24 Sept 2025
MSD Animal Health says second-generation Janus kinase (JAK) inhibitor for treatment of pruritus could help ensure more dogs received a prescribed treatment in practice.
Paul Imrie
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Rob Kelly, executive vice-president for global marketing and EURAM region lead for MSD.
The company behind an innovative next-generation pruritus treatment is confident it will help boost the number of new dermatology clients to clinics.
MSD Animal Health released Numelvi, which it described as the first and only second-generation Janus kinase (JAK) inhibitor for treatment of pruritus associated with canine allergic dermatitis, on the European market in July.
Available in Northern Ireland, the company hopes for Great Britain approval in 2026.
While first-generation JAK inhibitors also targeted other enzymes, including JAK2, JAK3 and TYK-2, the company researched numerous molecules for one able to selectively target and inhibit JAK1 – the enzyme causing itching and related inflammation in dogs.
MSD scientists found the solution by developing the atinvicitinib molecule, the active agent in Numelvi, which has 10 times selectivity for JAK1 over the other enzymes, minimising disruption of immune defences and blood cell production.
At its official press launch in Vienna, where Numelvi’s European production plant is based, company scientists and representatives said not only could the once daily tablets safely and successfully treat the condition, but they could help ensure more dogs received a prescribed treatment in practice.
Rob Kelly, executive vice-president for global marketing and Europe’s lead for MSD, said the launch reflected the company’s “ongoing commitment to delivering innovative solutions that address the unique medical needs of veterinarians and their patients”.
Mr Kelly said: “As an industry, we are obliged to innovate.
“But if we innovate technology at a price point that does not give all consumers and pet owners access, that is a problem. We have really taken that into account.
“Our market research shows that there are dogs in Europe today not treated with the best technology because there is a price barrier to the consumer.
“Generally, we are positioning this to give as many patients access to the product.”
He added: “We are expecting this to be the number one used JAK product in Europe, because of all the reasons and benefits the product has in terms of selectivity and efficacy and safety, but equally because we think we are going to create a whole new market of consumers who don’t feel they have access to [JAK inhibitors] because they are priced out the market.”
Karima Yadi, director for business execution at MSD, said 80% of the estimated 11 million dogs in Europe that develop pruritus were treated at a practice, but the remainder received over-the-counter topical solutions.
She added: “This gives us an idea of the size of the problem, and the urgent need for an effective and safe therapy that breaks the cycle of itch and inflammation, and provides also a better quality of life to dogs.
“We acknowledge this market is segmented into what we call the first timers – they represent about 43% – and the ongoing patients with a history of pruritus.
“This is actually a great opportunity for these newcomers to be treated with an alternative treatment that is effective and safe, and that is meeting the key drivers of the vets behind the prescription decision.”
Austrian specialist dermatology vet Regina Wagner, who spoke at the launch, said: “Allergic dermatitis can significantly impact quality of life for both the dog and its owner due to emotional distress, interruptions in sleep and routines, increased expenses, and time lost to provide treatment and veterinary follow up.”
