RecruitingNAINTERVENTIONAL

GMP Powdered Substitutes in PKU and TYR

This study is testing four new powdered protein products designed for people living with rare conditions called Phenylketonuria (PKU) and Tyrosinemia (TYR). These conditions mean your body can't properly process certain amino acids found in protein, so you need special diets and protein substitutes. The new products use Glycomacropeptide (GMP), a natural substance from milk, combined with other important nutrients. Researchers want to see if these new GMP-based drinks are well-tolerated, taste good, and help people stick to their diet. Previous findings suggest GMP products might be preferred and help patients stay on track with their treatment more easily. This study will involve adults and children over 3 years old, lasting about 29 days, and will take place in several UK specialist centres.

At a glance

Status

Recruiting

Phase

Sponsor

Nutricia UK Ltd

Enrolment target

Start

20 May 2025

Estimated completion

31 Dec 2026

Phenylketonuria Tyrosinemia

What is this study about?

You're probably here because you or someone you care for has Phenylketonuria (PKU) or Tyrosinemia (TYR). These are rare conditions where your body can't break down parts of protein properly. This means you need a very specific diet, including special protein substitutes, to stay healthy. Traditional protein substitutes can sometimes be challenging to take, perhaps due to taste or texture, and sticking to the diet is super important.

This study is looking at four new powdered protein drinks that could offer a different option. These drinks are special because they're based on something called Glycomacropeptide (GMP). GMP is a natural part of milk that's left over when cheese is made, and it's unique because it's naturally very low in the specific amino acids (like phenylalanine for PKU, or phenylalanine and tyrosine for TYR) that people with these conditions need to limit. These new products also have other important ingredients like vitamins, minerals, healthy fats, and fibres to make them complete.

We've learned from earlier studies that people with PKU who've tried GMP-based foods often find them more pleasant to take and easier to stick with, all while keeping their conditions well-managed. This new study aims to see how well these four specific GMP drinks are tolerated by the tummy, if people find them acceptable and easy to use, whether they help people stick to their diet, and if they are safe for both adults and children over 3 years old. Because these conditions are rare, a series of smaller case studies will be conducted across different specialist centres in the UK.

Key takeaways

New protein drinks based on natural milk ingredient (GMP) are being tested.
Aims to find tastier, easier-to-take options for people with PKU and TYR.
Study lasts 29 days for children and adults over 3 years old.
Focuses on how well the drinks are tolerated, their taste, and safety.
You'll switch from your current protein substitute to the study product.

Who may be eligible?

To join this study, you would need to be over 3 years old and have a diagnosis of either Phenylketonuria (PKU) or Tyrosinemia (TYR). It's important that you've been regularly taking another protein substitute (providing at least 15 grams of protein equivalent) for at least a month before the study starts. You also need to have a specific diet plan from your doctor that tells you how much phenylalanine (or phenylalanine and tyrosine for TYR) you can have each day.

We would also need to make sure you're able to take at least one serving of the new GMP product each day during the study. Before taking part, you, or your parent/guardian if you're a child, will need to give your informed consent, which means agreeing to participate after understanding all the details.

You wouldn't be able to join if you are pregnant or breastfeeding, or if you need to be fed through a tube (parenteral nutrition). Also, if you have severe liver or kidney problems, or have participated in another study in the last month, you wouldn't be eligible. Lastly, if you have an allergy to any of the ingredients in the study product, or if the research team feels it might be difficult for you to follow the study plan, you wouldn't be able to participate.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you over 3 years old?
Do you have a diagnosis of PKU or TYR?
Have you been regularly taking a protein substitute for at least one month?
Do you have a daily allowance for phenylalanine (or phenylalanine and tyrosine) from your doctor?
Are you able to take at least one serving of a powdered drink each day?
Are you not pregnant or breastfeeding, and don't have severe liver or kidney problems?

Answer every question to see your result.

What does participation involve?

If you decide to take part, the study will last for a total of 29 days. This includes a 1-day 'baseline' period at the start, where your usual routine is noted. After that, you'll enter a 28-day period where you will introduce one of the new GMP-based protein drinks into your daily diet, as advised by the study team. You'll switch from your current protein substitute to one of the new study drinks. Doctors and nurses will check in with you to see how you're feeling, how well you tolerate the drink, and if you like the taste. This will help them understand if the new products are helpful and easy to use. No specific visits are detailed beyond this, but it implies regular checks and discussions about your experience with the new product will happen throughout the 28 days.

Potential risks and benefits

Participating in this study might offer you the chance to try a new type of protein substitute that some patients have found tastier and easier to stick with, potentially leading to better dietary control for your condition. However, there's always a possibility that the new product might not suit you, or you might experience some digestive upset or not like the taste. The study team will carefully monitor your health throughout. Remember, taking part is completely voluntary, and you have the right to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Birmingham Women and Children's Hospital
Verified postcode
Birmingham, United Kingdom· Recruiting

Common questions

What are PKU and TYR?

PKU (Phenylketonuria) and TYR (Tyrosinemia) are rare genetic conditions where your body can't properly process certain parts of protein, requiring a special lifelong diet including special protein drinks.

What is GMP?

GMP stands for Glycomacropeptide. It's a natural protein from milk, created during cheese making, and is special because it's naturally very low in phenylalanine and tyrosine, which are important for people with PKU and TYR to limit.

How long does the study last?

The study will last for a total of 29 days: one day for initial checks, followed by 28 days of using the new protein substitute.

Will I have to stop my current treatment?

Yes, during the 28-day intervention period, you will be replacing your usual protein substitute with one of the new GMP-based study products.

Who can take part?

Children and adults over 3 years old with PKU or TYR, who regularly take a protein substitute, might be eligible. There are also some conditions that would prevent participation, like pregnancy or severe liver/kidney issues.

How to find out more

Ellen Taylor

ellen.taylor@nutricia.com 07900724091 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.