Sanofi Dupixent gets USFDA Breakthrough Therapy designation to treat eosinophilic esophagitis

There are currently no FDA-approved medicines for EoE, a chronic and progressive type 2 inflammatory disease that damages the esophagus and prevents it from working properly. Over time, excessive type 2 inflammation causes scarring and narrowing of the esophagus, making it difficult to swallow. If left untreated, EoE can affect a patient's ability to eat and cause food to become stuck after being swallowed (food impaction), which can lead to a medical emergency.

In the U.S. alone, there are approximately 160,000 patients with EoE who are currently being treated with various unapproved therapies or diet modification. Of these patients, approximately 50,000 have failed multiple treatments.

Sanofi and Regeneron previously reported positive results from Part A of the pivotal Phase 3 trial evaluating Dupixent in patients 12 years and older with EoE. Part A of the randomized, double-blind, placebo-controlled trial of 81 patients met both of its co-primary endpoints, as well as all key secondary endpoints. Patients treated weekly with Dupixent 300 mg over a 24-week treatment period experienced a reduction in symptoms, esophageal inflammation and abnormal endoscopic findings in the esophagus.

Part A of the trial also demonstrated safety results consistent with the known safety profile of Dupixent in its approved indications. The EoE trial is ongoing, with additional patients enrolling in Part B as well as patients continuing in a 28-week extended active treatment period (Part C) after completing either Part A or Part B.

Breakthrough Therapy designation is designed to expedite the development and review of drugs in the U.S. that target serious or life-threatening conditions. Drugs qualifying for this designation must show preliminary clinical evidence that the drug may demonstrate a substantial improvement on clinically significant endpoints over available therapies, or over placebo if there are no available therapies.

In 2017, Dupixent also was granted Orphan Drug designation for the potential treatment of EoE. This is given to investigational medicines intended for the treatment of rare diseases that affect fewer than 200,000 people in the U.S.

The potential use of Dupixent in eosinophilic esophagitis is currently under clinical development, and its safety and efficacy for this indication have not been evaluated by any regulatory authority.