TVT-058 as an investigational therapeutic candidate for the treatment of classical homocystinuria.

TVT-058 (previously OT-58) is a novel investigational human enzyme replacement candidate being evaluated in Phase 1/2 development for the treatment of classical homocystinuria (HCU). Classical HCU is a rare metabolic disorder characterized by elevated levels of plasma homocysteine that can lead to vision, skeletal, circulatory and central nervous system issues. Learn more about classical HCU.


Current treatment options for people with classical HCU, including heavy dietary restrictions and supplemental use of vitamin B6 and betaine, are often ineffective in managing homocysteine levels and a significant unmet need remains.


TVT-058 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 TVT-058 program is to develop a well-tolerated, safe and effective treatment that sustainably replaces CBS to reduce levels of homocysteine.


TVT-058 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. TVT-058 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.