The main objective of the study is to assess efficacy and safety of dupilumab given up to 24 weeks in adults with CPUO.
This is a master protocol which includes 2 parallel-treatment, double-blind, 2- arm Phase 3 staggered studies of similar design (Study A and Study B) in male and female participants aged 18 to 90 years with CPUO. Study B design was to be adapted based on the results of Study A.
For both Study A and B, after an up-to-4-week screening period, participants with severe pruritus (worst-itch numerical rating scale \[WI-NRS ≥7) will enter a 4-week run-in period and will be treated with a non-sedative antihistamine and an emollient (moisturizer). Participants with severe pruritus (WI-NRS ≥7) at baseline will be randomized (1:1) to be treated for 24 weeks with either dupilumab or matching placebo in addition to their non-sedative antihistamine and emollient regimen. The treatment period for both study A and B will be followed by a 12-week follow-up period.
Participant must be 18 (or the legal age of consent in the jurisdiction in which the study is taking place) to 90 years of age inclusive, at the time of signing the informed consent.
Participants with chronic pruritus for at least 6 months before the screening visit.
Chronic pruritus considered of unknown origin as assessed by the investigator at baseline (excluding chronic pruritus secondary to dermatological or systemic conditions, of neuropathic or psychogenic origin or secondary to drugs).
Chronic pruritus must affect at least 2 of the following body areas: legs, arms, or trunk.
Severe concomitant illness(es) that, in the Investigator's judgment, would adversely affect the patient's participation in the study.
Patients with active tuberculosis or non-tuberculous mycobacterial infection, or a history of incompletely treated tuberculosis, unless it is well documented by a specialist that the participant has been adequately treated and can now start treatment with a biologic agent.
Diagnosed with, suspected of, or at high risk of endoparasitic infection, and/or use of antiparasitic drug within 2 weeks before the screening visit.
HIV infection.