A Gene Therapy Study of RP-A501 in Male Patients With Danon Disease

The study is a single arm Phase 2 clinical trial to characterize the safety and efficacy of RP-A501, a recombinant adeno-associated serotype 9 (rAAV9 capsid containing the human lysosome-associated membrane protein 2 isoform B (LAMP2B) transgene) in male patients with Danon Disease.

Male subjects ≥8 years of age will receive a single intravenous infusion of RP-A501.

Key Inclusion Criteria:

• Documentation of a pathogenic or likely pathogenic variant of the LAMP2 gene.
• Male.
• Age ≥8 years.
• Evidence of left ventricular hypertrophy with preserved systolic function phenotype as defined by each of the following:

• Abnormal thickening of Left ventricular wall,
• Left ventricular ejection fraction (LVEF) ≥ 50%.
• New York Heart Association (NYHA) Class II to III.
• High sensitivity Troponin I (hsTnI) ≥20% above the upper limit of normal (ULN)
• Ability to comply with study procedures including investigational therapy and follow-up evaluations.

Key Exclusion Criteria:

• Anti-AAV9 neutralizing antibody titer >1:40.
• Severe heart failure or requirement for advanced therapies.
• History of intracardiac thrombosis or arterial thromboembolic events including stroke, transient ischemic attack (TIA), acute coronary syndrome, myocardial infarction or unstable angina.
• Prior cardiac or other organ (lung, liver, other) transplantation.