Historically Controlled Trial of Corticosteroids in Young Boys With Duchenne Muscular Dystrophy

Objective. Determine if twice-weekly high dose oral prednisone improves gross motor
development in infants and young boys with DMD. The investigators will perform a phase 2
historically controlled trial of oral twice-weekly prednisone (5mg/kg/dose on two consecutive
days) in infants and young boys with DMD. Here the investigators propose to study the effect
of this therapy in a multicenter trial of boys with DMD who are less than 30 months old at
the baseline visit. Each boy will be followed for one year.

Aim 1. Determine if treatment improves gross motor function in infants with DMD over a
6-12-month period as measured by the Bayley-III. The Bayley-III infant score is the primary
motor clinical endpoint of this therapeutic trial. Secondary outcomes include fine motor
function, speech and language, and social function.

Aim 2. Determine if treatment improves the Adaptive Behavior Subtest of the Bayley-III (ABS)
as scored by the infants' primary caregiver. In the study of untreated boys, the primary
caregiver noted clear deficits, predominantly related to areas relevant to gross motor
function. The ABS Aim 3. Determine if treatment improves performance on the North Star
Ambulatory Assessment (NSAA) for those boys who are ambulatory.

Aim 4. Determine if treatment with weekly corticosteroids is tolerated and is safe in boys
with DMD who are less than 30 months of age.

Objective 2. Determine if ultrasound of biceps and quadriceps using calibrated backscatter
improves in infants and young boys with DMD who are treated with oral high dose weekly
corticosteroids. Preliminary data of ultrasound imaging in infants and young boys with DMD
demonstrate progressive structural damage as measured by calibrated backscatter. The
ultrasound studies will be limited to the infants and boys who will enroll at the primary
site (Washington University) where Dr. Craig Zaidman has the equipment and expertise to
accomplish this aim.

Objective 3. Determine if caregiver burden changes with treatment of infants and young boys
with DMD. Preliminary data from questionnaires suggests the caregiver burden for the primary
caregiver of untreated infant and young boys with DMD is minimal. Assessment of this with in
this trial will allow us to discern if this changes with a therapeutic trial.

Inclusion Criteria:

1. Appropriate degree of weakness for age, creatine kinase greater than 20 times the
upper limit of normal, and genetic mutation known to be causative for Duchenne
muscular dystrophy .

2. Appropriate degree of weakness for age, creatine kinase greater than 20 times the
upper limit of normal and genetic or biopsy confirmation of Duchenne muscular
dystrophy in a primary relative (e.g. brother or maternal uncle).

3. De-identified, genetic studies will be reviewed by collaborator Kevin Flanigan, MD
prior to enrollment of subjects.

4. Age at entry: one month through 30 months.

Exclusion Criteria:

- Prior treatment with corticosteroids