Jon D. Plant, DVM, Dipl. ACVD
If you haven’t already, you will soon be hearing a lot about APOQUEL® for the management of allergic dermatitis and atopic dermatitis in dogs at least 12 months of age. APOQUEL® is a new drug from Zoetis that controls pruritus and inflammation by inhibiting janus kinase enzymes, and is therefore known as a JAK inhibitor.
APOQUEL significantly reduces itch within 24 hours, with continued improvement during the first 7-14 days of therapy. In clinical trials, APOQUEL-treated dogs with atopic dermatitis were evaluated after 28 days by the owners and veterinarians. 66% of dogs treated with APOQUEL and 4% of dogs treated with placebo were judged to have a significant reduction of itching. Significant improvement was defined (in collaboration with the FDA) as a 2 cm reduction on a 10 cm pruritus visual analog scale (PVAS). Is this a case of what epidemiologist John Ioannidis calls “significance chasing?” Are the findings statistically significant, but clinically trivial?
The percent of dogs that achieved a “normal dog” level of itch (< 2.0 on the PVAS) has not been made available to us. This is, of course, the outcome measure than would mean the most to the owner of a pruritic dog, and the one that I am most interested in determining, even if the FDA was not.
I have had the opportunity prescribe APOQUEL to 20 dogs in the past 3 weeks, with follow-up examinations planned after 4 weeks of treatment. I’ve asked each owner to grade pruritus daily with the PVAS and am curious to see how many get into the “normal dog” range on the pruritus scale. Will APOQUEL live up to the hype? I hope so! But, I think we will all be more confident after we have some first-hand experience. APOQUEL is scheduled to be launched in January.
In my next post I’ll discuss the safety of APOQUEL and the patient monitoring that I am recommending to my clients.