– New data showed improvements in cognition and behavior during the first year of treatment with additional increases demonstrated as treatment continued –
– Clinical effects observed across the Phase 1/2a and open-label extension studies (OLEs) of zorevunersen are a first in the treatment of Dravet syndrome and support plans for the Company’s Phase 3 registrational study –
– Zorevunersen generally well-tolerated across the studies –
– Data presented for the first time at the 15th European Epilepsy Congress (EEC) –
BEDFORD, MA, USA I September 10, 2024 I
Stoke Therapeutics, Inc.
(Nasdaq: STOK), a biotechnology company dedicated to restoring protein expression by harnessing the body’s potential with RNA medicine, today announced highlights from presentations at the
15th European Epilepsy Congress (EEC)
related to the Company’s work to develop the first disease-modifying medicine for Dravet syndrome. Zorevunersen (STK-001) data showing substantial and sustained reductions in seizures and meaningful improvements in multiple measures of cognition and behavior were presented for the first time in a scientific forum. New data from an analysis of patients treated in the Phase 1/2a ADMIRAL study showed improvements in cognition and behavior during the first year of treatment with additional increases demonstrated as treatment continued. In addition, data from a two-year natural history study presented at the meeting showed that despite treatment with standard-of-care antiseizure medications, patients with Dravet syndrome continued to have high seizure rates and plateaued in their neurodevelopment, resulting in a widening gap in development compared to their neurotypical peers.
Dravet syndrome is a severe and progressive genetic epilepsy characterized by frequent, prolonged and refractory seizures beginning within the first year of life. The disease is classified as a developmental and epileptic encephalopathy due to the developmental delays and cognitive impairment associated with the disease. There are no approved disease-modifying therapies for people living with Dravet syndrome, which occurs in one out of 16,000 babies.
“The profound reductions in seizures and improvements in cognition and behavior seen in these studies open the door to a new era in the treatment of Dravet syndrome and provide convincing evidence of the potential for zorevunersen as the first disease-modifying medicine,” said Helen Cross, MB ChB, Ph.D., Professor, The Prince of Wales’s Chair of Childhood Epilepsy and Director of University College London Great Ormond Street Institute of Child Health, Honorary Consultant in Paediatric Neurology, and the ADMIRAL study lead investigator. “We are very encouraged by the data from the Phase 1/2a ADMIRAL study that showed substantial reductions in seizures and meaningful improvements in cognition and behavior within the first year of treatment. As patients continue treatment in the open-label extension study we see even greater improvements in their cognition and behavior, which is remarkable.”
“The two-year natural history data provide clear evidence that current anti-seizure medicines are insufficient because even with the best available medicines patients still suffer from continued high rates of seizures and, as these children age, their development falls further behind their neurotypical peers,” said Barry Ticho, M.D., Ph.D., Chief Medical Officer of Stoke Therapeutics. “Data from our clinical studies of zorevunersen provide a glimpse into the future of treatment for patients with Dravet syndrome. The data from our studies suggest that by restoring protein expression with zorevunersen, we may be able to substantially reduce seizures beyond any benefit patients are currently receiving from anti-seizure medicines. Even more promising is the potential to improve cognition and behavior, which has never before been demonstrated in a clinical study of Dravet syndrome. These data provide confidence in our plans for a Phase 3 registrational study, including the dose regimen and clinical endpoints.”
Highlights from the Company’s presentations at the meeting include:
All presentations are available for download on the Stoke Therapeutics website under the Investors & News tab.
About Dravet Syndrome
Dravet syndrome is a severe and progressive genetic epilepsy characterized by frequent, prolonged and refractory seizures, beginning within the first year of life. Dravet syndrome is difficult to treat and has a poor long-term prognosis. Complications of the disease often contribute to a poor quality of life for patients and their caregivers. The effects of the disease go beyond seizures and often include intellectual disability, developmental delays, movement and balance issues, language and speech disturbances, growth defects, sleep abnormalities, disruptions of the autonomic nervous system and mood disorders. The disease is classified as a developmental and epileptic encephalopathy due to the developmental delays and cognitive impairment associated with the disease. Compared with the general epilepsy population, people living with Dravet syndrome have a higher risk of sudden unexpected death in epilepsy, or SUDEP. There are no approved disease-modifying therapies for people living with Dravet syndrome. One out of 16,000 babies are born with Dravet syndrome, which is not concentrated in a particular geographic area or ethnic group.
About Zorevunersen (STK-001)
Zorevunersen is an investigational new medicine for the treatment of Dravet syndrome currently being evaluated in ongoing clinical trials. Stoke believes that zorevunersen, a proprietary antisense oligonucleotide (ASO), has the potential to be the first disease-modifying therapy to address the genetic cause of Dravet syndrome. Zorevunersen is designed to upregulate NaV1.1 protein expression by leveraging the non-mutant (wild-type) copy of the
SCN1A
gene to restore physiological NaV1.1 levels, thereby reducing both occurrence of seizures and significant non-seizure comorbidities. Zorevunersen has been granted orphan drug designation by the FDA and the EMA, and rare pediatric disease designation by the FDA as a potential new treatment for Dravet syndrome.
About the U.S. Studies: MONARCH (Phase 1/2a) and SWALLOWTAIL (OLE)
The MONARCH study was a Phase 1/2a open-label study of children and adolescents ages 2 to 18 who have an established diagnosis of Dravet syndrome and have evidence of a genetic mutation in the
SCN1A
gene. The primary objectives for the study were to assess the safety and tolerability of zorevunersen (STK-001), as well as to determine the pharmacokinetics in plasma and exposure in cerebrospinal fluid. A secondary objective was to assess the efficacy as an adjunctive antiepileptic treatment with respect to the percentage change from baseline in convulsive seizure frequency.
Following completion of MONARCH, patients who met study entry criteria were eligible to continue treatment in SWALLOWTAIL, an open-label extension (OLE) study designed to evaluate the long-term safety and tolerability of repeat doses of zorevunersen. The study is also evaluating the long-term effects of zorevunersen on convulsive seizure frequency and on behavior, cognition and overall quality of life. Dosing in SWALLOWTAIL is ongoing.
About the UK Studies: ADMIRAL (Phase 1/2a) and LONGWING (OLE)
The ADMIRAL study was a Phase 1/2a open-label study of children and adolescents ages 2 to <18 who have an established diagnosis of Dravet syndrome and have evidence of a genetic mutation in the
SCN1A
gene. The primary objectives for the study were to assess the safety and tolerability of multiple doses of zorevunersen (STK-001), as well as to determine the pharmacokinetics in plasma and exposure in cerebrospinal fluid. A secondary objective was to assess the effect of multiple doses of zorevunersen as an adjunctive antiepileptic treatment with respect to the percentage change from baseline in convulsive seizure frequency. Overall clinical status and quality of life were secondary endpoints of ADMIRAL.
Following completion of ADMIRAL, patients who met study entry criteria were eligible to continue treatment in LONGWING, an open-label extension (OLE) study designed to evaluate the long-term safety and tolerability of repeat doses of zorevunersen. The study is also evaluating the long-term effects of zorevunersen on convulsive seizure frequency and on behavior, cognition and overall quality of life. Dosing in LONGWING is ongoing.
About the BUTTERFLY Observational Study
The BUTTERFLY study was a multicenter, longitudinal, prospective, observational study of children and adolescents ages 2 to 18 who have been diagnosed with Dravet syndrome as a result of an
SCN1A
gene mutation. This study was designed to evaluate neurodevelopmental status and change from baseline to 24 months. Secondary and exploratory endpoints in the study evaluated changes in other disease measures, including seizures and additional non-seizure comorbidities. No investigational medications or other treatments were provided. Participants continued to receive their usual care, including anti-seizure medications, and were observed for up to two years. The study was conducted at approximately 20 sites in the United States. Two-year results were presented at the American Epilepsy Society Annual Meeting in December 2023 and showed that, on average, patients experienced no meaningful improvement in convulsive seizure frequency and exhibited widening gaps in cognition and behavior compared to neurotypical peers, despite treatment with the best available anti-seizure medicines.
About Stoke Therapeutics
Stoke Therapeutics (Nasdaq: STOK), is a biotechnology company dedicated to restoring protein expression by harnessing the body’s potential with RNA medicine. Using Stoke’s proprietary TANGO (Targeted Augmentation of Nuclear Gene Output) approach, Stoke is developing antisense oligonucleotides (ASOs) to selectively restore protein levels. Stoke’s first compound, zorevunersen (STK-001), is in clinical testing for the treatment of Dravet syndrome, a severe and progressive genetic epilepsy. Dravet syndrome is one of many diseases caused by a haploinsufficiency, in which a loss of ~50% of normal protein levels leads to disease. Stoke is pursuing the development of STK-002 for the treatment of autosomal dominant optic atrophy (ADOA), the most common inherited optic nerve disorder. Stoke’s initial focus is haploinsufficiencies and diseases of the central nervous system and the eye, although proof of concept has been demonstrated in other organs, tissues, and systems, supporting its belief in the broad potential for its proprietary approach. Stoke is headquartered in Bedford, Massachusetts with offices in Cambridge, Massachusetts. For more information, visit
https://www.stoketherapeutics.com/
.
SOURCE:
Stoke Therapeutics
