Thryv Therapeutics Inc, a Canada-based, clinical-stage biotechnology company advancing novel serum glucocorticoid inducible kinase 1 (SGK1) inhibitors for inherited cardiac arrhythmias, cardiometabolic diseases, and cardiomyopathies, on Wednesday announced key development milestones for its THRV-1268 clinical programme.

Patient dosing has commenced in the Phase 2/3 Wave II clinical study evaluating THRV-1268 in patients with genetically confirmed Long QT Syndrome Type 2, and the US Food and Drug Administration (FDA) has granted Fast Track Designation to THRV-1268 for the treatment of Long QT Syndrome Type 2 and Type 3.

Enrolment of the Wave II study remains on track with the company's expectations for delivering initial data in the fourth quarter of 2026.

Wave II is a multicentre, Phase 2/3 trial enrolling patients with genetically confirmed Long QT Syndrome Type 2. The primary endpoint will assess the safety and efficacy of two dose levels of THRV-1268 over a 12-week period, measured by change in QTcF over six hours, together with evaluations of cardiac rhythm stability, safety, and tolerability.

Initially, participants in the Wave II study will receive the study drug as an oral suspension, selected to accelerate data collection for the paediatric formulation, for 12 weeks, with the option to transition to an adult tablet and continue therapy for up to one year.

Fast Track Designation is intended to facilitate the development and expedited review of investigational therapies that address serious conditions with unmet medical needs. The designation enables more frequent interactions with the FDA and, if relevant criteria are met, potential eligibility for Rolling Review, Priority Review, and Accelerated Approval.