Disease Background

Atopic dermatitis (AD), also called atopic eczema, is a chronic skin disorder that affects 10% to 20% of infants in the United States, accounts for 4% of acute-care pediatric visits, and underlies 80% of occupational dermatoses. Over 60 million people suffer from atopic dermatitis in Europe and the USA. The disease is often associated with other allergic conditions and 40-50% of atopic dermatitis patients will also develop asthma and/or rhinitis. Disease onset usually occurs in infants and can continue into adulthood, primarily affecting the face, neck, ears and torso. In older patients, the affected skin is focused mainly on the inward bend of the elbow and knee, as well as the ankle and wrist joints, hands, and upper eyelids. While the cause of the disease is still unknown, there are a number of factors contributing to its progression. Of these, a very significant contributor is the ‘Itch-Scratch Cycle’ where scratching provokes further irritation, injury and inflammation, including that induced by bacterial and viral infections. Irritants including certain chemicals as well as underlying allergies are known to be major contributing factors.

Medical Need

The significance of this disease is reflected in the market for dermatitis drugs. In 2002, the world-wide market exceeded $2 billion with a projected compound annual growth rate for the period 2002-2009 averaging more than 5%, leading to revenues in excess of $3 billion by 2009. Use of the standard therapies of topical corticosteroids and topical immune modulators while providing substantial benefit and diverse treatment options, is still hampered by negative side effect profiles and inability to use as a chronic regimen. As such there is considerable need for oral medications with safety and efficacy profiles consistent with chronic usage, in addition to a disease modifying capacity.