The UK Medicines and Healthcare products Regulatory Agency (MHRA) has approved Encoded Therapeutics’ clinical trial authorisation application for the Phase I/II EXPEDITION study of ETX101 for SCN1A+ Dravet syndrome.

The trial will enrol children aged six months to four years with SCN1A+ Dravet syndrome.

It will evaluate up to two doses of ETX101 in four participants in the UK.

The trial's primary objectives are to assess ETX101's tolerability and safety, with the aim of evaluating initial efficacy and selecting the appropriate therapeutic dose.

The EXPEDITION trial is due to begin in the UK later this year and will be conducted concurrently with the ENDEAVOR and WAYFINDER trials, which are being carried out in the US and Australia respectively.

ETX101 is being developed as a single-time, disease-modifying gene regulation therapy that acts on the underlying cause of SCN1A+ Dravet syndrome.

The therapy aims to boost the production of NaV1.1 protein sodium channels in neurons, potentially restoring brain function and addressing the range of symptoms associated with Dravet syndrome.

Apart from the MHRA approval, Encoded Therapeutics has received regulatory clearances for an investigational new drug application in the US and a clinical trial approval in Australia.

The EXPEDITION study is part of the POLARIS global clinical development programme.

Dravet syndrome is a developmental and epileptic encephalopathy characterised by a range of clinical symptoms, including treatment-resistant seizures and neurodevelopmental delays.

Encoded Therapeutics chief medical officer Sal Rico said: “We believe ETX101 has the potential to deliver transformative benefit in multiple disease domains and have designed our clinical programme to efficiently assess its impact on affected infants and young children.

“We are committed to working closely with our highly experienced investigators to expeditiously enrol affected children in an effort to advance therapeutic options for people living with Dravet syndrome.”