be dosed weekly for four weeks.

AGLE-177 has been granted Rare Paediatric Disease and Orphan Drug Designations by the U.S. FDA and received Orphan Drug Designation from the European Medicines Agency

More information about the trial can be found on EU Clinical Trials Register.


Pegtibatinase (TVT-058) is a novel investigational human enzyme replacement candidate being evaluated in Phase 1/2 development for the treatment of classical homocystinuria (HCU).

Pegtibatinase is a PEGylated, recombinant enzyme replacement candidate designed to address the underlying cause of classical HCU — a deficiency in the naturally occurring enzyme cystathionine beta synthase (CBS). The goal of the pegtibatinase program is to develop a well-tolerated, safe and effective treatment that sustainably replaces CBS to reduce levels of homocysteine.

Pegtibatinase is currently advancing in a Phase 1/2 dose escalation study to assess its safety, tolerability, pharmacokinetics, pharmacodynamics and clinical effects in patients with classical HCU.

Pegtibatinase has been granted Rare Pediatric Disease and Fast Track designations by the US Food and Drug Administration (FDA), as well as orphan drug designation in the US and Europe.

More information about the trial can be found on US Clinical Trials Register


The Natural History Study is an observational study designed to characterize the clinical course of homocystinuria in paediatric and adult patients aged 5 to 65 years under current clinical management practices.

More information about the trial can be found on US Clinical Trials Register




Patient Studies and Clinical Trials