European regulators have accepted for review Regeneron and Sanofi's application to market Dupixent for the treatment of certain adults with atopic dermatitis.

The drugmakers are targeting the investigational biologic towards patients with moderate-to-severe forms of the condition who are candidates for systemic therapy.

Atopic dermatitis is a serious, chronic inflammatory skin disease characterised by widespread rash, itching and associated psychosocial comorbidities.

Dupixent (dupilumab) inhibits signaling of IL-4 and IL-13, two key cytokines required for the type 2 (including Th2) immune response, which is believed to be a major driver in the pathogenesis of the disease.

Data from the one-year Phase III LIBERTY AD CHRONOS trial showed that adding the drug to topical corticosteroids (TCS) significantly improved measures of overall disease severity compared to placebo/TCS.

After 16 weeks (the primary endpoint), 39 percent of patients who received dupilumab 300mg with TCS either weekly or every two weeks achieved clearing or near-clearing of skin lesions, compared to 12 percent of patients receiving placebo/TCS.

Sixty-four of patients who received the 300mg weekly dupilumab/TCS regimen, and 69 percent of those treated every two weeks, achieved EASI-75, a 75 percent reduction on an index measuring eczema severity, versus 23 percent in the placebo arm.

After 52 weeks (the secondary endpoint), 40 percent taking dupilumab/TCS weekly and 36 percent taking it every two weeks achieved clearing or near-clearing of skin lesions, compared to 12.5 percent of in the placebo/TCS group. On the EASI-75 score, the numbers were 64 percent, 65 percent and 22 percent, respectively.

Dupixent is also currently with regulators in the US, where it has been assigned a priority review with an action date of March 29 next year.

The firms are also studying the drug's potential in paediatric atopic dermatitis, asthma, nasal polyposis and eosinophilic esophagitis.