Itch reduction (as measured by the proportion of patients with a ≥4-point improvement in WI-NRS) was the primary endpoint in two 24-week randomized, double-blind, placebo-controlled, multicenter, parallel-group studies (PRIME and PRIME2). In the PRIME trial, a nominal difference was observed at Week 4 (19% with DUPIXENT vs 4% with placebo; P=0.0066), with significant improvement at Week 24.1,2

Definitive conclusions cannot be made for results earlier than at 24 weeks in PRIME. Data were not multiplicity controlled.


  • 37% of DUPIXENT patients achieved a meaningful response at Week 12 vs 22% with placebo; P=0.0216 [primary endpoint]. At Week 24, 58% of DUPIXENT patients achieved significant itch relief vs 20% with placebo; P<0.0001 [secondary endpoint]1,2