A Phase 2/3, Two-part, Dose-ranging, Adaptive Study to Evaluate Efficacy and Safety of THRV-1268 in Participants Diagnosed With Long QT Syndrome Type 2 (LQTS 2)
The goal of this clinical trial is to learn whether the study drug THRV-1268 can safely and effectively shorten the QT interval in people diagnosed with Long QT Syndrome Type 2 (LQTS 2). The study will also learn about the safety and tolerability of THRV-1268 at different doses. The main questions this study aims to answer are: Does THRV-1268 reduce the QTc interval (a measure of the heart's electrical recovery time)? What side effects or medical problems occur when participants take THRV-1268? Which dose of THRV-1268 works best and is safest? Participants will: Complete a 3-week observation period with ECG and Holter monitoring to establish baseline QTc measurements Take THRV-1268 tablets twice daily at two dose levels for 6 weeks (Part A) or be randomly assigned to a dose group for 6 weeks (Part B) Have clinic visits and tests to monitor safety and changes in their heart rhythm May continue taking THRV-1268 for up to 1 year for ongoing safety and efficacy evaluation Researchers will compare changes in QTc over time and evaluate side effects to determine whether THRV-1268 can help reduce the risk of abnormal heart rhythms and sudden cardiac events in people with LQTS 2.
• Male and female participants over 15 years of age at Screening (at least the first 5 participants enrolled in Part A must be 18 years of age or older).
• LQTS 2 genotype: Demonstration of KCNH2 mutation by clinical laboratory test result that is autosomal dominant (heterozygous) and considered to be pathologic or likely pathologic can be included after approval from the sponsor medical monitor or qualified delegate.
• QTcF interval \>480 ms and ≤600 ms based on Screening ECG.
• Body weight of at least 45 kg with body mass index between 18.0 and 40.0 kg/m2, inclusively at Screening.
• Male and female participants of childbearing potential must agree to use highly effective contraception throughout the duration of the study.
• Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.
• Participants age 15 to \<18 years capable of providing signed assent.