An experimental drug that works by blocking the immune response that causes unsightly, itchy skin patches looks promising for treating atopic dermatitis (AD), also known as eczema.

Atopic dermatitis (AD), or eczema, affects 10 percent of adults in the United States and about 25 percent of children worldwide.

AD is an inflammatory disorder in which the skin becomes covered in itchy, scaly lesions. These lesions cause cracks in the skin’s outer barrier, exposing patients to infection. AD is always accompanied by activation of the immune system.

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A new study shows that dupilumab, a type of drug called a monoclonal antibody (mAb), can reverse the immune response that causes AD skin lesions. Many of the scientists who conducted the study are employed by Regeneron Pharmaceuticals, the makers of dupilumab. The study was published in the Journal of Allergy and Clinical Immunology.

Dupilumab blocks the activity of two proteins: interleukin-4 (IL-4) and interleukin-13 (IL-13). Interleukins are immune proteins that increase the body’s ability to fight off viruses and bacteria. But these proteins can mistakenly target the body’s own tissues, causing an autoimmune reaction.

In previous studies, drugs that suppress the entire immune system have improved eczema patients’ symptoms. However, scientists were not sure exactly how these drugs work in patients with AD.

Lead study author Dr. Emma Guttman-Yassky, an associate professor of dermatology at the Icahn School of Medicine at Mount Sinai in New York, said in a press statement, “This study is the first evaluation of a treatment that targets specific immune proteins in atopic dermatitis, where mechanistic changes track closely with clinical measures of disease and relief from it.”

Guttman-Yassky and her colleagues took skin samples from people with moderate-to-severe AD. People who were treated with 150 milligrams or 300 milligrams of dupilumab over four weeks had less expression of genes that are usually over-expressed in AD. They also had greater expression of genes that are usually under-expressed in AD, compared to people who were treated with a placebo.

Most importantly, their skin cleared up.

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Guttman-Yassky’s study shows that abnormalities in the skin and the immune system in people with atopic dermatitis can be reversed by drugs that target just IL-4 and IL-13.

As a result of this new research, in November, the Food and Drug Administration (FDA) granted dupilumab a breakthrough therapy designation. This designation may speed up the FDA’s approval of the drug as a treatment for moderate-to-severe AD in adults.

Guttman-Yassky noted that it’s difficult to say how long phase III, or late stage, studies will take to complete. However, she said, “We will probably see new drugs available to treat atopic dermatitis in the next few years.”

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Current treatments for AD include topical moisturizers, creams, soaps, and steroid ointments. Sunlight and even ultraviolet light therapy may also help.

Dr. Daniel Aires, director of dermatology at the University of Kansas Hospital, gave his thumbs-up to the new study. Aires told Healthline, “The new drug appears to help normalize the atopic molecular ‘signature’… Extremely severe disease can require systemic treatment, but these often bring risk of serious side effects. Dupilumab may be an important new modality for treating these patients. Longer term studies and aftermarket evaluation will be needed to assess longer term safety issues.”

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