Extension Study of NS-065/NCNP-01 in Boys With Duchenne Muscular Dystrophy (DMD)

This is a Phase II, multicenter, open-label, extension study of NS-065/NCNP-01 administered
intravenously once weekly for an additional 144 weeks to boys with DMD who complete Study
NS-065/NCNP-01-201. This study will evaluate the safety, tolerability, and clinical efficacy
of NS-065/NCNP-01 at dose levels of up to 80 mg/kg/week administered by weekly IV infusion
over an additional treatment period of 144 weeks.

Patients who complete the Phase II Dose-finding Study NS-065/NCNP-01-201 are eligible to
enroll.

Inclusion Criteria:

1. Completed Study NS-065/NCNP-01-201 through Week 25.

2. Willing and able to comply with scheduled visits, investigational product
administration plan, and study procedures.

3. Stable dose of glucocorticoid (GC), and is expected to remain on the stable dose for
the duration of the study.

Exclusion Criteria:

1. Serious or severe adverse event in Study NS-065/NCNP-01-201 that precludes safe use of
NS-065/NCNP-01.

2. Patient had a treatment which was made for the purpose of dystrophin or its related
protein induction after completion of Study NS-065/NCNP-01-201.

3. Patient took any other investigational drugs after completion of Study
NS-065/NCNP-01-201.

4. Patient was judged by the investigator and/or the Sponsor that it was not appropriate
to participate in the extension study for other reasons.