Clinical trials

Phenylalanine (Phe) free protein substitutes are typically presented in ready to drink liquid or powder format and are made up with water to a set volume. Despite recent advancements related to the taste, scent and texture of commercially available protein substitutes, a proportion of PKU patients choose to consume tablet-based protein substitutes. Protein substitutes in tablet format may help overcome taste, scent and texture concerns associated with powdered and liquid preparations. Indeed, previous research has shown that protein substitute tablets are an effective strategy to manage PKU in children, teenagers and adults. Nonetheless, the daily burden and discipline required often impedes compliance, especially alongside the restrictive low-protein diet. Achieving compliance with multivitamin supplements when given alongside protein substitutes therefore becomes especially challenging. This is particularly true for adolescent, adult and maternal populations. PKU Microtablets have recently been developed. PKU Microtablets are a new phenylalanine-free tablet protein substitute combined with vitamins, minerals and trace elements. As patient acceptability is fundamental to the successful use of any protein substitute, investigation is needed to assess the compliance, tolerance and acceptability of PKU Microtablets as part of a low phenylalanine dietary regimen in PKU patients. This series of case-studies aims to evaluate the gastrointestinal tolerance, acceptability, compliance, and safety of this protein substitute in both adults and children from 4 years. These case studies will last 29 days in total, including a 1-day baseline period followed by a 28-day intervention period. The case studies will be conducted across multiple specialist metabolic centres in the UK.

This non-inferiority study aims to determine whether a hydrolysed rice protein formula is as effective as a cow's milk protein based extensively hydrolysed formula using a double-blind, randomised-controlled design over a 28-day intervention period followed by a 2-month follow-up period in infants 0-13 months of age presenting with symptoms/clinical history suggestive of cow's milk allergy. The primary outcome is growth, and secondary outcomes are gastrointestinal tolerance, and differences in intake, allergic symptoms, parental QOL, acceptability, dietary intake, and safety.

This study aims to determine whether a reformulated plant-protein dominant protein blend in four existing enteral tube feeds is as effective as animal-protein dominant formulations in patients who are tube fed at home. This is an exploratory randomised, controlled, trial with a 3-day baseline period. Adult home tube feeding patients will be randomised to receive either a plant-protein dominant formulation or a control product (an animal-protein dominant formulation) for a 3-month intervention period followed by a 6-month and 12-month follow-up. The outcomes include gastrointestinal tolerance, compliance, acceptability, anthropometry, nutrient intake, and physical function

Elemental 028 Extra is a nutritionally complete ACBS approved amino acid-based (elemental) feed designed to provide adequate daily amounts of both macronutrients and micronutrients when used as a sole source of nutrition and to support patients with severe impairment of the gastrointestinal tract who may require an elemental diet. An upgraded formulation of Elemental 028 Extra with an increased energy, protein content micronutrient profile has been developed to better meet the nutritional requirements of patients. This series of case-studies aims to evaluate the acceptability, compliance, and gastrointestinal tolerance of the upgraded formulation of Elemental 028 Extra, in 30 adult and paediatric patients (15 powder and 15 liquid), with conditions where there is a severe impairment of the gastrointestinal tract, such as inflammatory bowel disease, short bowel syndrome, intractable malabsorption, allergic disease, and neurodegenerative diseases, and an elemental feed is required. The case study will last 29 days in total, including a 1-day baseline period followed by a 28-day intervention period. The case studies will be conducted across multiple centres in the UK, to meet the UK ACBS and GMS requirements for acceptability studies.

Four new GMP-based protein substitutes have been developed to support the dietary management of PKU and TYR. These products are powdered protein substitutes, low in phenylalanine and low in phenylalanine and tyrosine respectively, with a mix of glycomacropeptide (GMP), essential and non-essential amino acids, carbohydrates, fibres, fats (including DHA) and micronutrients. The proteins in these new protein substitutes are based on GMP, a peptide isolated from milk during cheese manufacturing and the only known naturally derived protein source low in phenylalanine and tyrosine. The GMP is supplemented with other amino acids which are naturally low or not present in GMP, as well as carbohydrates, fats, fibre and micronutrients. Studies to date have illustrated that PKU patients who replace their regular phenylalanine-free amino acid-based formula with GMP-based foods may have better diet compliance and prefer the taste whilst maintaining metabolic control. This series of case-studies aims to evaluate the gastrointestinal tolerance, acceptability, compliance, and safety of these four GMP based protein substitutes in both adults and children over 3 years. These case studies will last 29 days in total, including a 1-day baseline period followed by a 28-day intervention period. The case studies will be conducted across multiple specialist metabolic centres in the UK. A series of case studies is undertaken due to the rarity of these conditions, the diversity of patient types and the difficulty in recruiting these patients to trials.