A blinded, randomized clinical trial comparing the efficacy and safety of oclacitinib and ciclosporin for the control of atopic dermatitis in client-owned dogs

BACKGROUND: Ciclosporin is approved for the treatment of atopic dermatitis (AD) in dogs and has been shown to be safe and effective. Placebo-controlled studies suggest that oclacitinib is a safe and effective alternative therapy. HYPOTHESIS/OBJECTIVES: To evaluate the efficacy and safety of oclacitinib, in comparison to ciclosporin, for the control of AD in a blinded, randomized clinical trial, incorporating a noninferiority test at day 28. ANIMALS: A total of 226 client-owned dogs with a history of AD from eight sites were enrolled. METHODS: Enrolled animals were randomized to receive oral oclacitinib (0.4–0.6 mg/kg twice daily for 14 days, then once daily) or oral ciclosporin (3.2–6.6 mg/kg once daily) for 12 weeks. Owners assessed pruritus using an enhanced visual analog scale (VAS), and veterinarians assessed dermatitis using the Canine Atopic Dermatitis Extent and Severity Index (CADESI)-02. RESULTS: On days 1, 2, 7, 14, 28, 56 and 84, the percentage reduction from baseline for owner-assessed pruritus changed from 25.6 to 61.0% in the oclacitinib group compared with 6.5 to 61.5% in the ciclosporin group; differences were significant at all time points up to day 28. On day 56, ciclosporin-treated dogs showed a similar decrease in pruritus to oclacitinib-treated dogs. On day 14, the percentage reduction from baseline CADESI-02 was significantly greater in the oclacitinib group (58.7%) than in the ciclosporin group (43.0%). Three times as many adverse events attributed to gastrointestinal signs were reported in the ciclosporin group compared with the oclacitinib group. CONCLUSIONS AND CLINICAL IMPORTANCE: In this study of treatment for canine AD, oclacitinib had a faster onset of action and a lower frequency of gastrointestinal side effects compared with ciclosporin.