Not recruitingRare disease

Long-Term Study on the Safety of Avalotcagene Ontaparvovec for Adults with Late-Onset Ornithine Transcarbamylase Deficiency

Verified siteInvestigational

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a condition known as Ornithine Transcarbamylase (OTC) deficiency, which is a rare genetic disorder that affects the body's ability to eliminate ammonia, a waste product. The study is investigating a treatment called Avalotcagene ontaparvovec, also known by its code name DTX301. This treatment involves a type of gene therapy using a virus to deliver a healthy copy of the OTC gene to the patient's cells. The virus used in this therapy is a recombinant adeno-associated viral vector, which is designed to be safe and effective in transferring the gene.

The purpose of the study is to evaluate the long-term safety of this gene therapy in adults who have late-onset OTC deficiency. Participants in the study will receive a single dose of the treatment through an intravenous infusion, which means it will be administered directly into the bloodstream. The study will follow participants over an extended period to monitor their health and any changes in their condition. This will help researchers understand how the treatment affects the body over time and whether it can safely reduce the symptoms of OTC deficiency.

Throughout the study, researchers will collect information on any side effects experienced by participants and how these relate to the treatment. They will also measure changes in the levels of ammonia in the blood and the body's ability to produce urea, a process known as ureagenesis. These measurements will help determine the effectiveness of the treatment in managing OTC deficiency. The study aims to provide valuable insights into the potential of gene therapy as a long-term solution for individuals with this condition.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

Step 1
Joining the study
To participate in this study, you must have completed the Week 52 visit in a previous study called Study 301OTC01. The first day of this new study, Study 301OTC02, may coincide with your Week 52 visit from the previous study.
You will need to provide written consent, confirming your willingness to participate and comply with the study requirements.
Step 2
Receiving the treatment
You will receive a single dose of a treatment called avalotcagene ontaparvovec. This is a solution that will be administered through an intravenous infusion, meaning it will be given directly into your vein.
The purpose of this treatment is to evaluate its long-term safety and effectiveness in managing your condition, which is known as ornithine transcarbamylase deficiency.
Step 3
Monitoring and follow-up
After receiving the treatment, you will be monitored for any side effects or adverse events. These will be assessed based on their severity and whether they are related to the study product.
Your progress will be tracked over a period of up to 416 weeks. This includes measuring changes in your plasma ammonia levels and the rate at which your body produces urea, a waste product formed in the liver.
Step 4
Study visits and procedures
You will be required to attend scheduled visits to the study site. During these visits, various procedures and assessments will be conducted to monitor your health and the effects of the treatment.
It is important to adhere to the schedule and follow all study-related instructions to ensure accurate and reliable results.

Who can join the trial?

3 criteria

Must have completed the Week 52 visit in Study 301OTC01. The Day 0 visit of Study 301OTC02 may happen at the same time as the Week 52 visit of Study 301OTC01.
Must be willing and able to provide written informed consent. This means you agree to participate in the study and understand what it involves.
Must be willing, able, and committed to follow the schedule for study site visits, study procedures, and requirements.

Who cannot join the trial?

10 criteria

Patients with a history of severe allergic reactions to any component of the study medication cannot participate.
Individuals who have received another investigational drug within the last 30 days are not eligible.
Patients with uncontrolled medical conditions that could interfere with the study are excluded.
Pregnant or breastfeeding women are not allowed to participate.
Individuals with a history of drug or alcohol abuse within the past year are not eligible.
Patients with a history of liver disease, other than **Ornithine transcarbamylase deficiency**, are excluded.
Individuals who have had a major surgery within the last 3 months cannot participate.
Patients with a history of cancer, except for certain types of skin cancer, are not eligible.
Individuals with a known infection with **HIV**, **Hepatitis B**, or **Hepatitis C** are excluded.
Patients who are unable to comply with the study procedures are not eligible.

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Verified
Universidade De Santiago De Compostela
Santiago De Compostela, Spain

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not recruiting

Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

DTX301 is a gene therapy treatment being studied for its potential to help people with a condition called late-onset ornithine transcarbamylase (OTC) deficiency. This condition affects how the body processes certain proteins, leading to a buildup of ammonia in the blood, which can be harmful. DTX301 uses a virus called adeno-associated virus serotype 8 (AAV8) to deliver a healthy copy of the OTC gene into the patient's liver cells. The goal is to help the liver produce the enzyme needed to process proteins properly, reducing ammonia levels and improving the patient's health. This study is focused on understanding the long-term safety of this treatment after a single dose is given through an IV.

Avalotcagene Ontaparvovec

What is already known about the treatment

DTX301 – DTX301 is administered as a single intravenous (IV) dose, meaning it is delivered directly into the bloodstream through a vein. This medication is currently being studied in clinical trials to assess its long-term safety and effectiveness for treating adults with late-onset ornithine transcarbamylase (OTC) deficiency, a rare genetic disorder. The main therapeutic goal of DTX301 is to address the deficiency of the OTC enzyme, which is crucial for removing ammonia from the body. At the molecular level, DTX301 works by using a virus called adeno-associated virus (AAV) serotype 8 to deliver a healthy copy of the human OTC gene to the patient's liver cells, helping them produce the missing enzyme. This medication falls under the pharmacological classification of gene therapy, which involves modifying or manipulating genes to treat or prevent disease.

Investigated diseases

Ornithine transcarbamylase deficiency – Ornithine transcarbamylase deficiency is a genetic disorder that affects the urea cycle, a process in the liver that removes ammonia from the blood. This condition is caused by mutations in the OTC gene, leading to a deficiency of the enzyme ornithine transcarbamylase. As a result, ammonia accumulates in the blood, which can be toxic to the brain and other organs. Symptoms can vary but often include episodes of vomiting, lethargy, and confusion, especially after consuming protein-rich foods. Over time, individuals may experience developmental delays and neurological issues. The severity of the condition can differ, with some individuals experiencing mild symptoms and others having more severe manifestations.