Open-label, Dose Escalation Study of Safety and Preliminary Efficacy of TN-401 in Adults with PKP2 Mutation-associated ARVC

Inclusion Criteria:

• PKP2 mutation (pathogenic or likely pathogenic)

• Arrhythmogenic Right Ventricular Cardiomyopathy as defined by the 2010 revised TaskForce Criteria

• Left Ventricular Ejection Fraction ≥50%

• Functioning Implantable Cardiac Defibrillator with remote integration capabilitiesat least 9 months prior to Screening

• NYHA Functional Class I, II, or III

• Frequent premature ventricular contractions (PVCs)

Exclusion Criteria:

• Ventricular tachycardia (VT) ablation within 6 months of Screening or planned VTablation within 6 months after Screening

• High AAV9 neutralizing antibody titer

• Prior myocardial infarction

• Right Ventricular Heart Failure

• Class IV Heart Failure

• Clinically significant renal disease

• Clinically significant liver disease