The European Medicines Agency therefore recommended dupilumab for use in the EU. The drug has been shown to reduce the extent and severity of atopic dermatitis in patients with moderate to severe disease, for whom available therapies are limited. Regarding safety, side effects are generally mild and manageable. Dupilumab is available as pre-filled syringes containing 300 mg of active substance in a solution for injection under the skin usually in the thigh or belly. The first dose is two injections of 300 mg in two different sites. This is followed by one injection every two weeks. The doctor will consider stopping treatment if the condition does not show any improvement after 16 weeks. Patients or their carers may inject the medicine if their doctor or nurse considers it appropriate. Patients with atopic dermatitis produce high levels of IL-4 and IL-13 which are involved in the disease. The active substance is a monoclonal antibody designed to block receptors for IL-4 and IL-13. By blocking the receptors, dupilumab prevents IL-4 and IL-13 from working and relieves the symptoms of the disease. Dupilumab was more effective than placebo at reducing the extent and severity of atopic dermatitis in 3 main studies in patients with moderate to severe disease. In the first study, which involved 740 patients, participants were given the active substance or placebo, both in combination with a topical corticosteroid (a medicine for inflammation applied to the skin). Dupilumab or placebo was used on its own in the other two studies involving a total of 1,379 patients. After 16 weeks of treatment, 39% of patients treated with dupilumab every two weeks in the first study showed clearing or almost clearing of their atopic dermatitis compared with 12% of patients on placebo. Taking the results of the other two studies together, 37% of patients treated with dupilumab every two weeks had clearing or almost clearing of their atopic dermatitis compared with 9% of patients on placebo. The most common side effects with Dupixent are injection-site reactions (such as redness, swelling and itching), conjunctivitis (red, itchy eye with sticky pus), blepharitis (inflammation of the eyelid) and cold sores.