Sanofi, Regeneron score fast FDA review for Dupixent in eosinophilic esophagitis

Already with approvals in hand for eczema, asthma and rhinosinusitis, Dupixent has quickly become one of the most important drug in the portfolios of Sanofi and its antibody partner Regeneron.

Now Dupixent appears to be closing in on a fourth indication with the FDA’s acceptance—and priority review award—of the partners' Dupixent application to treat eosinophilic esophagitis (EoE).

Dupixent has been on a successful track since 2017 when it was granted orphan drug status for EoE. Breakthrough designation came from the FDA in September of 2020.

There is no medicine approved specifically for the disorder in the U.S., where it affects 160,000 people, including 48,000 who have failed multiple treatments.

The inflammatory disease damages the esophagus and makes swallowing difficult. The application is for those 12 and older at a 300 mg dose. The target date for a decision is August 3.

The application is supported by two phase 3 trials. Data from one were revealed in February at the American Academy of Allergy, Asthma and Immunology (AAAAI) conference. The results showed Dupixent trumped placebo in improving EoE symptoms at the 24-week mark.

In the study, which included 159 participants, 64% of those on the monoclonal antibody saw a reduction in disease symptoms compared with 41% in the control arm. Those on Dupixent also had a 23.8-point improvement on a dysphagia symptom questionnaire—which measures difficulty in swallowing—versus a 13.9-point improvement for those in the placebo group.

In addition, nearly 10 times as many patients on Dupixent hit histological disease remission at 59%, versus just 6% in the control arm.

The safety profile of Dupixent remained consistent with that seen in its other indications, with the most common side effect being injection-site reactions.

Last year, Dupixent registered sales of 5.25 billion euros ($6 billion), a 53% increase on 2020, Sanofi said in its annual report (PDF) in February. Last month, the company projected its peak sales will hit 13 billion euros or more.