The purpose of this study is to see if male children with Duchenne muscular dystrophy (DMD) have changes in strength when given the drug Pentoxifylline as a rescue treatment. A total of 64 subjects are expected to participate through all other centers of the Cooperative International Neuromuscular Research Group (CINRG) worldwide.

The primary purpose of this study is to see whether the addition of pentoxifylline to a steroid regimen is effective in treating deteriorating muscle strength by comparing the muscle strength of PTX treated subjects and placebo treated subjects.

DMD is the most common and devastating type of muscular dystrophy (incidence 1 in 3500 live born males worldwide). DMD is characterized by a complete loss of dystrophin, leading to progressive muscle weakness and wasting.

No cure is currently available despite our present understanding of the disorder and the discovery and characterization of the causative gene and its protein product dystrophin in 1987. Corticosteroids (prednisone, deflazacort) may delay disease progression and until now it is the only treatment that proved to be beneficial for patients with DMD. Other alternative supplements like creatine and glutamine also delay diseased progression.

Inclusion Criteria:

• Male
• Age 7 years to 100 years
• Ability to ambulate for 10 meters. Assistive devices are allowed.
• Diagnosis of DMD confirmed by at least one the following:
• On stable dose of prednisone, prednisolone or deflazacort for at least 12 months prior to screening.
• Participants who are on stable dose of any combination of the following compounds (creatine, glutamine, coenzyme Q10, vitamin E, C or D, JUVEN, arginine, calcium) must have taken these medications for at least 2 months prior to screening. Subjects are not required to take these medications to participate in the study.
• All other herbs, supplements or green tea (other than those noted above) have been discontinued 3 months prior to screening.
• Ability to provide reproducible QMT bicep score with no more than 15% variation between scores during screening.
• Normal blood clotting ability evidenced by a platelet function assessment (PFA).

Exclusion Criteria:

• Currently enrolled in another treatment clinical trial.
• History of significant concomitant illness or significant impairment of renal or hepatic function.
• History of impairment of blood clotting ability (as evidenced by increased PT/PTT or PFA over the upper limit of normal (ULN)).
• Recent cerebral or retinal hemorrhage.
• History of bleeding diathesis or gastric ulcer.