(Corrects first paragraph to say inflammation, not infection; Removes reference to food allergy from headline)
Oct 16 (Reuters) - Regeneron Pharmaceuticals Inc and Sanofi SA said on Monday their drug to treat inflammation in the esophagus, mainly caused by food allergies, met the main goal of a mid-stage study.
The drug, dupilumab, was statistically significant in improving the ability to swallow in adults with moderate-to-severe eosinophilic esophagitis, when compared with a placebo.
Eosinophilic esophagitis is a chronic, allergic inflammatory disease that damages the pipe that connects the throat and the stomach, and can lead to food getting stuck in the esophagus and difficulties in swallowing.
The U.S. Food and Drug Administration in late-March approved dupilumab to treat adults with moderate-to-severe eczema.
The drug is marketed under the trade name Dupixent, with a list price of $37,000 a year.
Regeneron and Sanofi are also developing dupilumab to treat severe asthma, a market where it will compete with a wave of other new biotech medicines, such as GlaxoSmithKline's Nucala.
Last month, shares of both Regeneron and Sanofi dipped after positive late-stage data in asthma patients failed to impress investors.
Regeneron was trading marginally down while Sanofi was slightly up before the bell on Monday. (Reporting by Divya Grover in Bengaluru; Editing by Martina D'Couto)