Encoded Therapeutics Presents Data Showing That Children With Dravet Syndrome Experience Early, Substantial Neurodevelopment Deficits and Seizure Burden, at the American Epilepsy Society 2021 Annual Meeting

In addition to increased seizure frequency, the cognitive, language and motor domains are significantly affected by age two years, profoundly impacting functional abilities and an overall quality of life that worsen with age

ENVISION will help elucidate progression of Dravet syndrome during a critical period of child development

SOUTH SAN FRANCISCO, Calif.--()--Encoded Therapeutics today announced initial findings from its ENVISION natural history study of children living with SCN1A+ Dravet syndrome, a rare developmental and epileptic encephalopathy. Along with a substantial seizure burden, preliminary findings suggest the trajectory and timing by which children with Dravet syndrome deviate from neurotypical peers, showing that these children experience early and substantial delay in adaptive functioning, communication and socialization, worsening with age. These data and others from 46 study participants are being presented this weekend in Chicago at the American Epilepsy Society (AES) 2021 Annual Meeting.

“The primary goal of ENVISION is to elucidate Dravet syndrome progression during a critical period of child development by further defining the full range and evolution of disease manifestations, as well as their impact on young children and families living with this disease,” said Andreas Brunklaus, M.D., Consultant Pediatric Neurologist at the Royal Hospital for Children in Glasgow, United Kingdom. Dr. Brunklaus is a leading Dravet syndrome expert and presenting author of the ENVISION study data at the AES 2021 Annual Meeting. “ENVISION is generating a comprehensive contemporary dataset that evidences the profound neurodevelopmental stagnation in young children with Dravet syndrome. We hope that data over time will enable the community to refine our understanding of Dravet syndrome pathophysiology, paving the way for potential new disease-modifying medicines to be administered at a time point in young children's lives that could change the course of disease as we know it.”

One of the key findings to date is that, regardless of SCN1A variant type, there was global evidence of developmental stagnation as young as two years of age across domains of communication, language, socialization, and motor and adaptive functioning compared with neurotypical peers. Researchers also observed that seizure frequency continues to increase with age, despite the use of multiple and newer antiseizure medications.

“We have heard directly from families in the Dravet syndrome community that seizures and communication significantly impact quality of life, and that preservation of neurodevelopment is a key outcome sought from a gene therapy,” said Salvador Rico, M.D., Chief Medical Officer at Encoded. “These preliminary ENVISION data reinforce the ongoing impact that Dravet syndrome has on the lives of people and their families, and the need for a therapy that addresses the underlying cause of disease to positively affect both seizure and neurocognitive symptoms. Though we will gain further insights through longitudinal data as ENVISION advances, we believe that early administration of a potential one-time disease-modifying therapy such as ETX101 could yield the maximum benefit.”

“We are thankful to the children and families participating in ENVISION and to all the experts and health professionals involved in the study for their ongoing contributions that are critically important to understand the progression of Dravet syndrome,” Dr. Rico continued.

Encoded will share additional learnings from its ongoing DRAVET ENGAGE initiative, which aims to capture the Dravet syndrome patient community’s experiences and perspectives, in a separate presentation at the AES 2021 Annual Meeting. For a full list of Encoded’s presentations, click here. All abstracts are available on the AES website.

About ETX101
Encoded is developing ETX101 as a potential one-time, disease-modifying gene regulation therapy targeting the underlying cause of SCN1A+ Dravet syndrome, in hopes of addressing the full range of disease manifestations. In ETX101, a cell-selective regulatory element and a transgene coding for an engineered transcription factor are delivered in a clinically validated adeno-associated virus (AAV) capsid to upregulate, or increase, the expression of the endogenous SCN1A gene in the brain. This approach is expected to increase production of NaV1.1 protein and density of sodium channels in target neurons, leading to restored function. ETX101 has been granted Orphan Drug Designation and Rare Pediatric Disease Designation by the U.S. Food and Drug Administration. Encoded anticipates treating the first participant in the ENDEAVOR interventional trial in 2022.

About the ENVISION Natural History Study
ENVISION is an ongoing observational study of infants and children with SCN1A+ Dravet syndrome. This prospective natural history study is designed to further define the seizure, neurodevelopmental, motor and behavioral manifestations of SCN1A+ Dravet syndrome in children aged 6 to 60 months with SCN1A mutations. The study will examine these characteristics over two years using standardized assessments and will also explore the impact of the disease on parents/caregivers and healthcare resource utilization. These findings will help identify appropriate scales and endpoints to assess ETX101 safety and efficacy in clinical trials. For more information about ENVISION (NCT04537832), visit clinicaltrials.gov and search for “Encoded Therapeutics”.

About Dravet Syndrome
Dravet syndrome is a severe, lifelong disorder of the central nervous system that occurs in approximately 1 in 16,000 births worldwide, with the majority of cases resulting from loss-of-function mutations in the SCN1A gene. This rare developmental and epileptic encephalopathy equally affects people of both sexes and all races, manifesting in a wide array of symptoms. Frequent, prolonged and difficult-to-treat seizures typically begin in the first year of life of a previously healthy baby. Additional symptoms, such as cognitive delays, sleep abnormalities, motor impairment and behavioral difficulties, compound the effects of the disease when they appear, often in the second or third year of a child’s life. More information about Dravet syndrome can be found at www.dravetfoundation.org.

About Encoded Therapeutics
Encoded Therapeutics is creating one-time, disease-modifying gene therapies for pediatric central nervous system (CNS) disorders with its cell-selective targeting and regulation platform. The Encoded approach offers unprecedented gene specificity and cell selectivity to unlock novel opportunities by targeting a range of disease mechanisms. Encoded’s technology is compatible with any delivery system to control where and when therapeutic transgenes are expressed, thereby shaping the functionality of target cells and holding broader therapeutic potential beyond CNS disorders. For more information, please visit www.encoded.com, and follow us on LinkedIn, Twitter @EncodedTx and YouTube.

Contacts

Lynnea Olivarez
lolivarez@encoded.com
956-330-1917

Release Summary

Along with substantial seizure burden, ENVISION data suggest the trajectory and timing by which children with Dravet deviate from neurotypical peers.

Contacts

Lynnea Olivarez
lolivarez@encoded.com
956-330-1917