A blinded, randomized, placebo-controlled, dose determination trial of lokivetmab (ZTS-00103289), a caninized, anti-canine IL-31 monoclonal antibody in client owned dogs with atopic dermatitis

Background Pruritus is the hallmark clinical sign of atopic dermatitis (AD) in dogs. Lokivetmab, a caninized anti‐canine IL‐31 monoclonal antibody, reduced pruritus and associated inflammatory skin lesions in a proof‐of‐concept study in dogs with AD. Hypothesis/Objectives The objective was to describe lokivetmab dose response in a randomized, double blind, placebo‐controlled trial. Animals Clinicians at 15 referral clinics enrolled 211 client owned dogs with a history of chronic AD. Methods Dogs were randomized to treatment with lokivetmab (0.125, 0.5 or 2.0 mg/kg) or placebo administered subcutaneously once on Day 0. Dog owners assessed visual analog scale (VAS) scores of pruritus on days 0, 1, 2, 3, 7, 14, 21, 28, 35, 42, 49 and 56. Clinicians assessed Canine AD Extent and Severity Index (CADESI‐03) scores on days 0, 7, 14, 28, 42 and 56. Results Treatment with lokivetmab (2 mg/kg) resulted in a greater percentage reduction from baseline in owner assessed pruritus (days 1–49) and clinician assessed CADESI‐03 scores (days 7–56) compared to placebo (P < 0.05); differences were achieved in lower dose groups but at later time points and for shorter duration for both owner assessed pruritus (0.5 mg/kg, days 2–35; 0.125 mg/kg, days 7–21) and clinician assessed CADESI‐03 scores (0.5 mg/kg and 0.125 mg/kg, Day 14). Conclusions and clinical importance Lokivetmab (0.5, 2.0 mg/kg) reduced pruritus compared to placebo for at least 1 month. Level and duration of response increased with increasing dose. Further studies are needed to better understand variability in individual responses across a broader population of dogs with AD. Résumé Contexte Le prurit est le signe clinique majeur de la dermatite atopique (AD) chez le chien. Le lokivetmab, un anticorps monoclonal anti IL‐31 canin, réduit le prurit et les lésions inflammatoires cutanées associées dans une étude POC (proof of concept) chez le chien atopique. Hypothèse/Objectifs L'objectif était de décrire la réponse dose dépendante au lokivetmab dans une étude contrôlée contre placebo, en double aveugle, randomisée. Sujets Les cliniciens de 15 cliniques de référé ont enrôlés 211 c‐chiens de propriétaires ayant des antécédents de AD chronique. Méthodes Les chiens ont été randomisés au traitement au lokivetmab (0.125, 0.5 ou 2.0 mg/kg) ou placebo administré en sous cutané une fois à jour 0. Les propriétaires ont évalués un score de prurit sur une VAS (échelle visuelle analogue à jours 0, 1, 2, 3, 7, 14, 21, 28, 35, 42,