Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruitingRare disease

Long-Term Safety and Efficacy Study of Betibeglogene Autotemcel Gene Therapy for Patients with Transfusion-Dependent Beta-Thalassemia

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 focuses on the long-term follow-up of individuals with transfusion-dependent beta-thalassemia, a blood disorder that reduces the production of hemoglobin, the protein in red blood cells that carries oxygen. The study involves a treatment called LentiGlobin BB305 Drug Product, which is a type of gene therapy. This treatment uses a patient's own blood stem cells, which are modified outside the body to include a new gene that helps produce a functional protein. These modified cells are then returned to the patient through an infusion.

The purpose of the study is to monitor the long-term safety and effectiveness of this gene therapy in individuals who have already received the treatment in previous studies. Participants will be observed over an extended period to assess any potential long-term health effects, such as the development of new or worsening health conditions, including immune-related issues or blood disorders. The study will also evaluate how well the treatment works over time, including its impact on reducing the need for blood transfusions and improving hemoglobin levels.

Throughout the study, participants will undergo regular check-ups to track their health and any changes in their condition. This includes monitoring the expression of the therapeutic gene in their blood and assessing their overall quality of life. The study aims to provide valuable information on the long-term benefits and risks of using LentiGlobin BB305 Drug Product for treating transfusion-dependent beta-thalassemia.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Participation begins after providing written informed consent. This consent may be given by the patient or, if applicable, by the patient's parent or legal guardian.

    Eligibility requires previous treatment with the drug product for transfusion-dependent beta-thalassemia in a bluebird bio-sponsored clinical study.

  2. Step 2

    Treatment administration

    The treatment involves the use of LentiGlobin BB305 Drug Product, which is a dispersion for infusion.

    The drug is administered through intravenous use.

  3. Step 3

    Monitoring and follow-up

    The main objective is to monitor the long-term safety and efficacy of the gene therapy drug product.

    Monitoring includes checking for any new or worsening health conditions, such as malignancies, immune-related issues, or blood and neurological disorders.

  4. Step 4

    Evaluation of treatment effects

    The study evaluates the expression of a specific protein in the blood over time, particularly at 5, 10, and 15 years after the drug infusion.

    The study also assesses the patient's ability to maintain a certain level of hemoglobin without needing blood transfusions for at least 12 months.

  5. Step 5

    Assessment of transfusion needs

    The study examines the reduction in the need for blood transfusions over time, comparing it to the period before the study began.

    The time from the last blood transfusion to the last follow-up is also recorded.

  6. Step 6

    Iron burden and chelation therapy

    The study measures changes in iron levels in the body over time, using methods like MRI.

    The use of chelation therapy, which helps remove excess iron, is monitored, including the time from the last use to the last follow-up.

  7. Step 7

    Quality of life assessment

    The study evaluates the patient's quality of life over time using various validated tools.

    These assessments help understand the impact of the treatment on daily living and overall well-being.

Who can join the trial?

5 criteria

  • The patient or, if applicable, the patient's parent(s) or legal guardian(s) must provide written informed consent. This means they agree to participate in the study after being fully informed about it.
  • The patient must have been treated with the gene therapy drug product for transfusion-dependent beta-thalassemia in a previous clinical study sponsored by bluebird bio. Transfusion-dependent beta-thalassemia is a condition where the patient needs regular blood transfusions.
  • The study is open to both male and female patients.
  • The study includes patients who are considered part of a vulnerable population. This term refers to groups who may need special protection or care.
  • The study is open to patients in certain age ranges, specifically those who are children or adolescents.

Who cannot join the trial?

7 criteria

  • Patients who have not been treated with the gene therapy drug in previous studies cannot participate.
  • Patients who are not dependent on regular blood transfusions for their condition cannot participate.
  • Patients who have any other serious health conditions that might interfere with the study cannot participate.
  • Patients who are unable to follow the study procedures or attend follow-up visits cannot participate.
  • Patients who are pregnant or breastfeeding cannot participate.
  • Patients who have a history of allergic reactions to components of the gene therapy drug cannot participate.
  • Patients who are currently participating in another clinical trial cannot participate.
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

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

Ex Vivo Gene Therapy Using Autologous Hematopoietic Stem Cells Transduced With a Lentiviral Vector is a treatment designed for patients with transfusion-dependent β-thalassemia. In this therapy, a patient's own stem cells are collected and modified outside the body using a lentiviral vector. This vector is a tool that helps introduce new genetic material into the cells. The modified stem cells are then returned to the patient's body, where they can produce healthy blood cells. This therapy aims to reduce or eliminate the need for regular blood transfusions by addressing the underlying genetic cause of the disease.

What is already known about the treatment

Ex Vivo Gene Therapy Using Autologous Hematopoietic Stem Cells Transduced With a Lentiviral Vector – This treatment is administered through a process where a patient's own stem cells are collected, modified outside the body using a lentiviral vector, and then reintroduced into the patient. It is currently being studied in clinical trials for its long-term safety and effectiveness in treating transfusion-dependent beta-thalassemia. The therapy aims to correct the genetic defect causing the disease by inserting a functional gene into the patient's stem cells. It falls under the pharmacological classification of gene therapy.

Investigated diseases

Beta-thalassemia – Beta-thalassemia is a blood disorder that reduces the production of hemoglobin, the protein in red blood cells that carries oxygen throughout the body. This condition results in anemia, which can cause fatigue, weakness, and pale skin. In severe cases, individuals may require regular blood transfusions to manage symptoms and maintain adequate hemoglobin levels. Over time, the body may accumulate excess iron due to frequent transfusions, potentially leading to complications in organs such as the heart and liver. The severity of symptoms can vary widely, with some individuals experiencing mild anemia and others facing more serious health challenges. The condition is typically inherited and is more common in certain populations, particularly those of Mediterranean, Middle Eastern, and Asian descent.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-513905-29-00Protocol codeLTF-303Estimated enrolment66 patientsSponsorGenetix Biotherapeutics Inc.

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

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.

ClinicalTrials.eu

Every clinical trial in Europe, in plain language.

Explore the full ecosystem of clinical research in Europe.

Search trials

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).