Encoded Therapeutics has raised $275m in a Series F financing round to advance development of its disease-modifying therapy (DMT) for Dravet syndrome, with an eye also on initiating clinical trials for another gene therapy candidate in its pipeline.
The round was co-led by GV and another healthcare fund, with participation from big investment players such as ARCH Venture Partners, Janus Henderson Investors, and Farallon Capital Management, among others.
The neurology-focused biotech will first put proceeds towards a pivotal trial with ETX101 in infants and young children with SCN1A+ Dravet syndrome, along with an expansion study in children and adolescents up to 18 years of age. More than 90% of Dravet syndrome cases are caused by a loss-of-function in this gene, which causes a severe form of epilepsy and long-lasting seizures accompanied by developmental delays.
ETX101 is a one-time gene therapy that selectively increases the expression of a healthy copy of SCN1A+, targeting the underlying root genetic cause of the syndrome. The candidate has already demonstrated positive data in the Phase I/II POLARIS study. Following a single administration at the third dose level, ETX101 cut monthly seizures by up to 79% in patients who completed a year of follow-ups.
“The interim Phase I/II POLARIS data we recently shared at the European Epilepsy Congress demonstrate substantial and sustained seizure frequency reductions alongside encouraging developmental gains. This progress strengthens our conviction in ETX101 and the potential of our approach to meaningfully alter the course of Dravet syndrome,” said Kartik Ramamoorthi, Encoded’s CEO.
“With pivotal development underway, this financing gives us the resources to advance ETX101 toward registration while continuing to build the capabilities and pipeline that will define Encoded’s next stage,” he added.
With the Series F financing, Encoded is racing to market the first DMT for Dravet syndrome. The biotech is not alone in the hunt, however. Biogen signed a deal worth up to $550m for certain regional rights to Stoke Therapeutics’ zorevunersen in all territories outside Canada, Mexico, and the US. Stoke’s asset is an antisense oligonucleotide that instructs cells to make a healthy copy of the SCN1A gene in Dravet syndrome patients. A readout from the companies’ Phase III EMPEROR study is expected in Q3 2027.
There is no exact data available for the number of Dravet syndrome patients in the US, though it is estimated to affect one in every 16,000 live births. It accounts for roughly 0.17% of all epilepsy cases, according to the National Organization for Rare Disorders (NORD).
It’s not just ETX101 that will benefit from the Series F tranche. Funding will also support commercial scale-up of internal GMP manufacturing capabilities and pipeline advancement, including advancing another asset dubbed ETX301 toward an Investigational New Drug (IND) submission for post-amputation neuroma pain in 2027.
Editor's note: This article was updated on 11 September to correct the readout date for the Phase III EMPEROR study.
