27 Feb 2026
MSD Animal Health product, previously available in Europe, is only second-generation JAK inhibitor for pruritus associated with allergic dermatitis in dogs.
Vet Times
Job Title
The only second-generation Janus kinase (JAK) inhibitor treatment for allergic dermatitis-associated pruritus in dogs has been approved for use in the UK.
Numelvi from MSD Animal Health, featuring the atinvicitinib molecule, is the first and only second-generation JAK inhibitor indicated for use from six months (and 3kg).
The once-daily POM-V tablet is described as at least 10-times more selective for JAK1 than other family enzymes1, so therefore “has has very little to no effect on cytokines involved in haematopoiesis or immune function that are dependent on JAK2 or the other JAK family members”.
Numelvi is indicated for the treatment of pruritus associated with allergic dermatitis, including atopic dermatitis, as well as the clinical manifestations of atopic dermatitis in dogs
The product, which was available in the EU in the autumn, had been awaiting VMD approval for use in the Great Britain market.
Victoria Miles, companion animal director – Great Britain for MSD Animal Health, said: “Allergic dermatitis is a common condition that causes distress and discomfort for so many dogs.
“By combining targeted JAK1 selectivity with clinically proven efficacy in a once daily regimen, Numelvi helps make itch relief simple for dogs, pet owners and the veterinarians treating them.”
Specialist veterinary dermatologist Sue Paterson said: ““Treating canine allergic dermatitis means offering treatment which relieves itch and inflammation, whilst managing any unwanted side effects. We want to inhibit JAK1 to reduce itch and inflammation, while having little to no effect on other JAK family members.”
And fellow specialist Debbie Gow added: “The high selectivity for JAK1 contributes to the favourable safety profile of Numelvi.”
To mark the launch, a lunch-and-learn digital event, in partnership with The Webinar Vet, will take place on 26 March, with organisers hopeful of setting a Guinness World Record for a veterinary educational launch event.
1. Numelvi summary of product characteristics.
