An Extension Study to Investigate the Long-term Safety and Tolerability of Itepekimab in Adult Participants With Inadequately Controlled Chronic Rhinosinusitis With Nasal Polyps

This is a double-blind, parallel-group, Phase 3, 2-arm study that is designed to provide additional safety information, assess the durability of treatment response, and provide additional PK and immunogenicity assessments. The primary purpose of this study is to evaluate safety and tolerability of both new or continued treatment with itepekimab 300 mg SC high dose or itepekimab 300 mg SC low dose in participants with CRSwNP having completed the intervention period of the clinical studies EFC18418 or EFC18419. A secondary purpose of this study is to provide efficacy outcomes beyond the intervention period of the parent trials EFC18418 and EFC18419. Study details include: * The study duration will be up to 72 weeks. * The intervention duration will be 52 weeks. * A follow-up period of 20 weeks will be conducted. * The number of visits will be 8 and the number of phone contacts will be 4.

NCT Number	NCT07424144
Lead Sponsor	Sanofi Collaborators: Regeneron Pharmaceuticals
Conditions	Chronic Rhinosinusitis With Nasal Polyps
Enrollment	59 participants
Start Date	2026-03-12
Primary Completion	2027-02-17 (estimated)
Study Completion	2027-02-17 (estimated)
Updated on ClinicalTrials.gov	2026-08-12