Sanofi won expanded U.S. approval for its best-selling Dupixent injection to treat an allergic inflammation of the esophagus, the Food and Drug Administration said on Friday.

According to Sanofi, there are more than 160,000 patients in the United States living with eosinophilic esophagitis (EoE).

Sanofi’s regulatory filing for EoE is under review by the European Medicines Agency, the company said, adding that submissions to regulatory authorities in additional countries are planned by the end of 2022.

The chronic condition typically requires repeated treatments such as corticosterioids and diet change to ease the symptoms and Dupixent is the first treatment that targets the underlying cause.

Anti-inflammation drug Dupixent, jointly developed with Regeneron, is already approved for a range of other uses including atopic dermatitis, also known as eczema, and severe asthma.

Shares of Regeneron reversed course to close up 1% on Friday.

Sanofi said in March it expected peak annual sales of more than 13 billion euros ($13.77 billion) for the drug, up from a previous target of over 10 billion euros.

That excluded the potential use in chronic obstructive pulmonary disease (COPD), sometimes called smoker’s lung, where trial results are expected next year.

Dupixent, with 2021 sales of 5.25 billion euros, accounted for 13.9% of group revenue, by far Sanofi’s best-selling product.

Sanofi’s first-quarter adjusted earnings gained 16.2% on the blockbuster drug sales growth and a rebound in demand for prescription-free drugs.

Revenue from Dupixent jumped over 45% to 1.61 billion euros in the quarter, beating an analyst consensus, on prescriptions in dermatitis, asthma, and certain nasal infections.