Stoke Therapeutics has listed on the Nasdaq in the US, raising $142m to advance its pipeline of drugs that aim to restore missing protein expression in genetic diseases.
Around $39m of the total will be used to advance its lead candidate STK-001 into a phase 3 trial for Dravet syndrome, a rare and severe form of epilepsy that in around 85% of cases is caused by a mutation in the SCN1A gene that leads to the loss of a sodium ion channel usually found on neurons.
Stoke’s therapeutic approach – called TANGO – is based on antisense drugs that are used to up-regulate the production of messenger RNA, which in turn produce proteins.
It is focusing on diseases involving one mutated and one functional gene in a pair, known as autosomal dominant haploinsufficiencies, which put simply means the patient is producing only half as much protein as is needed.
The biotech says its antisense drugs can increase the levels of functional mRNA, restoring protein production to “near normal levels” and tackling the underlying cause of disease.
In Stoke’s IPO prospectus filed with the Securities & Exchange Commission (SEC), the company says it will file for approval to start trials of STK-001 early in 2020 and will start a phase 1/2 trial before the end of that year with results due in 2021.
STK-001’s development programme will benefit from the pioneering work by cannabidiol-based therapies for Dravet’s syndrome, which have “informed the clinical and regulatory pathways” for drugs seeking to treat the disorder, which affects roughly 35,000 patients across the US, Canada, Japan, Germany, France and the UK.
According to a 2017 study, more than 90% of Dravet syndrome patients have incomplete seizure control with existing antiepileptic therapies.
Another $34m to $37m will go towards R&D into additional TANGO candidates, with a second candidate to treat an additional genetic disease for due to be nominated preclinical development by the first half of 2020, says the prospectus.
Stoke says it has identified around 2,900 monogenic, or single gene, diseases which it believes could be treatable with TANGO drugs.