Clinical Research Directory

Proof of Concept Creatine Supplementation for Homocystinuria Study

Homocystinuria is a rare and inherited metabolic disorder, people with this condition don't have an enzyme needed to break down an amino acid called homocysteine. When the body can't break down the homocysteine made from another amino acid methionine, it becomes toxic to the heart, brain, and bones. We are constantly eating methionine, a building block of protein, so a common treatment is eating a low-protein diet with medical foods and vitamin pills. This can be hard to follow due to bad tastes and missing out on foods a person enjoys, especially in children. The goal of this study is to provide participants with a supplement containing creatine, another amino acid related to methionine and homocysteine, and learn if it lowers homocysteine production in healthy adult men. We would ultimately like to see if creatine supplements are a potential alternate treatment of Homocystinuria in this proof of concept study, before studying individuals with the condition. Researchers in this study want to know: * How does the bodies digestion of isotope methionine change in breath and urine when creatine is taken in healthy young adult men? * How do levels of homocysteine, methionine and related metabolites change in the blood when creatine is taken by healthy young adult men? Participants will: * Complete two (2), 8-hour study days on-site. * Eat a lower protein diet for one (1) week before the first study day, and eat a lower protein diet with creatine supplements for one (1) week before the second study day. * During both study days eat special hourly meals of controlled amino acids and nutrients, along with a methionine isotope. (An isotope is a stable labelled amino acid that is colourless, odorless, tasteless, and safe for consumption. In the lab we can detect this isotope in breath and urine samples collected during the study day). * Provide samples of breath, urine and blood. (Researchers will also take body measurements (height weight), and use non-invasive tests to measure body composition and energy needs).

A Phase 3 Long-term Extension Study to Assess the Long-term Safety and Efficacy of Pegtibatinase Treatment in Participants ≥5 to ≤65 Years of Age With Classical Homocystinuria (HCU) (ENSEMBLE)

The goal of this long-term extension (LTE) study is to evaluate the safety and efficacy of pegtibatinase in patients with classical homocystinuria (HCU). Patients who are active in the Phase 1/2 COMPOSE study or those who complete the 24 weeks of treatment in the Phase 3 HARMONY are eligible to participate. Participants will be in this clinical study for up to about 13 months including: * a treatment period of up to 104 weeks * a 4-week safety follow-up period

Health Related Quality of Life (HrQoL) in Classical Homocystinuria (CBS Deficiency)

Patients, parents of young / handicapped patients, and experts will be interviewed to collect contents relevant for HrQoL in CBS deficiency. Based on these data, a questionnaire will be developed and tested for comprehensibility in patients and parents of young / handicapped patients. A final questionnaire version will be tested for psychometric criteria including validity and reliability.

A Study to Investigate Efficacy and Safety of Pegtibatinase Compared With Placebo in Participants ≥12 to ≤65 Years of Age With Classical Homocystinuria (HCU) Due to Cystathionine Beta Synthase Deficiency Receiving Standard of Care Treatment

The purpose of this study is to measure efficacy and safety of pegtibatinase treatment compared with placebo in participants with classical HCU receiving standard of care who have not achieved tHcy target levels. Study details include: * Total Study duration: up to 38 weeks * Screening: * Initial Screening duration: up to 4 weeks * Pre-treatment Diet Standardization Period duration: up to 6 weeks * Blinded Treatment Duration: 24 weeks * 2-week blinded dose titration period * 22-week blinded assessment period * Safety Follow-Up: 4 weeks after last dose (as applicable for those not enrolling in the long term extension study, ENSEMBLE)

Early Check: Expanded Screening in Newborns

Early Check provides voluntary screening of newborns for a selected panel of conditions. The study has three main objectives: 1) develop and implement an approach to identify affected infants, 2) address the impact on infants and families who screen positive, and 3) evaluate the Early Check program. The Early Check screening will lead to earlier identification of newborns with rare health conditions in addition to providing important data on the implementation of this model program. Early diagnosis may result in health and development benefits for the newborns. Infants who have newborn screening in North Carolina will be eligible to participate, equating to over 120,000 eligible infants a year. Over 95% of participants are expected to screen negative. Newborns who screen positive and their parents are invited to additional research activities and services. Parents can enroll eligible newborns on the Early Check electronic Research Portal. Screening tests are conducted on residual blood from existing newborn screening dried blood spots. Confirmatory testing is provided free-of-charge for infants who screen positive, and carrier testing is provided to mothers of infants with fragile X. Affected newborns have a physical and developmental evaluation. Their parents have genetic counseling and are invited to participate in surveys and interviews. Ongoing evaluation of the program includes additional parent interviews.

Pegtibatinase As an Enzyme Therapy for Patients with Homocystinuria Caused by Cystathionine Beta-Synthase Deficiency (COMPOSE)

Homocystinuria caused by Cystathionine Beta-Synthase (CBS) Deficiency is a rare autosomal-recessive metabolic condition characterized by an excess of homocysteine (Hcy) in the plasma, tissues and urine. It is due to reduced or absent activity of the CBS enzyme, and is also known as classical homocystinuria. The symptoms associated with homocystinuria are variable in severity and time of onset across patients. Some affected individuals may have mild signs of the disorder; others may have multi-systemic involvement including potentially life-threatening complications. Homocystinuria can affect many different organ systems of the body; the four most commonly involved are the eyes, central nervous system, skeleton, and the vascular system. The current approaches to treatment of homocystinuria patients include a highly restrictive diet and use of dietary supplements. Lifetime compliance with this diet is poor. Pegtibatinase (TVT-058) represents a novel therapeutic approach that incorporates the use of a modified version of the native, human CBS (hCBS) enzyme. The goal of treatment is to introduce the CBS enzyme into circulation, resulting in reduced Hcy levels, increased cystathionine (Cth) and cysteine (Cys) levels.