Oclacitinib is a potent, safe and rapidly acting anti-itching JAK inhibitor. Oclacitinib was first approved by the US FDA in 2013 to treat eczema and allergic dermatitis in dogs, it is a first generation non-selective JAK inhibitor.
The treatment protocol is 0.4 to 0.6 mg/kg administered orally twice a day for 2 weeks, followed by a once daily administration for maintenance therapy.
There have been recent JAK inhibitors that have come on the market for humans for eczema recently.
Oclacitinib works rapidly in allergic dogs, even within hours of administration as with steroids. When changing from twice daily to once daily of oclacitinib there is a rebound in itching that was reported in every clinical trial. Using topical steroids or a short course of steroids at the onset of therapy, prevents or diminishes such a rebound. The benefit of oclacitinib in terms of decreasing skin lesions is generally noted in 1 to 2 weeks, which is slower than for itch.
The administration of it for dogs is generally considered safe, the side effects mirror those of steroids and cyclosporine. Although for humans it could be different. Because Oclacitinib is an immune suppressant dogs have developed demodicosis due to Demodex canis or papillomavirus infection. Because of this immunosuppressive effect, it is restricted for dogs older than 1 year of age, as giving it to a dog less than 1 can be dangerous as they already have more immature immune systems.
Overall the long term administration of oclacitinib to dogs might be a concern because the immunosuppressive effect could predispose to cancers. However longer studies have not shown that to be of the case yet.
We have written previously about treatment of eczema in dogs with another biologic medication, Nemolizumab for Itching and Atopic Dermatitis.
There is still much to learn about canine atopic dermatitis, nevertheless the knowledge derived from treating atopic dogs with these drugs might prove helpful to allergists with future drugs and drugs that are in the process of entering the market.