About Cystic Fibrosis and

Duchenne Muscular Dystrophy

About Cystic Fibrosis (CF)

CF is among the most common life-threatening genetic disorders worldwide. According to the Cystic Fibrosis Foundation, CF affects approximately 30,000 adults and children in the United States and, according to the European Cystic Fibrosis Foundation, it affects a similar number of patients in Europe. CF occurs in approximately one of every 3,500 live births, with approximately 1,000 new cases diagnosed each year in the United States. There is a commercially available genetic test to determine if a patient's CF is caused by a nonsense mutation and it is estimated that nonsense mutations are the cause of CF in approximately 10% of patients in the United States. There is currently no available therapy to correct defective CFTR production and function. Instead, available treatments for CF are designed to alleviate the symptoms of the disease. These treatments include chest physical therapy to clear the thick mucus from the lungs, antibiotics to treat lung infections and a mucus-thinning drug designed to reduce the number of lung infections and improve lung function. In addition, the majority of cystic fibrosis patients take pancreatic enzyme supplements to assist with food absorption in digestion. There is a significant unmet medical need for a treatment for the underlying cause of CF. More information regarding CF is available through the Cystic Fibrosis Foundation (www.cff.org).

About Duchenne Muscular Dystrophy (DMD)

DMD is the most common and one of the most severe of the nine types of muscular dystrophy. Muscular dystrophies are genetic disorders characterized by progressive muscle wasting and weakness. DMD occurs when a mutation in the dystrophin gene prevents the cell from making a functional dystrophin protein. Dystrophin is critical to the structural stability of the fibers in skeletal, diaphragm and heart muscle. The absence of normally functioning dystrophin results in muscle fragility and muscle injury when muscles are stretched during normal use. As muscle damage progresses, connective tissue and fat replace muscle fibers.

Because the dystrophin gene is located on the X chromosome, DMD is diagnosed almost exclusively in young boys. It is estimated that DMD affects approximately 12,000 boys and adolescents in the United States and a similar number of patients in Europe. DMD occurs in approximately 1 in 3,500 live male births, with approximately 20,000 new cases diagnosed each year in the United States. As with CF, genetic tests are available to determine if a patient's DMD is caused by a nonsense mutation. It is estimated that a nonsense mutation is the cause of DMD in approximately 13% of patients in the United States.

There is currently no available therapy to improve or correct dystrophin production and function. As a result, currently available treatments for DMD are palliative in nature. These treatments seek to address the symptoms through supportive care measures, such as bracing to give patients some opportunity to remain standing, joint stretching exercises to avoid contractures, tendon release surgery and eventual wheelchair use and assisted ventilation. Corticosteroids are also often prescribed to treat the symptoms of the disease but cause significant complications.

There is a significant unmet medical need for a treatment for the underlying cause of DMD. More information regarding DMD is available through the Muscular Dystrophy Association (http://www.mdausa.org), and the Parent Project Muscular Dystrophy (http://www.parentprojectmd.org).