A Study of Dupilumab in Small Children With an Allergic Condition of the Esophagus (Food Pipe): Eosinophilic Esophagitis

• dupilumab (Drug), also known as DUPIXENT®, REGN668, SAR231893: Administered as defined in the protocol

Primary outcomes

• Incidence of treatment-emergent Serious Adverse Events (SAEs) [Up to 24 Weeks]

Secondary outcomes

• Incidence of Treatment-Emergent Adverse Events (TEAEs) leading to permanent discontinuation of study treatment [Up to 24 Weeks]
• Incidence of treatment-emergent Adverse Event of Special Interest (AESIs) [Up to 24 Weeks]
• Incidence of TEAEs [Up to 24 Weeks]
• Proportion of patients achieving peak esophageal intraepithelial eosinophil count of ≤6 eosinophils per high power field (eos/hpf) (400×) [At Week 24]
• Proportion of patients achieving peak esophageal intraepithelial eosinophil count of <15 eos/hpf (400×) [At Week 24]
• Percent change in peak esophageal intraepithelial eosinophil count (eos/hpf) [Baseline to Week 24]
• Change in body weight for age percentile [Baseline up to Week 24]
• Concentrations of functional dupilumab in serum [Baseline up to Week 24]
• Incidence of Anti-Drug Antibody (ADA) to dupilumab [Up to Week 36]
• Titer of ADA to dupilumab [Up to Week 36]
• Incidence of Neutralizing Antibody (NAb) to dupilumab [Up to Week 36]

Sex: All, ages: 6 Months to 6 Years

Key Inclusion Criteria:

1. Pediatric patients aged ≥6 months and weighing ≥5 kg and <15 kg at screening with active EoE
2. History of symptom(s) determined by the investigator to be the result of EoE in the month prior to screening, as defined in the protocol
3. Baseline endoscopic biopsies, performed during the screening period, with a demonstration on central reading of intraepithelial eosinophilic infiltration in at least 2 of the 3 biopsied esophageal regions, as defined in the protocol

Key Exclusion Criteria:

1. Prior participation in a dupilumab clinical trial or past or current treatment with dupilumab
2. Initiation or change of a food-elimination diet regimen or re-introduction of a previously eliminated food group in the 6 weeks prior to screening. Patients on a food-elimination diet must remain on the same diet throughout the study
3. Other causes of esophageal eosinophilia or the following conditions: eosinophilic gastroenteritis, hypereosinophilic syndrome, and eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
4. Active Helicobacter pylori infection
5. History of Crohn's disease, ulcerative colitis, celiac disease, or prior esophageal surgery
6. Any esophageal stricture unable to be passed with a standard, diagnostic, upper endoscope or any critical esophageal stricture that requires dilation at screening
7. History of bleeding disorders or esophageal varices that, in the opinion of the investigator, would put the patient at undue risk for significant complications from an endoscopic procedure
8. Treatment with swallowed topical corticosteroids within 8 weeks prior to baseline standard of care endoscopy

NOTE: Other Protocol-Defined Inclusion/Exclusion Criteria Apply

• Clinical Trial Management, Study director, Regeneron Pharmaceuticals