Stoke Hits Key Enrollment Milestone: Phase 3 EMPEROR Fully Randomized

What happened

Stoke Therapeutics announced completion of enrollment of 162 patients in the Phase 3 EMPEROR study of zorevunersen for Dravet syndrome, meeting the critical June 30 deadline. This milestone eliminates a key timeline risk and supports the company's guidance for a mid-2027 data readout, which is necessary to complete a rolling NDA submission. However, we still await confirmation that European enrollment will finish by Q3 2026 and that the safety profile remains clean, particularly regarding CSF protein elevations. Active ATM issuance (up to $150M capacity) continues to dilute existing shareholders, and the stock price already discounts a clean execution path. While this is a positive de-risking event, it does not change the binary nature of the Phase 3 outcome, and we maintain our cautious stance pending further data.

Implication

The confirmed randomization of 162 patients aligns with the base case scenario (50% probability, $35 implied value) and removes a major near-term risk. However, we are not upgrading to Buy because (1) Europe enrollment must still complete by Q3 2026 to keep the mid-2027 readout on track, (2) any recharacterization of CSF protein elevations toward clinically meaningful events would impair the approvability thesis, and (3) ongoing ATM dilution (~2.6M shares in Q1'26) will continue to weigh on per-share value. Investors should use any strength to trim positions, with an attractive re-entry at $28 and a re-assessment after the Europe enrollment update and next safety disclosure.

Thesis delta

The key near-term risk—failure to randomize the final patient by June 30, 2026—has been resolved, removing the most likely trigger for a downside move. This shifts focus to the remaining two thesis breakers: Europe enrollment completion by Q3 2026 and absence of serious safety signals from CSF protein elevations. While the base case probability increases, the thesis does not materially improve enough to upgrade from Wait; we need to see the next 90-day checkpoints passed cleanly.