Dravet efficacy wanes for Stoke

Stoke Therapeutics' antisense oligonucleotide STK-001 reduces the frequency of convulsive seizures in Dravet syndrome patients – but not as much as previously. Updated data released today show that when results from two phase 1/2a paediatric studies of STK-001, Monarch and Admiral, are combined, seizure frequency was reduced by 18% between day 29 after the first dose and three months after the last dose. This was seen in 16 patients who had received three monthly 45mg doses. An earlier cut from the same trials, released in December, showed that this same dose had caused seizure reduction of 55% at the same time point, albeit in just six patients. In the 70mg cohort in Admiral, seizure frequency dropped by 42% – but this group was only eight patients strong. Further data ought to come in the first quarter of 2024. And Stoke has other challenges: the trials are on partial clinical hold in the US, and patients there may only receive a single 70mg dose of STK-001. The latest update detailed serious adverse reactions attributed to STK-001 in a patient receiving multiple 70mg doses. Stoke opened down 31%.