Design Therapeutics (DSGN) Piper Sandler 36th Annual Healthcare Conference summary

FA program updates and clinical plans

• DT-216 v2 addresses prior limitations by improving exposure duration and resolving injection site safety issues seen with the original formulation.

• Healthy volunteer studies (SAD only) are planned for the first half of 2025, using both IV and subcutaneous routes to confirm PK and safety improvements.

• New regulatory filings are required due to the significantly different exposure profile of DT-216 v2.

• Patient studies will be designed based on healthy volunteer data, with the goal of achieving sustained frataxin increases.

• Robust assays for frataxin measurement have been developed, leveraging recent advances and expert input.

Regulatory and scientific landscape for FA

• Approval of Skyclarys validates the commercial potential in Friedreich's ataxia but does not address frataxin levels.

• Regulatory agencies are seen as sympathetic to the unmet need and monogenic disease drivers, but expectations for concessions remain cautious.

• Natural history data suggest that increasing frataxin to carrier levels could have significant clinical benefit.

Fuchs program progress and strategy

• Fuchs dystrophy affects millions, with most cases linked to a single TCF4 gene mutation; no disease-modifying therapies currently exist.

• DT-168 eyedrop targets the disease-causing mutation and has shown reversal of pathogenic RNA foci in patient-derived cells.

• Phase 1 healthy volunteer study is underway to assess safety and tolerability, with results expected in the first half of 2025.

• An observational study in 200 genetically confirmed patients is informing endpoint selection and phase 2 design.

• The competitive landscape is open, with no other companies targeting the genetic driver of Fuchs.