Stoke Therapeutics (STOK) 25th Annual Needham Virtual Healthcare Conference summary

Key clinical insights and data

• Lead asset zorevunersen shows ~75% sustained seizure reduction in Dravet syndrome patients, maintained for up to three years in open-label extension studies, on top of standard anti-seizure medications.

• Significant improvements in cognition and behavior, especially in expressive and receptive communication, have been observed and measured by Vineland-3, with gains sustained over multiple years.

• The drug is well-tolerated with high patient retention in long-term studies; no significant clinical issues related to CSF protein elevations have been observed.

• Publication of phase II data in NEJM, along with supportive editorial and videos, has enhanced credibility and enthusiasm among clinicians, payers, and investors.

• Longitudinal data, including up to five years at time of approval, is expected to be a key differentiator for regulatory and commercial success.

Regulatory and development updates

• Ongoing discussions with the FDA regarding expedited approval; current focus is on completing the phase III EMPEROR trial due to minimal timeline advantage for accelerated filing.

• Phase III enrollment expected to complete in Q2 2026, with top-line data anticipated mid-2027 and potential approval as early as Q4 2027 via rolling NDA submission.

• EMPEROR trial is a double-blind, randomized, sham-controlled study with 150-160 patients; primary endpoint is seizure reduction at week 28, secondary endpoints include Vineland-3 domains at week 52.

• Study is powered to detect clinically meaningful changes in expressive and receptive communication, with high confidence based on prior data and natural history comparisons.

• Regulatory agencies are aligned on primary endpoint for approval; secondary endpoints and long-term data are critical for label strength and payer acceptance.

Commercial opportunity and strategy

• Addressable market in core geographies (US, UK, EU4, Japan) estimated at 35,000–40,000 patients, with 6,000 immediately addressable in the US at launch.

• Additional efforts underway to identify undiagnosed and adult patients, including screening campaigns.

• Long-term OLE data expected to be included in Section 14 of the label, supporting promotion, access, and pricing, with Spinraza cited as a precedent.

• Clinicians and payers value the durability and breadth of benefit shown in long-term data, which is expected to drive adoption and reimbursement.

• Commercial positioning focuses on disease modification, not just seizure reduction, to differentiate from existing therapies.