An observational study in Danon Disease, sponsored by Rocket Pharmaceuticals Inc.. Recruiting at 16 sites in 7 countries. Open to participants aged 8 Years and older. Per ClinicalTrials.gov, last updated 2026-10-19.
Sponsored by Rocket Pharmaceuticals Inc. · Observational
The goal of this international observational study is to learn about the natural history of Danon disease in male patients (≥8 years of age) and female patients (8 to 50 years of age).
This is an international observational study with both retrospective and prospective data collection. The study is designed to describe the natural history of Danon disease, a rare X-linked genetic disorder, and one of the most severe and penetrant forms of inherited cardiomyopathy. This study will collect data about the clinical course of Danon disease, including signs and symptoms, key clinical events, and the impact of the disease on quality of life as managed with the current standard of care. A hybrid (retrospective and prospective data collection) approach is being used to generate robust and longitudinal data. A subset of patients will be used as an External Control Arm for comparison to RP-A501 Trial participants.
553 studies on the registry are indexed under Cardiomyopathies; 152 are open to participants now.
This study's planned enrollment of 60 is below the median of 200 across 263 observational studies indexed under Cardiomyopathies.
Browse Cardiomyopathies studies →Rocket Pharmaceuticals Inc. is the lead sponsor of 19 studies on the registry; 7 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Male patients 8 years of age and over, Female patients 8 to 50 years of age (at the point of enrollment) with confirmed Danon disease recruited from a range of applicable care settings.
Prospective Cohort:
Age ≥ 8 years at enrollment
Female Prospective Cohort:
Evidence of left ventricular hypertrophy in the 12 months prior to or at enrollment.
Retrospective (only) Cohort:
At least 30 days of retrospective medical records available prior to cardiac transplantation or mechanical circulatory support
Female Retrospective (only) Cohort:
Key Exclusion Criteria:
All Cohorts:
Previous treatment with a gene therapy
Prospective Cohort:
Prior cardiac transplantation at time of enrollment to this study
Female patients:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Other: No intervention
Other: No intervention
No intervention
Left Ventricular Mass Index (LVMI) by echocardiogram
Evaluation of change over duration of follow up
Time frame: Month 12, 24, 36
Cardiac biomarkers (hsTnI)
Evaluation of change over duration of follow up
Time frame: Month 12, 24, 36 (when available)
Cardiac biomarkers (NT-proBNP, BNP)
Evaluation of change over duration of follow up
Time frame: Month 12, 24, 36 (when available)
NYHA class
Evaluation of change over duration of follow up
Time frame: Month 12, 24, 36
KCCQ-12
Evaluation of change over duration of follow up
Time frame: Month 12, 24, 36
PedsQL
Evaluation of change over duration of follow up
Time frame: Month 12, 24, 36
Event free survival with events defined as death, heart transplant, mechanical circulatory support (MCS) or heart failure hospitalization
Evaluation over duration of follow up
Time frame: Month 12, 24, 36
Six Minute Walk Test
This test measures the distance that a subject can quickly walk on a flat, hard surface in a period of 6 minutes.
Time frame: Month 12, 24, 36
CBC
CBC with differential
Time frame: At enrollment
Serum Chemistry
Electrolytes
Time frame: At enrollment
ECG
Twelve-lead ECGs are relevant to describe changes in cardiac rhythm that may further contextualize the clinical events/endpointsevents/endpoints
Time frame: Month 12, 24, 36
Serum chemistry
Creatinine
Time frame: At enrollment
Serum chemistry
LDH
Time frame: At enrollment
Serum chemistry
BUN
Time frame: At enrollment
Serum chemistry
eGFR
Time frame: At enrollment
Serum chemistry
LFT
Time frame: At enrollment
Anti-AAV9 titer
Change in antibody assay findings over time
Time frame: Month 12, 24, 36
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Rocket Pharmaceuticals Inc.