In short
Relutrigine (also known as PRAX-562) is an investigational medicine being studied for SCN2A and SCN8A developmental and epileptic encephalopathies, rare genetic conditions that cause severe seizures in children. One Phase 2 trial with 80 planned participants is currently authorised in the EU Clinical Trials Information System. The substance has orphan drug designation from the US FDA for SCN2A developmental and epileptic encephalopathy.
Key points
- Relutrigine is an investigational substance with no marketing authorisation in the product records.
- It is being studied in a Phase 2 trial for SCN2A and SCN8A developmental and epileptic encephalopathies.
- The trial plans to enrol 80 paediatric participants.
- The trial has orphan drug designation from the US FDA for SCN2A developmental and epileptic encephalopathy.
- The medicine is given as a powder for oral suspension, by mouth or through a feeding tube.
- The trial measures safety and tolerability as well as changes in monthly motor seizure frequency.
What is relutrigine?
Relutrigine is a chemically synthesised substance that is being developed as an investigational medicine. It has no marketing authorisation in the product records, meaning it is not yet approved as a medicine for routine clinical use. The substance is also known by its development code PRAX-562. The company developing relutrigine is Praxis Precision Medicines Inc.
Relutrigine has been granted orphan drug designation by the US Food and Drug Administration (FDA) for the treatment of SCN2A developmental and epileptic encephalopathy, a designation given to medicines being developed for rare diseases. The designation was granted on 27 April 2021. The FDA has not approved relutrigine for this orphan indication.
How does relutrigine work?
The available sources do not describe the mechanism of action of relutrigine in detail. The substance is being studied in conditions caused by changes in the SCN2A and SCN8A genes, which provide instructions for making sodium channels in nerve cells. Sodium channels help control the electrical activity of nerve cells, and changes in these genes can lead to severe seizures. The clinical trial is designed to explore the safety, tolerability, efficacy and pharmacokinetics of relutrigine in children with these conditions. Pharmacokinetics refers to how the body absorbs, distributes, breaks down and removes a medicine.
Which conditions is relutrigine studied for?
- SCN2A developmental and epileptic encephalopathy (SCN2A DEE) — a rare genetic condition caused by changes in the SCN2A gene that leads to severe, early-onset seizures and developmental problems.
- SCN8A developmental and epileptic encephalopathy (SCN8A DEE) — a rare genetic condition caused by changes in the SCN8A gene that also leads to severe seizures and developmental difficulties.
Relutrigine has orphan drug designation from the US FDA specifically for SCN2A developmental and epileptic encephalopathy.
How is relutrigine given?
Relutrigine is prepared as a powder for oral suspension. In the clinical trial, it is given by mouth, or through a nasogastric tube or a percutaneous endoscopic gastrostomy tube. A nasogastric tube is a thin tube passed through the nose into the stomach, and a percutaneous endoscopic gastrostomy tube is a feeding tube placed directly into the stomach through the skin. The trial also includes a placebo powder for oral suspension as a comparison.
What do the clinical trials show?
One Phase 2 trial of relutrigine is registered in the EU Clinical Trials Information System. The trial is authorised, meaning it has received the necessary approvals to proceed. It is a double-blind, randomised trial, which means that neither the participants nor the researchers know who is receiving relutrigine and who is receiving placebo, and participants are assigned to treatment groups by chance.
The trial plans to enrol 80 paediatric participants with SCN2A and SCN8A developmental and epileptic encephalopathies. The study has two parts. Part A has four cohorts. Cohorts 1 and 2 are randomised and double-blind and evaluate the safety and tolerability of relutrigine. Cohorts 3 and 4 are also randomised and double-blind and assess the effect of relutrigine on the frequency of countable motor seizures. Part B is an open-label extension, meaning that all participants know they are receiving relutrigine, and it evaluates the long-term safety and tolerability of the medicine.
The primary outcome measures differ between the cohorts. In Part A Cohorts 1 and 2 and in Part B, the main measure is the incidence and severity of treatment-emergent adverse events, which are side effects that appear during treatment. In Part A Cohorts 3 and 4, the main measure is the change from baseline in monthly motor seizure frequency, meaning the number of seizures involving movement that occur over a 28-day period.
What side effects are known?
The available sources do not provide a list of side effects for relutrigine. The Phase 2 trial is designed to evaluate the safety and tolerability of the medicine, including the incidence and severity of treatment-emergent adverse events. Information on side effects will become available as the trial progresses and results are reported.