Stoke and Biogen report Dravet therapy data

• Stoke Therapeutics (NASDAQ:STOK) and Biogen (NASDAQ:BIIB) reported long-term clinical data for investigational Dravet syndrome therapy zorevunersen.
• Four-year extension data showed sustained seizure reductions and improvements in cognition and behavior compared with open-label baseline.
• The Phase 3 EMPEROR trial completed enrollment, with data expected in Q3 2027 ahead of a planned U.S. NDA submission.

Stoke Therapeutics (NASDAQ:STOK) and Biogen (NASDAQ:BIIB) reported long-term clinical data for investigational Dravet syndrome treatment zorevunersen from Phase 1/2a and open-label extension studies.

The companies reported four-year extension data showing durable seizure reductions and statistically significant improvements in cognition and behavior at years one through four compared with open-label baseline measurements.

Stoke Therapeutics and Biogen reported that exploratory analyses showed reductions in severe seizure types through three years and improvements in quality-of-life measures through 28 months of treatment.

The companies reported that zorevunersen was generally well tolerated across more than 930 administered doses, with some patients receiving treatment for more than five years, while elevated cerebrospinal fluid protein levels were observed without serious clinical manifestations or hydrocephalus.

The Phase 3 EMPEROR trial has completed enrollment in the United States, United Kingdom, Japan, and Europe, including 162 patients in the primary analysis population and 34 patients in Europe.

Zorevunersen is an investigational therapy being developed for Dravet syndrome, a rare genetic epilepsy disorder, with Stoke and Biogen planning a Phase 3 data readout in the third quarter of 2027 to support a planned rolling U.S. NDA submission in the second half of 2027.