CSU is an inflammatory skin condition, which causes sudden and debilitating hives and swelling on the skin. The CRL states that additional efficacy data are required to support an approval; it did not identify any issues with safety or manufacturing. An ongoing clinical trial (Study C) continues to enroll patients, with results expected in late 2024 that are anticipated to provide the additional efficacy data.

Regeneron and Sanofi remain committed to working with the FDA to advance the study of Dupixent for patients living with CSU who are inadequately controlled by antihistamines.

The potential use of Dupixent in CSU is currently under clinical development, and the safety and efficacy have not been fully evaluated by any regulatory authority.

CSU Clinical Trial Program

The clinical trial program, known as LIBERTY-CUPID, includes Studies A, B and C, three Phase 3 randomized, double-blind, placebo-controlled trials evaluating the efficacy and safety of Dupixent in two different patient populations with uncontrolled CSU. 

Study A evaluated Dupixent as an add-on therapy to standard-of-care H1 antihistamines compared to antihistamines alone in 138 patients with CSU aged 6 years and older who remained symptomatic despite antihistamine use and were not previously treated with omalizumab. Efficacy and safety data from Study A were the basis of the sBLA. Study B evaluated Dupixent in 108 patients with CSU aged 12 to 80 years who remained symptomatic despite standard-of-care treatment and were intolerant or incomplete responders to omalizumab, with results providing additional supporting data for the sBLA. Study C is an ongoing trial investigating Dupixent in the same population as Study A.