Thryv Therapeutics, a clinical-stage biotechnology company focused on developing novel Serum Glucocorticoid Inducible Kinase 1 (SGK1) inhibitors, has announced the initiation of its Wave II clinical study, a pivotal Phase II/III trial in adults diagnosed with Long QT Syndrome Type 2 (LQTS2). The study marks a milestone in the company’s efforts to advance disease-modifying therapies for rare and life-threatening cardiac arrhythmias.

Wave II is designed to evaluate the safety and efficacy of THRV-1268, an orally administered SGK1 inhibitor, and represents an important step toward a potential first FDA-approved therapy that directly targets QT prolongation in LQTS2. Long QT Syndrome is a rare inherited disorder associated with abnormal heart rhythms and an increased risk of sudden cardiac events, with limited treatment options currently available.

The initiation of Wave II builds on encouraging results from Thryv’s Wave I clinical program and a subsequent Phase I study, both of which demonstrated the QT-shortening potential of SGK1 inhibition in acquired and congenital Long QT Syndrome Types 2 and 3. In the Wave I study, treatment with Thryv’s earlier SGK1 inhibitor, LQT-1213, resulted in clinically meaningful reductions in QTc intervals while maintaining a favorable safety profile, including when used alongside standard-of-care therapies.

The Wave II study follows a two-part design, consisting of a 12-week dose-escalation phase followed by a six-week fixed-dose phase using a selected dose of THRV-1268. The primary efficacy endpoint is the mean change from baseline in QTc Area Under the Curve (AUC) in patients with genetically confirmed LQTS2 and a baseline QTc greater than 480 milliseconds.

With the launch of Wave II, Thryv Therapeutics aims to further validate SGK1 inhibition as a novel therapeutic approach and accelerate the development of a first-in-class treatment option for patients and families affected by Long QT Syndrome Type 2.