Regeneron Pharmaceuticals, Inc and Sanofi has announced positive results from it's Phase 3 trial of Dupixent® (dupilumab) in children with eosinophilic oesophagitis (EoE) aged 1-11.

In May 2022, the US FDA approved dupilimab as the first treatment for people aged 12 and older with EoE. However, there are currently no approved treatments for those under 12.


The Phase 3 randomised double-blind placebo-controlled trial investigated the efficacy of Dupixent in 102 children aged 1 to 11 with EoE. 37 received a higher dose of the drug (based on body weight), 31 received a lower dose and 34 received a placebo.

The primary endpoint after the 16-week treatment period was histological disease remission (peak oesophageal intraepithelial eosinophil count of ≤6 eosinophils / high power field).


At 16 weeks, 68% of the participants on higher dose and 58% on lower dose achieved the primary endpoint, compared with 3% on placebo (p<0.0001).

The children on higher dose also experienced:

  • 86% reduction in peak oesophageal intraepithelial eosinophil count from baseline compared to a 21% increase for placebo (p<0.0001)
  • 0.88 and 0.84 reduction from baseline in disease severity and extent compared to 0.02 and 0.05 increase for placebo (p<0.0001)
  • 3.5-point reduction in abnormal endoscopic findings from baseline compared to a 0.3-point increase for placebo (p<0.0001)
  • 3.09 percentile increase in body weight for age percentile from baseline compared to 0.29 for placebo

Histological, anatomic and cellular secondary endpoints were also analysed for the lower dose group, with all being nominally significant and generally comparable with the higher dose.

Safety results were generally consistent with the known safety profile of Dupixent in its approved EoE indication for children and adults aged 12 years and older who weigh at least 40 kg.

The trial is ongoing with a 36-week extended active treatment period to evaluate long-term outcomes.

Dupixent is the first medicine to alleviate key signs of eosinophilic esophagitis in children as young as 1 year of age in a Phase 3 trial. The efficacy of Dupixent demonstrates that in this age group, as in adults, IL-4 and IL-13 are key drivers of the type 2 inflammation underlying this debilitating disease.

- George D. Yancopoulos, M.D., Ph.D., President and Chief Scientific Officer at Regeneron