Active not recruitingPHASE3INTERVENTIONAL

A Long-Term Safety Study of PTC923 in Participants With Phenylketonuria

This research study is designed to see how safe a new medicine called PTC923 is for people living with Phenylketonuria, or PKU, over a long period. PKU is a condition where the body can't properly process a substance called phenylalanine, found in protein. People with PKU usually need a very strict diet. The study also aims to understand if taking PTC923 allows participants to eat a wider variety of foods, specifically looking at how their intake of phenylalanine and protein might change from what they usually eat. It includes people who have been in previous studies and those who haven't, checking both those with controlled and uncontrolled phenylalanine levels.

At a glance

Status

Active not recruiting

Phase

PHASE3

Sponsor

PTC Therapeutics

Enrolment target

200

Start

14 Feb 2022

Estimated completion

30 Jun 2026

Phenylketonuria

What is this study about?

This study is investigating a new medication called PTC923 for people with a genetic condition called Phenylketonuria, or PKU. PKU means your body has trouble breaking down a substance called phenylalanine, which is found in protein-rich foods. If phenylalanine builds up, it can cause health problems, so people with PKU usually follow a very strict diet to control their levels.

The main goal of this study is to carefully watch the long-term safety of PTC923. Researchers want to make sure the medicine is well-tolerated and doesn't cause unexpected problems when taken over a longer time. They also want to see if the medicine helps people manage their PKU better, for example, by allowing them to eat a bit more protein or a wider range of foods than their usual strict diet permits. They'll measure how people's dietary phenylalanine and protein intake might change.

Participants in this study might be people who have already tried PTC923 in a previous study (these are called 'feeder participants'). It also includes people new to the medication, categorised based on their current phenylalanine levels in the blood – either controlled (low levels) or uncontrolled (higher levels). This helps researchers understand how PTC923 works in different situations.

Key takeaways

This study is testing a new medicine called PTC923 for Phenylketonuria (PKU).
Its main aim is to understand the long-term safety of PTC923.
Researchers will also see if the medicine helps people with PKU adjust their diet.
Both new participants and those from previous studies can join.
You'll have regular check-ups to monitor your health and diet.

Who may be eligible?

To join this study, you generally need to have a confirmed diagnosis of PKU and have had high phenylalanine levels in your blood in the past. If you are a woman who could become pregnant, you'll need to have a negative pregnancy test and agree to use effective birth control throughout the study and for 90 days after your last dose. Men who are sexually active with women who could become pregnant also need to use barrier birth control during this period and avoid donating sperm.

You should be willing to stick to your current diet unless the study doctors ask you to make changes. It's important that you can take medicines by mouth and are not pregnant or breastfeeding, or planning to become pregnant. You also can't have serious uncontrolled mental health conditions or certain kidney problems.

There are a few other reasons you might not be able to join, such as needing other medicines that could interfere with the study drug, like methotrexate, or if the researchers believe there's any other reason it wouldn't be safe or appropriate for you.

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.

Do I have a confirmed diagnosis of PKU?
Can I take medicines by mouth without problems?
If I am a woman, am I able to use effective birth control, and am I not pregnant or breastfeeding?
Do I have any serious kidney problems?
Do I need any other medicines that could interfere with the study drug?

Answer every question to see your result.

What does participation involve?

If you join the study, you'll be taking the study medicine, PTC923, as instructed by the study team. You'll have regular visits to the clinic so doctors can monitor your health, check your blood phenylalanine levels, and see how your diet might be changing. They will also look for any side effects from the medicine.

You will continue to follow your usual PKU diet unless the study doctor advises you to make adjustments. The study is designed to look at long-term safety, so it will involve regular check-ups over an extended period. The exact number of visits and the total duration will be explained in detail by the study team.

Potential risks and benefits

Participating in this study might offer you the potential benefit of trying a new medicine that could help manage your PKU. It could also provide valuable information that helps others with PKU in the future. However, as with any medicine, PTC923 might have side effects, some of which are not yet fully known. The study team will monitor you closely for any health changes. You have the right to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (46)

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

Children's Hospital Colorado
Verified postcode
Aurora, United States
UF College of Medicine, Department of Pediatrics Division of Genetics and Metabolism
Verified postcode
Gainesville, United States
Indiana University School of Medicine Department of Medical and Molecular Genetics
Verified postcode
Indianapolis, United States
Boston Children's Hospital
Verified postcode
Boston, United States
Icahn School of Medicine at Mount Sinai (ISMMS)
Verified postcode
New York, United States
UPMC Children's Hospital of Pittsburgh
Verified postcode
Pittsburgh, United States
University of Utah
Verified postcode
Salt Lake City, United States
The Queensland Children's Hospital
Verified postcode
South Brisbane, Australia
Westmead Hospital
Verified postcode
Westmead, Australia
PARC Clinical Research
Verified postcode
Adelaide, Australia
Royal Children's Hospital
Verified postcode
Parkville, Australia
Hospital de clinicas de Porto Alegre
Verified postcode
Porto Alegre, Brazil

Common questions

What is Phenylketonuria (PKU)?

PKU is a genetic condition where your body can't properly break down a substance called phenylalanine, which is found in protein. This means people with PKU need a special diet.

What is the new medicine, PTC923?

PTC923 is a new medicine being tested to see if it can help people with PKU manage their condition and potentially allow for a less restrictive diet.

Will I have to change my diet on this study?

You'll be asked to continue your current diet unless the study doctors specifically tell you to make changes. The study will monitor if your diet naturally changes over time.

What is the main goal of this study?

The main goal is to check how safe PTC923 is for people with PKU when taken over a long time, and to see if it affects their diet.

How long will I be in the study?

This is a long-term study, so your participation will involve regular check-ups over an extended period. The exact duration will be discussed with you.