PARIS (Reuters) – The European Commission approved Regeneron Pharmaceuticals’ and Sanofi’s key biologic treatment dupilumab for moderate-to-severe atopic dermatitis, the two companies said on Thursday.

The move comes after the U.S Food and Drug Administration (FDA) regulator had also approved the injectable antibody drug in March. The product is sold as Dupixent.

Atopic dermatitis is a chronic type of skin inflammation also known as eczema, which in severe cases causes constant, and often unbearable, itching.

A human monoclonal antibody, Dupixent is designed to specifically inhibit two key proteins which are believed to be major drivers of the disease.

Sanofi plans to submit an application to the FDA for a use of dupilumab in asthma by the end of the year and hinted recently at a possible use of the drug in nasal polyps.

Analysts on average expect Dupixent to reach annual sales of 4.7 billion euros ($5.53 billion) by 2023, according to Thomson Reuters data.

Shares of Regeneron and Sanofi slid earlier this month after late-stage trial data for dupilumab in asthma fell short of investor expectations. Analysts said the data appeared less impressive than the drug’s mid-stage data.

Investors had also expressed disappointment with the sales take-up of Dupixent when Sanofi published its second quarter-results in July, although but Sanofi expressed confidence that the drug would sell well.