Regulatory approval status: no approved indication

“FDA Orphan Approval Status: Not FDA Approved for Orphan Indication” (opens the source at this quote in a new tab)

“The product is not authorised anywhere in the European Community.” (opens the source at this quote in a new tab)

“Orphan designation does not mean the medicine is available or authorised for use.” (opens the source at this quote in a new tab)

Indication under development: cardiomyopathy associated with Danon disease

“The study is designed to assess the efficacy and safety of a single intravenous dose of RP-A501 in treating the cardiomyopathy associated with Danon disease.” (opens the source at this quote in a new tab)

“RP-A501 is being developed for Danon disease, a rare genetic disorder characterized by thickening and weakening of the heart muscle, often resulting in heart failure, and for male patients, frequent death during adolescence or early adulthood.” (opens the source at this quote in a new tab)

Initial population the company states it will address (October 2026): males with symptomatic hypertrophic cardiomyopathy

“Rocket’s initial focus is males with symptomatic hypertrophic cardiomyopathy.” (opens the source at this quote in a new tab)

“$1B+ global peak opportunity with initial indication” (opens the source at this quote in a new tab)
“Addressable Opportunity in Danon Extends Beyond Males with HCM” (opens the source at this quote in a new tab)
“Danon Males with HCM” (opens the source at this quote in a new tab)
“Illustrative, non-risk-adjusted peak annual commercial opportunity based on internal assumptions regarding addressable populations, diagnosis, treatment eligibility, pricing, access and uptake.” (opens the source at this quote in a new tab)

Label expansions the company describes (October 2026): earlier treatment of males and treatment of females

“Danon Females with earlier-onset HCM” (opens the source at this quote in a new tab)
“Danon Males pre-HCM” (opens the source at this quote in a new tab)
“Danon Females with later-onset Cardiomyopathy” (opens the source at this quote in a new tab)
“Potential lifecycle expansions require additional clinical evidence and regulatory alignment and approval.” (opens the source at this quote in a new tab)
“Opportunities in additional patient populations would require further development and applicable regulatory approvals.” (opens the source at this quote in a new tab)

Pivotal trial population: males aged 8 years or older with left ventricular hypertrophy and preserved systolic function

“Males age ≥8 years, LAMP2 mutation, NYHA II-III, evidence of LV hypertrophy, elevated hsTnI” (opens the source at this quote in a new tab)

“RP-A501-0123 will enroll subjects ≥ 8 years of age with a pathogenic or likely pathogenic LAMP2 variant.” (opens the source at this quote in a new tab)
“Left ventricular ejection fraction (LVEF) ≥ 50%.” (opens the source at this quote in a new tab)
“New York Heart Association (NYHA) Class II to III.” (opens the source at this quote in a new tab)
“Anti-AAV9 neutralizing antibody titer >1:40.” (opens the source at this quote in a new tab)
“Prior cardiac or other organ (lung, liver, other) transplantation.” (opens the source at this quote in a new tab)

Exclusion of end-stage heart failure after the phase 1 experience

“These measures include exclusion of patients with end-stage HF, and a refined immunomodulatory regimen involving transient B- and T-cell mediated inhibition, with emphasis on preventing complement activation, while also enabling lower steroid doses and earlier steroid taper, with all immunosuppressive therapy discontinued 2-3 months following administration of RP-A501.” (opens the source at this quote in a new tab)

EMA paediatric investigation plan: condition and paediatric subset covered

“Treatment of Danon Disease” (opens the source at this quote in a new tab)
“From 3 years to less than 18 years of age.” (opens the source at this quote in a new tab)

EMA paediatric investigation plan: waiver from birth to less than 3 years of age

“the paediatric population from birth to less than 3 years;” (opens the source at this quote in a new tab)
“on the grounds that clinical studies with the specific medicinal product cannot be expected to be of significant therapeutic benefit to or fulfil a therapeutic need of the specified paediatric subset(s).” (opens the source at this quote in a new tab)

EMA paediatric investigation plan: studies planned in males aged 3 to less than 8 years and in females

“Open-label, single-arm, single dose trial to evaluate safety and efficacy of RP-A501 in male patients from 3 to less than 8 years of age with Danon disease with a pathogenic or likely pathogenic LAMP2 mutation(s) and evidence of left ventricular hypertrophy with preserved systolic function.” (opens the source at this quote in a new tab)
“Open-label, single-arm, single dose trial to evaluate safety and efficacy of RP-A501 in female patients with Danon disease with a pathogenic or likely pathogenic LAMP2 mutation(s) and evidence of left ventricular hypertrophy with preserved systolic function.” (opens the source at this quote in a new tab)

Condition named in the regulatory designations

“Orphan Designation: Treatment of Danon Disease” (opens the source at this quote in a new tab)

“Treatment of Danon disease” (opens the source at this quote in a new tab)