Journal Scan: Examining the efficacy of a new drug for the treatment of atopic dermatitis

Why they did it

Oclacitinib is a Janus kinase inhibitor that decreases inflammatory mediators as well as cytokines that cause pruritus. While the drug has been approved for use in dogs with allergic dermatitis, the goal of this study was to determine if it is a safe and effective alternative for the treatment of atopic dermatitis in dogs.

What they did

Overall, 299 client-owned dogs with a diagnosis of chronic, nonseasonal atopic dermatitis were enrolled in the study. Dogs were randomized in a 1:1 ratio into one of two treatment groups: placebo or oclacitinib (0.4 to 0.6 mg/kg) given orally twice a day for the first 14 days then once a day until day 112. Clinicians and owners were unaware of the treatment group assignments. Response to therapy was based on the Owner Pruritus visual assessment scale (VAS) as well as the dermatologist’s assessment of the Canine Atopic Dermatitis Extent and Severity Index-02 (CADESI-02). “A treatment success for Owner Pruritus VAS was defined as at least a 2 cm reduction (on the 10-cm VAS) from baseline at the day of assessment; a treatment success for clinician’s CADESI-02 was defined as 50% or greater score reduction from baseline at the day of assessment (days 28, 56, 84 and 112).”

What they found

Baseline clinical signs, CADESI-02 scores, and demographics were similar between the two groups. Among dogs in the placebo group, 108/147 (73%) withdrew on or before day 16 of the study because of worsening clinical signs of atopic dermatitis compared with 13/152 (9%) of dogs treated with oclacitinib. Most of the placebo-treated dogs went on to enroll in an open-label study of the drug.

By day 28, 66% of oclacitinib-treated dogs showed improvement in the Owner Pruritus VAS compared with four in the placebo group (P

Health events associated with the drug were difficult to compare between groups given the low number of dogs in the placebo group at the end of the study. During the first 16 days, the rate of adverse events overall was low (