A two-part multicenter study: a randomized, double-blind, placebocontrolleddose- escalation safety phase (Part 1) followed by double-blind, placebocontrolled, adaptive phase (Part 2) study to evaluate the safety and efficacy of AB-1003 in adult subjec…

Inclusion Criteria:

1. Male and female subjects aged 18 and 65 years with clinical diagnosis of LGMD2I/R9 and confirmation of FKRP gene mutation.
2. Ability to ascend 4 stairs between 2.5 and 10 seconds.
3. Ability to walk/run 10 meters in < 30 seconds.
4. Able to understand and comply with all study procedures.
5. Sexually active females of childbearing potential and female and male partners of male subjects receiving AB-1003 must use a barrier method of contraception for the first 6 months after dosing.

Exclusion Criteria:

1. Significant cardiomyopathy as defined by echocardiogram (left ventricular ejection fraction <40%), evidence of conduction defect (increased PR and RR intervals, left bundle branch block and QTcF >480m/sec), NYHA Class 3 or 4 heart failure, or MRI gadolinium enhancement evidence of clinically important myocardial fibrosis.
2. Contraindication to MRI or hypersensitivity to contrast dyes, shellfish or iodine.
3. Implanted spinal rods, cardiac pacemaker or other implantation that would distort cardiac MRI images.
4. History of chronic liver disease (e.g. hepatitis, HIV, steatosis) or abnormal liver function (abnormal GGT and/or abnormal total/direct bilirubin and/or AST and ALT >2 ULN).
5. Abnormal renal function (GFR < 60 ml/min, using the MDRD equation).
6. Any life-threatening disease, including malignant neoplasms and medical history or malignant neoplasms within the past 5 years prior to screening (except basal and squamous cell skin cancer).
7. In the opinion of the investigator, a pre-existing medical condition that predisposes the subject to risks that outweighs the potential benefits.
8. Requirement for daytime ventilatory support.
9. Change in glucocorticosteroid treatment within 3 months prior to baseline visit.
10. Exposure to another investigational drug within 3 months prior to study treatment or any previous treatment with gene therapy.
11. Ongoing participation in any other therapeutic clinical trial.
12. Neutralizing antibody titer to AAV9 ≥ 1:5.
13. Female subjects who are pregnant, plan to become pregnant in the next 12 months, or breastfeeding.