In short
Fosigotifator sodium tromethamine is an investigational medicine being developed for vanishing white matter disease, a rare genetic condition that affects the brain. One clinical trial is currently authorised to study this substance in people with the disease. The trial is a Phase 1 study with a planned enrollment of 52 participants, including both adults and children.
Key points
- Fosigotifator sodium tromethamine is an investigational substance with no marketing authorisation.
- It is being studied in vanishing white matter disease, a rare brain disorder.
- The authorised trial is a Phase 1 open-label study.
- The trial plans to enroll 52 participants, including adults and children.
- The main goal is to assess safety and tolerability of the substance.
- The trial also measures how the active compound moves through the body (pharmacokinetics).
What is fosigotifator sodium tromethamine?
Fosigotifator sodium tromethamine is an investigational substance being developed by AbbVie Limited. It is also known by the development code ABBV-CLS-7262. The substance has no marketing authorisation, meaning it is not yet approved as a medicine.
The European Medicines Agency (EMA) has agreed a paediatric investigation plan for fosigotifator sodium tromethamine, which means the company has committed to studying the substance in children as well as adults. This plan was modified on 7 April 2025.
How does fosigotifator work?
Fosigotifator is a prodrug, meaning it is an inactive form that the body converts into an active compound. The pharmacologically active compound is called A-1684909. After fosigotifator is taken, the body transforms it into A-1684909, which is the substance that has an effect in the body.
The trial measures the plasma and cerebrospinal fluid (CSF) concentrations of A-1684909 to understand how much of the active compound reaches the blood and the fluid around the brain and spinal cord.
Which conditions is fosigotifator studied for?
- Vanishing white matter disease — a rare genetic condition in which the white matter of the brain, which contains nerve fibres, progressively breaks down. The trial studies fosigotifator in adults and children with this disease.
How is fosigotifator given?
Fosigotifator is given by mouth. In the trial, the substance is administered as an oral formulation.
What do the clinical trials show?
One trial of fosigotifator is currently authorised. It is an open-label exploratory Phase 1 study, meaning all participants know they are receiving the substance and the main purpose is to gather early information about safety and how the body handles the drug.
The trial plans to enroll 52 participants with vanishing white matter disease, including both adults and children. The study is interventional, meaning participants receive the substance as part of the research.
The primary outcomes measured include adverse events and serious adverse events during the safety evaluation period, vital signs, electrocardiograms (ECGs), clinical laboratory tests, and suicidality assessments. The trial also measures plasma concentrations of A-1684909 from baseline up to week 96, and CSF concentrations at weeks 12, 48, and 96.
Pharmacokinetic parameters of A-1684909 are measured following dosing at study day 14 for certain groups. These parameters include the maximum concentration in the blood (Cmax), the time to reach that maximum (Tmax), the total exposure over 24 hours (AUC0-24h), the lowest concentration before the next dose (Ctrough), and the half-life (t1/2), which is the time it takes for half of the substance to leave the body.
What side effects are known?
No side effect information is available from the provided sources. The authorised trial is designed to assess safety and tolerability, including adverse events and serious adverse events, but results have not been reported in the provided data.