Shares of Stoke Therapeutics (NASDAQ:STOK) fell about 18% after the company outlined revised timelines for its Phase 3 EMPEROR trial evaluating zorevunersen as a treatment for Dravet syndrome.
The biotechnology company said it now expects to complete enrollment of 150 patients in the second quarter of 2026, with top-line data anticipated in mid-2027. Stoke also plans to begin a rolling New Drug Application (NDA) submission to the U.S. Food and Drug Administration in the first half of 2027.
While management described the update as reflecting “accelerated timelines,” investors appeared to focus on what they viewed as a later-than-expected data readout compared with earlier expectations. Stoke noted that discussions with the FDA are ongoing following a recent multidisciplinary meeting to explore potential expedited regulatory pathways, although no immediate changes to the development plan were agreed.
“The rate of enrollment in the Phase 3 EMPEROR study is highly encouraging and supports the significant need for a disease-modifying treatment for Dravet syndrome,” said Ian F. Smith, Chief Executive Officer and Director of Stoke Therapeutics.
The company said nearly 330 patients worldwide have been identified as potential candidates for the study. Of these, around 60 patients are currently in formal screening, while another 60 have already been randomized and are receiving treatment.
Stoke is developing zorevunersen in collaboration with Biogen (NASDAQ:BIIB), positioning it as a potential first-in-class disease-modifying therapy for Dravet syndrome, a rare and severe form of epilepsy.
Stoke also disclosed that it held approximately $391.7 million in cash, cash equivalents and marketable securities as of December 31, 2025. Together with eligible proceeds from the Biogen partnership, the company said this funding is expected to support operations into 2028.