The US Food and Drug Administration (FDA) has granted orphan drug designation to Stoke Therapeutics’ antisense oligonucleotide, STK-001, a new therapy for severe and progressive genetic epilepsy Dravet syndrome.
Orphan status is granted by the FDA’s Office of Orphan Drug Products to support the development of medicines for safe treatment, diagnosis or prevention of rare diseases or disorders.
Recipients of orphan drug designation will receive various development incentives, which include tax credits for qualified clinical testing, an exemption from FDA application fees.
The companies will also receive marketing exclusivity for seven years in the US, upon approval of the drug.
Stoke Therapeutics chief medical officer Barry Ticho said: “Our goal with STK-001 is to slow or even stop disease progression by treating the underlying cause of Dravet syndrome.
“STK-001 is designed to selectively upregulate one allele of the SCN1A gene to restore the protein expression to near-normal levels. We are on track to submit our investigational new drug application for STK-001 to the FDA in early 2020 and to begin a Phase I/II clinical study in the first half of the year.”
The company believes that the investigational new medicine STK-001 has the potential to be the first disease-modifying therapy to address the underlying genetic cause of Dravet syndrome.
By upregulating NaV1.1 protein expression from the non-mutant (wild type) copy of the SCN1A gene, the drug will restore physiological NaV1.1 levels.
This minimises the occurrence of seizures, as well as significant non-seizure comorbidities. Stoke has generated preclinical data demonstrating proof-of-mechanism for STK-001.
Dravet syndrome, which begins within the first year of life, is difficult to treat and has a poor long-term prognosis. It affects about 35,000 people across the US, Canada, Japan, Germany, France and the UK.