Treatment of moderate‐to‐severe canine atopic dermatitis with modified‐release mycophenolate (OKV‐1001): A pilot open‐label, single‐arm multicentric clinical trial

Background Mycophenolate is an immunomodulating agent successfully used for the treatment of moderate‐to‐severe atopic dermatitis (AD) in people. Mycophenolate is an effective steroid‐sparing treatment option for use in dogs with inflammatory skin diseases. Objective To evaluate whether once‐daily modified‐release mycophenolate (OKV‐1001) is safe and effective for treating moderate‐to‐severe canine AD. Animals Client‐owned atopic dogs ( n = 9) were enrolled. Materials and Methods In an open‐label multicentre pilot study, OKV‐1001 (30 mg/kg every 24 h) was given orally for ≤84 days. Concomitant tapering doses of glucocorticoids were administered up to Day (D)28. Clinicians assessed Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI‐04) on D0, D14, D28, D56 and D84. Body weight and clinical pathological parameters were measured at baseline and at the end of the study. Results Treatment with OKV‐1001 combined with glucocorticoids significantly reduced the severity of AD within two weeks in seven of nine (77.8%) dogs. The mean percentage change from baseline in the CADESI‐04 score was 29% ( p = 0.009) at D14 ( n = 9), 39% ( p = 0.008) at D28 ( n = 9) and 49% ( p = 0.03) at D56 ( n = 7) at which point glucocorticoids had been withdrawn. In two dogs the improvement in CADESI‐04 was 62% and 23% (respectively) on D84. No significant adverse events including clinical pathological findings were reported. Conclusions and Clinical Relevance Modified‐release mycophenolate (OKV‐1001) may represent a promising alternative treatment option for dogs with moderate‐to‐severe AD. The safety and efficacy profile of OKV‐1001 will need to be established in larger, placebo‐controlled clinical trials.