A total of 311 adults in PRIME and PRIME2 with prurigo nodularis were randomized to DUPIXENT or placebo. All DUPIXENT-treated participants received 300 mg Q2W after a 600 mg loading dose. At baseline, participants had an average WI-NRS score of ≥7 (on a scale of 0 to 10) and ≥20 prurigo nodularis lesions in total at screening visit and Day 1 (inclusion criteria). In addition, ≈60% of participants were on a background therapy of TCS/TCI, and 43% had a history of atopy (defined as having a medical history of atopic dermatitis, allergic rhinitis/rhinoconjunctivitis, asthma, or food allergy). No participants had moderate-to-severe atopic dermatitis at study entry or at any time 6 months prior to study entry (exclusion criteria).^1,2

The primary endpoint was the proportion of participants with improvement in WI-NRS by ≥4 points from baseline at Week 24 (60% of participants treated with DUPIXENT vs 18% with placebo in PRIME, P<0.001) and Week 12 (37% of participants treated with DUPIXENT vs 22% with placebo in PRIME2, P=0.022). Other endpoints included the proportion of participants with IGA PN-S 0 or 1 at Week 24 (the equivalent of 0 to 5 nodules; 48% of participants treated with DUPIXENT vs 18% with placebo in PRIME, P<0.001; 45% of participants treated with DUPIXENT vs 16% with placebo in PRIME2, P<0.001) and the proportion of participants who achieved both ≥4-point improvement in WI-NRS and IGA PN-S 0 or 1 at Week 24 (39% of participants treated with DUPIXENT vs 9% with placebo in PRIME, P<0.001; 32% of participants treated with DUPIXENT vs 9% with placebo in PRIME2, P<0.001).^1,2

IGA PN-S, Investigator’s Global Assessment PN-Stage; Q2W, once every 2 weeks; TCI, topical calcineurin inhibitors; TCS, topical corticosteroids; WI-NRS, Worst Itch numerical rating scale.