Merck Animal Health Wins Positive EU CVMP Opinion for NUMELVI (atinvicitinib) Tablets for Dogs
Merck Animal Health, a division of Merck & Co known as MSD Animal Health outside the United States and Canada today announced a significant milestone in its ongoing mission to provide innovative solutions for pets. The European Medicines Agency’s Committee for Veterinary Medicinal Products (CVMP) has issued a positive opinion for NUMELVI™ (atinvicitinib) Tablets for Dogs — a new, first-in-class treatment designed to ease pruritus and control the clinical manifestations associated with allergic dermatitis, including atopic dermatitis in dogs.
This new medication, upon eventual approval by the European Commission, is poised to become the only second-generation Janus Kinase (JAK) inhibitor in veterinary medicine with this range of indications — delivering much-needed relief to dogs suffering from persistent itch and skin disorders. The CVMP’s opinion brings us a significant step closer toward securing a novel therapeutic option for both dogs and their owners across the European Union.
An Innovation That Addresses a Huge Unmet Need in Veterinary Care
Itch, or pruritus, is one of the most frequently encountered complaints in veterinary practice — affecting more than 20 percent of dogs — and is frequently related to allergic skin disorders, including atopic dermatitis. The condition not only degrades a pet’s physical health, but it can profoundly undermine their quality of life, causing distress to both the pet and their owners. This distress can manifest in disrupted routines, poor rest, additional stress for the caregiver, and growing financial burdens stemming from repeated veterinary visits, diagnostic testing, follow-up care, and medication.
Managing these cases can be challenging for veterinary surgeons and pet owners alike. Traditionally, a range of treatments — from topical creams and shampoos to systematic medications — have been used to ease symptoms. However, many of these treatments come with side effects, limited efficacy, or poor tolerability. This leaves dogs in ongoing discomfort and their owners struggling to provide proper care and symptom control.
How NUMELVI Works to Provide Safe, Targeted, and Reliable Disease Control
NUMELVI (atinvicitinib) stands out due to its high selectivity for Janus Kinase 1 (JAK1) — a key signaling molecule involved in itch and allergy-related skin disorders — while sparing related kinases (JAK2, JAK3, and TYK2) that are more closely tied to hematopoietis (the formation of blood cells) and other essential cellular processes. This high selectivity for JAK1 minimizes interference with these additional signaling mechanisms, yielding a compelling safety profile alongside potent symptom control.
Evidence shows that NUMELVI is at least 10-fold more selective for JAK1 than for the other JAK family members, which underpins its ability to ease pruritus without causing significant side effects related to hematopoietic dysfunction or a broad dampening of the immune response.
Furthermore, NUMELVI is designed to be a convenient, once-daily, first-line treatment in dogs, delivering visible relief after their first dose — a crucial consideration for both dogs’ well-being and for their owners’ peace of mind.
Importantly, a study assessing the effects of this medication on dogs’ ability to respond to vaccines demonstrated that NUMELVI had no measurable impact on their vaccine responses — a strong indicator that it maintains the functionality of the adaptive immune system while addressing disease symptoms.
Comments from Merck Animal Health Executives
“Merck Animal Health is committed to delivering innovations for our customers — innovations that enable faster symptom control while preserving dogs’ health and well-being,” said Rick DeLuca, executive vice president and president, Merck Animal Health. “With today’s CVMP’s positive opinion for NUMELVI, we move a significant step forward in our quest to provide a novel, convenient, and well-tolerated treatment option for dogs suffering from pruritic skin disorders — something that can make a dramatic improvement in their daily lives, their relationships with their owners, and their overall happiness.”
Holger Lehmann, DVM, PhD, vice president and global head of Research and Development for Pharmaceuticals at Merck Animal Health, added, “NUMELVI not only offers a convenient, once-daily regimen for ease of administration but also comes with a strong safety profile that lets us safely treat dogs as young as six months of age. Furthermore, we’re proud to share data demonstrating that this medication does not undermine their ability to respond normally to vaccines — a key consideration for their ongoing health care.”
Next Milestone: Market Authorization in the European Union
This positive opinion from the CVMP paves the way for eventual authorization by the European Commission, which typically follows within a few months. The European Commission’s decision, expected in the third quarter of 2025, will enable Merck Animal Health to bring this new treatment option to veterinary practitioners across the European Union — strengthening their ability to ease suffering in dogs with pruritic skin disorders.
Once approved, NUMELVI will be a powerful addition to the clinician’s armamentarium, helping ease suffering for countless dogs while strengthening the human-animal bond.
This CVMP opinion marks a significant step forward in veterinary dermatology, reflecting Merck Animal Health’s ongoing investment in research and innovation for the well-being of pets. The eventual approval of NUMELVI (atinvicitinib) by the European Commission promises a new era in pruritic skin disease management — delivering peace of mind for both pet owners and veterinary care teams.
