Regeneron Pharmaceuticals, Inc. and Sanofi announced that the phase 3 LIBERTY-CUPID Study C trial for dupilumab (Dupixent) in chronic spontaneous urticaria (CSU) successfully met its primary and secondary endpoints. This study enrolled 151 participants, including children and adults with uncontrolled, biologic-naïve CSU. Patients were randomized to receive either dupilumab (n=74) or a placebo (n=77), in addition to histamine-1 (H1) antihistamines.

Results indicated that by week 24, 30% of patients treated with dupilumab achieved a complete response, compared to 18% in the placebo group. Moreover, patients receiving dupilumab experienced a significant reduction in itch, with an 8.64-point decrease versus a 6.10-point decrease in the placebo group. The reduction in urticaria activity severity, which measures both itch and hive symptoms, was also more pronounced in the dupilumab group, with a 15.86-point reduction compared to 11.21 points in the placebo group.

The incidence of treatment-emergent adverse events was equivalent between the dupilumab and placebo groups at 53%. However, adverse events such as accidental overdose, COVID-19 infection, and injection site reactions were more frequently observed in the dupilumab treatment group. These findings align with the earlier LIBERTY-CUPID Study A, which showed nearly double the reductions in itch and urticaria for dupilumab compared to standard care alone.

Dr. George Yancopoulos, board co-chair, president, and chief scientific officer at Regeneron, stated, "Patients with uncontrolled chronic spontaneous urticaria experience debilitating itch and hives that appear without warning and disrupt their lives." He emphasized the potential of Dupixent to provide relief with a nearly 50% reduction in itch and urticaria activity scores compared to placebo.

In October 2023, the US Food and Drug Administration (FDA) issued a Complete Response Letter for the supplemental Biologics License Application for dupilumab in this indication. Regeneron and Sanofi plan to submit these phase 3 data to the FDA by the end of 2024. Currently, Japan is the only country where a regulatory body has reviewed and approved dupilumab's safety and efficacy for CSU.