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

• Safety with fewer than one grade 3 adverse events or fewer than two grade 2 adverse events [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]
  Safety will be measured based on fewer than one grade 3 adverse event or fewer than two grade 2 adverse events
  
  

• Change in Six-Minute-Walk-Test (6MWT) distance from baseline over two years [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  Efficacy would be a significant improvement in distance walked in the 6 minute walk test.
  
  

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.