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Long-Term Safety Study of HepaStem for Patients with Urea Cycle Disorders, Crigler-Najjar Syndrome, and Fibroinflammatory Liver Diseases

Verified siteInvestigationalNo placebo
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What is this trial about?

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

This clinical trial is focused on understanding the long-term safety of a treatment called HepaStem. HepaStem is a type of cell therapy, which means it uses specially prepared cells to help treat certain diseases. The diseases being studied in this trial include urea cycle disorders, Crigler-Najjar syndrome, and various fibroinflammatory liver diseases. These conditions can affect how the liver functions and processes substances in the body.

The purpose of this study is to monitor patients who have previously received at least one infusion of HepaStem in earlier clinical trials. The study aims to ensure that the treatment remains safe over a long period. Patients who have participated in these earlier studies will continue to be observed to check for any potential side effects or health changes. This includes looking out for serious events such as organ transplants, the development of tumors, or any diseases that might arise from infections or reactivation of dormant viruses.

Participants in this study will not receive any new treatments but will be regularly monitored to gather information about their health following their initial HepaStem treatment. This monitoring will help researchers understand the long-term effects of the therapy and ensure that it is safe for continued use in treating these liver-related conditions.

The research process

The trial runs in 3 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, it is confirmed that you have previously received at least one infusion of HepaStem during an earlier clinical study. This is a requirement to participate in the current study.

    You will be asked to provide written informed consent. If you are a minor, your parent or legal representative will provide consent on your behalf. If you become an adult during the study, you will need to provide your own consent.

  2. Step 2

    Study participation

    The main objective of this study is to assess the long-term safety of HepaStem therapy. This involves monitoring for any adverse events or health issues that may arise after receiving the treatment.

    The study will document any significant health events, such as organ transplantation, development of tumors, or any disease linked to infections. Any health issue that may be related to HepaStem will be carefully recorded.

  3. Step 3

    Monitoring and follow-up

    Throughout the study, regular follow-ups will be conducted to monitor your health status. This will help in identifying any long-term effects of the HepaStem treatment.

    The study is expected to continue until July 2028, ensuring comprehensive long-term safety data is collected.

Who can join the trial?

7 criteria

  • Patients who have received at least one infusion of HepaStem during a previous clinical study conducted by Promethera Therapeutics.
  • Patients who can understand and give written informed consent. This means they agree to participate in the study after being informed about it.
  • For children, consent must be given by parents or a legal representative. If the child can understand the study, they should also agree and sign a form.
  • If a patient is a minor (underage) when joining the study and becomes an adult during the study, they must provide their own consent as an adult.
  • For adults who cannot give consent due to a condition affecting their ability to understand, a legal representative must provide consent. If the patient's condition improves, they must give their own consent as soon as they are able.
  • The study includes both male and female patients.
  • The study includes patients from vulnerable populations, which means groups that might need special protection or care.

Who cannot join the trial?

3 criteria

  • Patients who have not received at least one infusion of the Investigational Medicinal Product (IMP) called HepaStem HALPC in a previous clinical study cannot participate.
  • Patients who did not participate in a previous interventional clinical study conducted by Promethera Biosciences or Promethera Therapeutics are excluded.
  • Patients who do not have conditions such as **urea cycle disorders (UCD)**, **Crigler-Najjar (CN)**, or **Fibroinflammatory liver diseases** are not eligible.
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Investigated drugs

HepaStem is a therapy that involves using special cells derived from the liver. These cells are designed to help repair and regenerate damaged liver tissue. In this clinical trial, the focus is on understanding how safe HepaStem is for patients over a long period after they have received it in a previous study. The therapy aims to support liver function and improve the health of patients with liver conditions by providing the liver with the necessary cells to aid in its healing process.

What is already known about the treatment

HepaStem – HepaStem is administered through an infusion, which means it is delivered directly into the bloodstream. It is currently being studied for its long-term safety in patients who have previously received it in clinical trials. The main therapeutic indications for HepaStem include urea cycle disorders, Crigler-Najjar syndrome, and fibroinflammatory liver diseases. At the molecular level, HepaStem works by providing healthy liver cells that can help improve liver function. It is classified as a cell therapy product, which involves using living cells to treat or manage diseases.

Investigated diseases

  • Urea Cycle Disorders

    Urea Cycle Disorders are a group of genetic conditions that affect the body's ability to remove waste nitrogen. This occurs due to a deficiency in one of the enzymes in the urea cycle, leading to an accumulation of ammonia in the blood. Ammonia is toxic, especially to the brain, and can cause neurological problems. Symptoms can include vomiting, lethargy, and in severe cases, coma. The progression of the disease can vary, with some individuals experiencing symptoms shortly after birth, while others may not show signs until later in life. The severity of the condition depends on the specific enzyme deficiency and its impact on the urea cycle.

  • Crigler-Najjar Syndrome

    Crigler-Najjar Syndrome is a rare genetic disorder that affects the metabolism of bilirubin, a substance produced by the normal breakdown of red blood cells. The condition is characterized by a deficiency in the enzyme responsible for converting bilirubin into a form that can be easily excreted from the body. As a result, bilirubin accumulates in the blood, leading to jaundice, which is a yellowing of the skin and eyes. There are two types of Crigler-Najjar Syndrome, with Type 1 being more severe than Type 2. The disease progresses with persistent jaundice and can lead to neurological complications if bilirubin levels become too high. The severity and progression of symptoms can vary between individuals.

  • Fibroinflammatory Liver Diseases

    Fibroinflammatory Liver Diseases encompass a range of conditions characterized by inflammation and fibrosis of the liver tissue. These diseases can result from various causes, including chronic infections, autoimmune disorders, and prolonged exposure to toxins. The inflammation leads to the activation of liver cells that produce fibrous tissue, causing scarring and affecting liver function. Over time, the liver may become stiff and less able to perform its normal functions. Symptoms can include fatigue, abdominal pain, and jaundice. The progression of these diseases can lead to significant liver damage if the underlying cause is not addressed.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2022-500251-22-00Protocol codePROLONGSTEMEstimated enrolment68 patientsSponsorCellaïon SA

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