Active not recruitingOBSERVATIONAL

Long Term Follow Up to Evaluate DTX301 in Adults With Late-Onset OTC Deficiency

This study is a follow-up to an earlier trial, looking at the long-term safety of a treatment called DTX301 for adults with a genetic condition known as late-onset Ornithine Transcarbamylase (OTC) Deficiency. OTC deficiency means the body has trouble breaking down certain proteins, which can lead to a build-up of harmful substances. DTX301 is a type of gene therapy designed to help the body make a missing enzyme. Participants in this follow-up study will be those who have already completed the first study (called 301OTC01). The main aim is to understand if the treatment continues to be safe over a long period. This study does not involve new treatment, but rather observing the effects of the treatment already received.

At a glance

Status

Active not recruiting

Sponsor

Ultragenyx Pharmaceutical Inc

Enrolment target

Start

30 Aug 2018

Estimated completion

01 Dec 2029

Ornithine Transcarbamylase (OTC) Deficiency

What is this study about?

This study is called a 'long-term follow-up' because it aims to see how people are doing over a longer period after receiving a particular treatment. The treatment, called DTX301, is designed for adults who have a rare genetic condition called late-onset Ornithine Transcarbamylase (OTC) Deficiency.

OTC deficiency happens when the body is missing an important enzyme. Without this enzyme, the body struggles to process protein properly, which can lead to harmful substances building up in the blood. DTX301 is a type of gene therapy where a healthy copy of the gene for this missing enzyme is delivered to the body. This study wants to make sure that the treatment remains safe and continues to work well over time, after people have already been given a single dose.

This specific study doesn't involve getting a new treatment. Instead, it's for people who have already taken part in an earlier study of DTX301. Researchers will continue to monitor these individuals to gather important information about the long-term effects of the gene therapy. This kind of follow-up is very important for understanding how new treatments behave over many years.

Key takeaways

This is a follow-up study for a gene therapy called DTX301.
It's for adults with late-onset OTC Deficiency who have already received DTX301.
The main goal is to check the long-term safety of the treatment.
You won't receive new medication; it's about monitoring your health.
Your participation helps gather vital information for future treatments.

Who may be eligible?

To join this study, you must be an adult aged 18 or older. Importantly, you can only take part if you have already completed all the visits for a previous study related to this treatment, called Study 301OTC01. This means you would have already received the DTX301 treatment in the earlier study.

You also need to be willing to give your written permission to join the study and be able to keep to the schedule of visits and follow all the study instructions. The researchers want to make sure you can safely take part and that they can get accurate information from you.

You cannot join if you are already taking part in another medical study that involves receiving a treatment, as this might make it hard to tell if any effects are from DTX301 or the other treatment. Also, if a doctor feels that joining this study might put your health at risk, 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 18 years old or older?
Did you complete all visits for the previous study called 301OTC01?
Are you able and willing to attend scheduled appointments and follow study instructions?
Are you currently NOT participating in another medical study involving a treatment?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this follow-up study, you won't be receiving any new medication. Instead, your participation will involve attending scheduled visits at the study centre. During these visits, the medical team will carry out various assessments to check your health and how you are doing after receiving the DTX301 treatment in the previous study. This might include blood tests, physical examinations, and asking you questions about your well-being.

The researchers will explain the exact schedule of visits and what each visit will involve. They will also tell you the total duration of your involvement in this long-term follow-up. It's important that you commit to attending all these scheduled appointments to help the researchers gather complete information. The study will continue to monitor you for a longer period to understand the lasting effects of the treatment.

Potential risks and benefits

Because this study is a follow-up and you won't be receiving new treatment, the direct risks are generally low, focusing more on the inconvenience of visits and minor discomfort from tests like blood draws. The potential benefit is that your participation helps researchers understand the long-term safety and effects of DTX301, which could help future patients with OTC deficiency. You have the right to withdraw from the study at any time, for any reason, without affecting your medical care.

Locations (9)

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

The Children's Hospital Colorado
Verified postcode
Aurora, United States
Boston Children's Hospital
Verified postcode
Boston, United States
Icahn School of Medicine
Verified postcode
New York, United States
University Hospital Cleveland Medical Center/Case Western Reserve University
Verified postcode
Cleveland, United States
M.A.G.I.C. Clinic
Verified postcode
Calgary, Canada
Hopital Femme Mere Enfant
Verified postcode
Bron, France
Hospital Clinico Universitario de Santiago
Verified postcode
Santiago de Compostela, Spain
Hospital Universitario de Cruces. Servicio de Pediatria
Verified postcode
Barakaldo, Spain
Queen Elizabeth Hospital, Department of Endocrinology
Verified postcode
Birmingham, United Kingdom

Common questions

What is OTC deficiency?

It's a rare genetic condition where your body can't properly process certain proteins, which can lead to harmful substances building up.

Will I receive any new treatment in this study?

No, this study is a follow-up. You would have already received the treatment (DTX301) in an earlier study.

Why is a long-term follow-up important?

It helps doctors understand how safe and effective a new treatment is over many years, which is crucial for new medicines.

What kind of tests will I have?

You'll likely have regular health checks, physical exams, and blood tests to monitor your health.

Can I leave the study if I change my mind?

Yes, you can choose to leave the study at any time, and it won't affect your medical care.