PARIS and TARRYTOWN, N.Y., July 9, 2014 (GLOBE NEWSWIRE) -- Sanofi (EURONEXT : SAN and NYSE : SNY) and Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) today announced positive results from a Phase 2b dose-ranging study of dupilumab, an investigational therapy, in adult patients with moderate-to-severe atopic dermatitis (AD), a serious, chronic form of eczema. All doses of dupilumab met the primary endpoint of a greater improvement in Eczema Area and Severity Index (EASI) scores from baseline compared to placebo. In addition, the companies also announced that four earlier clinical studies of dupilumab in moderate-to-severe atopic dermatitis were published today in the New England Journal of Medicine (NEJM). Dupilumab is an investigational monoclonal antibody that blocks signaling of IL-4 and IL-13, two cytokines that play a key role in the pathogenesis of moderate-to-severe atopic dermatitis. " These clinical data, coupled with our mid-stage phase 2a results in asthma last year, support the growing scientific evidence that the IL4/IL-13 pathway may be a fundamental driver in allergic diseases," said George D. Yancopoulos, M.D., Ph. D., Chief Scientific Officer of Regeneron and President of Regeneron Laboratories. " Blocking IL-4/IL-13 signaling may provide an important new approach to atopic conditions, including asthma, atopic dermatitis and nasal polyposis, where we have ongoing clinical programs." In the Phase 2b trial, all five subcutaneous doses of dupilumab showed a dose-dependent improvement in the primary endpoint, the mean percent change in EASI score from baseline to week 16. The improvements in EASI score ranged from a high of 74 percent for patients in the highest dose group, who received 300 milligrams (mg) weekly, to a low of 45 percent in patients who received the lowest dose of 100 mg monthly, compared to 18 percent for patients in the placebo group (p<0.0001 for all doses). The most common adverse event in the Phase 2b study was nasopharyngitis, which was balanced across dupilumab treatment groups (18.5 to 23 percent) compared to placebo (21 percent). Injection site reactions were more frequent in the dupilumab group (5 to 9.5 percent) compared to placebo (3 percent), as was headache (12 to 15 percent) compared to placebo (8 percent).