An Open-label Extension Study To Evaluate Safety Of PF-06252616 In Boys With Duchenne Muscular Dystrophy

Inclusion Criteria:

1. Subjects with Duchenne muscular dystrophy who enrolled and completed study B5161002.

2. Signed and dated informed consent document (ICD) indicating that the subject's parent
or legal guardian/caregiver has been informed of all pertinent aspects of the study.

3. Subjects and their legal guardians/caregivers who are willing and able to comply with
scheduled visits, treatment plan, laboratory tests, and other study procedures.

4. Subject have;

1. Adequate hepatic function on screening laboratory assessments

2. GLDH less than 20 units/liter (2 x upper limit of normal [ULN])

3. Iron content estimate on the liver MRI within the normal range.

Exclusion Criteria:

1. Unwilling or unable (eg, metal implants) to undergo examination with closed MRI.

2. All male subjects who are able to father children and are sexually active and at risk
for impregnating a female partner, who are unwilling or unable to use a highly
effective method of contraception. In addition, all sexually active male subjects who
are unwilling or unable to prevent potential transfer of and exposure to drug through
semen to their partners by using a condom consistently and correctly. .

3. Subjects who are investigational site staff members directly involved in the conduct
of the study and their family members, site staff members otherwise supervised by the
Investigator, or subjects who are related to Pfizer employees directly involved in the
conduct of the study.

4. Other severe acute or chronic medical or psychiatric condition or laboratory
abnormality that may increase the risk associated with study participation.

5. Participation in other studies involving investigational drug(s), with the exception
of B5161002.

6. History of allergic or anaphylactic reaction to a therapeutic or diagnostic protein or
additives of this investigational product.