Evaluating the Adherence, Tolerance, Acceptability and Safety of New GMP-based Powdered Protein Substitutes in Phenylketonuria and Tyrosinemia: a Case Study Series

What this Trial Is About

Researchers are studying new powdered protein substitutes based on glycomacropeptide (GMP) to help manage the diets of people with Phenylketonuria (PKU) and Tyrosinemia (TYR). These conditions require controlling intake of phenylalanine and tyrosine, and GMP is a naturally derived protein low in these amino acids. The research focuses on evaluating how well adults and children over 3 years tolerate, accept, and comply with these new GMP-based substitutes, while also monitoring their safety. The study involves using four different GMP-based protein substitutes that include a mix of essential and non-essential amino acids, carbohydrates, fibers, fats including DHA, and micronutrients. Participants will replace their regular protein substitute with one of these GMP products for 28 days after a 1-day baseline period. This case series is conducted across multiple UK specialist metabolic centers, reflecting the rarity and diversity of these conditions. Participants will be observed over 29 days, with assessments at baseline and after the intervention period. Researchers will measure gastrointestinal tolerance, acceptability, compliance, blood levels of phenylalanine, tyrosine, and other amino acids, as well as physical measurements and patient history. Safety and any adverse events will be monitored throughout. The goal is to understand how well patients tolerate these new products and maintain their metabolic control during the study.

GMP Powdered Substitutes in PKU and TYR