Efficacy and Field Safety of Ilunocitinib for the Control of Allergic Dermatitis in Client-Owned Dogs: A Multicenter, Double-Masked, Randomised, Placebo-Controlled Clinical Trial.

Abstract

BACKGROUND: Inhibition of the Janus kinase pathway is an established treatment for allergic dermatitis. OBJECTIVE: To evaluate the efficacy and safety of ilunocitinib for control of pruritus in dogs with allergic dermatitis in a randomised, double-masked clinical trial. ANIMALS: Three-hundred-and-six dogs at 15 veterinary clinics. MATERIALS AND METHODS: Enrolled client-owned dogs with severe pruritus and a presumptive diagnosis of allergic dermatitis were randomised to receive either ilunocitinib (n&#x2009;=&#x2009;206; 0.6-0.8&#x2009;mg/kg) or placebo (n&#x2009;=&#x2009;100; 0&#x2009;mg/kg) once daily for 28&#x2009;days. Pruritus was assessed by owners using a pruritus Visual Analog Scale (PVAS). Treatment success was defined as &#x2265;&#x2009;50% reduction from baseline PVAS on at least five of seven initial treatment days. Clinical remission from pruritus was considered achieved when PVAS <&#x2009;2. Safety assessments were conducted over 112&#x2009;days. RESULTS: On Day (D)7, 25.4% of ilunocitinib-treated dogs achieved treatment success compared to 7.7% of placebo dogs (p&#x2009;=&#x2009;0.006). Starting on D3, the proportion of dogs with a&#x2009;&#x2265;&#x2009;50% reduction from baseline PVAS was significantly higher in the ilunocitinib group (p&#x2009;<&#x2009;0.01) and by D28, a significantly higher percentage of ilunocitinib-treated dogs (51.8%) achieved clinical remission compared to placebo dogs (12.7%; p&#x2009;<&#x2009;0.05). Signs of dermatitis improved within 7&#x2009;days. The 112-day ilunocitinib treatment was well-tolerated. CONCLUSIONS AND CLINICAL RELEVANCE: Ilunocitinib administered once a day was well tolerated and effective at rapidly reducing pruritus, with steady and continuous improvement over time. Clinical remission of pruritus was achieved by 51.8% of ilunocitinib-treated dogs by D28, regardless of allergic aetiology.