Gene Transfer Clinical Trial for LGMD2D (Alpha-sarcoglycan Deficiency) Using scAAVrh74.tMCK.hSGCA

The proposed clinical trial is a dose escalation study of self-complementary
scAAVrh74.tMCK.hSGCA to LGMD2D (alpha-sarcoglycan deficient) subjects delivered via a major
lower limb artery of each leg sequentially by isolated limb perfusion (ILP). Three cohorts
(Cohorts 1A, 1B, and 2) will undergo gene transfer in a dose escalation scheme to establish
maximum tolerated dose (MTD) using toxicity. Two (n=2) adult wheelchair-dependent patients
will be enrolled in Cohort 1A and three (n =3) ambulatory subjects will be enrolled in Cohort
1B. Three (n =3) ambulatory subjects will be enrolled in Cohort 2. The first cohort (1A) will
receive a dose of 1E12 vg/kg in a single limb with delivery to the whole limb. This same dose
will be delivered to both limbs in Cohort 1B. Cohort 2 will receive a total dose escalation
of 3E12vg/kg per limb delivered to both extremities. The vector will be infused into an
indwelling catheter in the femoral artery. This will be a one-time vector infusion to an
isolated limb with a 10-minute dwell time. The total vector genome dose for each subject will
be adjusted by rounding down to the closest 10 kg.

Safety monitoring during infusion will include: activated clotting times, limb gases, real
time monitoring of arterial and venous access pressures, and perfusate temperature. Safety
endpoints will be assessed by changes in hematology, serum chemistry, urinalysis, immunologic
response to rAAVrh74 and hSGCA, and reported history and observations of symptoms. Efficacy
will be measured by the six minute walk test as well as direct muscle testing for strength
(MVICT) of lower limb muscles. These quantitative measures will be done at baseline, day 30,
60, 90, 180, and at the end of 1st and 2nd years. Subjects will be evaluated at baseline,
infusion visit (days 0-2), and return for follow up visits on days 7, 14, 30, 60, 90, and
180. On Day 180, subjects will undergo a muscle biopsy on the injected muscles in one leg to
compare with the pre-treatment biopsy done at baseline screening in the opposite leg to
establish the size of muscle fibers and any potential toxicity from gene transfer.

Inclusion Criteria

- Subjects age 7 or older; cohort 1A must be adult and wheelchair-dependent

- Proven alpha-sarcoglycan deficiency by muscle biopsy or DNA testing.

- Onset of weakness by 5 years age based on history of difficulty running, jumping and
climbing stairs.

- Subject enrolled in Cohort 1A must be adult and wheelchair dependent

- Subjects enrolled in Cohorts 1B or 2 must be able to walk independently, but must
exhibit signs of lower extremity weakness (i.e. a Gowers' sign, use a handrail for
climbing stairs) and walk ≤ 80% of predicted distance on the 6MWT based on normative
data.

- Males and females of any ethnic group will be eligible

- Ability to cooperate with muscle testing.

- Willingness of sexually active subjects with reproductive capacity to practice
reliable method of contraception (If appropriate), during the first six months after
gene therapy (females) or until two negative sperm samples are obtained post gene
transfer (males).

Exclusion Criteria

- Active viral infection based on clinical observations.

- The presence of SGCA mutations without weakness or loss of function

- Symptoms or signs of cardiomyopathy, including:

- Dyspnea on exertion, pedal edema, shortness of breath upon lying flat, or rales
at the base of the lungs

- Echocardiogram with ejection fraction below 40%

- Serological evidence of HIV infection, or Hepatitis A, B or C infection

- Diagnosis of (or ongoing treatment for) an autoimmune disease

- Abnormal laboratory values considered clinically significant (GGT > 3XULN, bilirubin ≥
3.0 mg/dL , creatinine ≥ 1.8 mg/dL, Hgb < 8 or > 18 g/Dl; WBC > 15,000 per cmm)

- Concomitant illness or requirement for chronic drug treatment that in the opinion of
the PI creates unnecessary risks for gene transfer

- Pregnancy

- Subjects with AAVrh74 or AAV8 binding antibody titers ≥ 1:50 as determined by ELISA
immunoassay