A Gene Therapy Study for Homozygous Familial Hypercholesterolemia (HoFH)

Study Overview
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Brief Summary
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This first-in-human study is intended to evaluate the safety and preliminary effectiveness of AAV (Adeno-associated virus)-based liver-directed gene therapy in the treatment of adults with Homozygous Familial Hypercholesterolemia (HoFH).

Detailed Description
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Homozygous Familial Hypercholesterolemia (HoFH) is a rare genetic metabolic disorder characterized by absent or severely reduced capacity to catabolize circulating LDL (Low density lipoprotein) particles by the hepatic LDL receptor. As a consequence, HoFH subjects present abnormal total plasma cholesterol (LDL-C) levels, resulting in severe atherosclerosis often leading to early onset of cardiovascular disease. Early initiation of aggressive treatment for these patients is therefore essential. Unfortunately, despite existing therapies, treated LDL-C (Low density lipoprotein cholesterol) levels could remain well above acceptable levels. Thus, the functional replacement of the defective LDLR via AAV-based liver-directed gene therapy may be a viable approach to treat this disease and improve response to current lipid-lowering treatments. This first-in-human study is intended to evaluate the safety of this gene therapy investigational product and assess preliminary evidence of efficacy using plasma LDL-C levels as a surrogate biomarker for human LDLR transgene expression. Subjects may be asked to participate in an optional kinetics study to assess the metabolic mechanism by which LDL-C is reduced.

Official Title
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AAV8-mediated Low Density Lipoprotein Receptor (LDLR) Gene Replacement in Subjects With Homozygous Familial Hypercholesterolemia (HoFH)

Conditions
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Homozygous Familial Hypercholesterolemia (HoFH)

Intervention / Treatment
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* Genetic: AAV directed hLDLR gene therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female ≥ 18 years of age. Untreated and/or treated LDL-C levels and clinical presentation consistent with the diagnosis of homozygous FH (Familial hypercholesterolemia) Molecularly defined LDLR mutations at both LDLR alleles. A baseline serum AAV8 NAb (Neutralizing antibody) titer ≤ 1:10. Exclusion Criteria Unwilling to wash out of the following lipid lowering therapies for the pre-specified time period: niacin > 250 mg/day: within 6 weeks of baseline fibrates: within 4 weeks of baseline lomitapide: within 8 weeks of baseline mipomersen: within 24 weeks of baseline History of cirrhosis or chronic liver disease based on documented histological evaluation or non-invasive imaging or testing. Abnormal liver function tests (LFTs) at screening (AST (Aspartate aminotransferase) or ALT (Alanine aminotransferase) > 2 × upper limit of normal (ULN) and/or Total Bilirubin of > 1.5 × ULN

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: dose escalation
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1<br>2.5E12 (genome copies)/kg (kilogram) body weight (E means the exponential constant) | Genetic: AAV directed hLDLR gene therapy<br>* AAV directed hLDLR gene therapy is a novel adeno-associated viral (AAV8) vector with human low-density lipoprotein receptor (hLDLR) gene<br>|
| Experimental: Cohort 2<br>7.5E12 GC/kg body weight | Genetic: AAV directed hLDLR gene therapy<br>* AAV directed hLDLR gene therapy is a novel adeno-associated viral (AAV8) vector with human low-density lipoprotein receptor (hLDLR) gene<br>|
| Experimental: Cohort 2 Expansion<br>7.5E12 GC/kg body weight DSMB (Data Safety Monitoring Board) approved expansion of Dose 2 cohort, 3 additional subjects enrolled and received prophylactic corticosteroids | Genetic: AAV directed hLDLR gene therapy<br>* AAV directed hLDLR gene therapy is a novel adeno-associated viral (AAV8) vector with human low-density lipoprotein receptor (hLDLR) gene<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With IP (Investigational Product) Related Adverse Events | Physical examinations; Clinical laboratory parameters; and adverse event reporting | Up to 24 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent Change in LDL-C | Percent change in LDL-C compared to baseline | 18 weeks, 12 weeks for cohort 1 only, compared to baseline | 
| Percent Change in Lipid Parameters Compared to Baseline Values | total cholesterol (TC); non-high density lipoprotein cholesterol (non-HDL-C); HDL-C; fasting triglycerides (TG); overflow density lipoprotein cholesterol (VLDL-C); lipoprotein(a) (Lp(a)); apolipoprotein B (apoB) and apolipoprotein A-I (apo A-I) | 18 weeks, 12 weeks for cohort 1 only, compared to baseline | 
| Number of Participants With IP Related Adverse Events | Physical examinations; Clinical laboratory parameters; and adverse event reporting | up to 104 weeks | 
| Amount of Vector Shedding, Urine | Amount of virus secreted in urine | up to 104 weeks | 
| Amount of Vector Shedding, Plasma | Amount of virus secreted in plasma | up to 104 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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LDL Receptors, Gene therapy, Metabolic Diseases, Rare diseases, Genetic Diseases, Atherosclerosis, cardiovascular disease