Clinical Research Directory

Inclusion Criteria: * Aged 18 to 90 years with a body weight of 50 to 125 kg and body mass index (BMI) between 18.5 and 40 kg/m\^2. * History of chronic pruritus for at least 6 months that is considered of unknown origin (without a clear association to another condition or medication) as assessed by the Investigator. * Chronic pruritus must affect at least 2 of the following body areas: legs, arms, or trunk. * History of inadequate control of pruritus with at least 1 antihistamine within 6 months of Screening. * Patient Global Impression of Severity (PGI-S) of pruritus of "severe" at Screening. * Use of a stable dose of topical bland emollient twice daily for at least 2 weeks immediately before Day 1 * Weekly mean of daily WI-NRS ≥7 at Day 1 * Negative pregnancy test Exclusion Criteria: * Known condition, other than dry skin, that is considered by the Investigator to be the primary cause of chronic pruritus, including: Presence of a primary dermatologic condition associated with pruritic skin lesions, regional neuropathic pruritus with the exception of peripheral small fiber neuropathy, severe renal failure, hepatobiliary disease, recent infectious dermatoses, suspected somatoform pruritus, ongoing drug-induced pruritus, malignancy or hemopathy, uncontrolled endocrine disease, * Liver function tests (bilirubin, AST, ALT, alkaline phosphatase) \>2.5 times above the upper limit of normal * Estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m² * History of malignancy within 5 years of Screening * History of severe or uncontrolled asthma * History of known primary immunodeficiency, is considered immunocompromised, or has been treated for a parasitic infection in the past 6 months. * History of attempted suicide within the past 2 years. * History of hypersensitivity (including anaphylaxis) to a biologic medication, vaccine, an immunoglobulin product (plasma-derived or recombinant, eg, monoclonal antibody), or to any of the IP excipients * Active hepatitis B virus (HBV) or hepatitis C virus (HCV) or is positive for HIV. * Active or untreated latent tuberculosis (TB) infection. * Any infection requiring treatment with oral or parenteral antibiotics, antivirals, antiparasitics, or antifungals within 2 weeks before Day 1. * History of drug or alcohol abuse within 1 year of Screening