Evaluation of TYR Sphere

TYR sphere is a glycomacropeptide (GMP) based protein substitute for patients with tyrosinaemia. The Evaluation of TYR sphere study has been designed to generate data required by the United Kingdom's Advisory Committee on Borderline Substances (ACBS), the national regulator for Foods for Special Medical Purposes (FSMP). The ACBS specify that before a FSMP can be routinely prescribed by the NHS, its acceptability must first be evaluated by a clinical trial in patients for whom it is ultimately designed. The ACBS define acceptability as comprising patient evaluations of the product's palatability, data on their adherence to recommended intakes and their gastrointestinal tolerance of it. TYR sphere is designed for patients of three years of age and upwards. This has informed the trial's age-related inclusion criteria. Using a mobile phone application, or paper diary form, patients will record their intake of TYR sphere along with the recommended amount on each of the 28 study days. Gastrointestinal tolerance will be recorded each day during weeks one and four, while palatability of TYR sphere will be recorded at the end of the 28 days, or immediately on discontinuing TYR sphere if the patient stops the trial early. An evaluation of the patient's previous protein substitute and usual GI symptoms are recorded on day one, before the first intake of TYR sphere. Metabolic control, measured via dried blood spots taken at both visits, and weekly during the 28 days study period, is another primary outcome measure alongside acceptability. The trial's secondary endpoint is evaluations of growth. Height and weight will be recorded at the Baseline and End of Study visits. If it is deemed appropriate by the investigator, patients may continue to take the product at the end of the Evaluation Period as part of Care After Research. This continued supply would be given free of charge by the sponsor up until the product is available via a regular prescription, having completed the registration process with the ACBS.