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Do an About-Face on Itch

You know the look: the one that says, “I’m itchy—and I’ve had it!” It’s time to do an about-face with a new way forward.

Numelvi™ (atinvicitinib tablets) is the first and only second-generation Janus kinase (JAK) inhibitor for dogs1 that is highly selective for JAK1,1* the primary driver of itch and inflammation.2

Get Numelvi for Your Clinic

The “Buy Now” button will take you directly to Vetcove. If you do not have a Vetcove account, please contact your sales representative.

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You’re Highly Selective.
So Are We.

Discover why you’ll want to make Numelvi the first choice for itch relief for your canine allergic dermatitis patients.

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Ideal First-Line Treatment for Itch

Numelvi is a second-generation JAK inhibitor1 that offers a highly selective, effective, safe, and simple treatment for the control of pruritus associated with allergic dermatitis in dogs and puppies 6 months of age and older.

SELECTIVE

At least 10X more selective for JAK1 over the other JAK enzymes1*

RAPID ITCH RELIEF

Starts reducing itch within 2-4 hours3†

EFFECTIVE

>82% of dogs showed significant‡ improvement within 1 week4

SAFE

Numelvi is proven safe in dogs and puppies 6 months of age and older and can be used in dogs weighing at least 2 kg

SIMPLE

Easy once-daily dosing from day 1§

* Over the other JAK enzymes in in vitro assays.
† In a canine interleukin-31 (cIL-31)-induced pruritus model.
‡ A ≥2 cm reduction in owner Pruritus Visual Analog Scale.
§ Numelvi is taken at or around mealtime.

Get Numelvi for Your Clinic

The “Buy Now” button will take you directly to Vetcove. If you do not have a Vetcove account, please contact your sales representative.

icon: exportBUY NOW

The Science of Selectivity™

How It Works

  • Cytokines use JAK enzymes to stimulate immune cells.
  • JAK1 is the primary driver of itch and inflammation.2
  • First-generation JAK inhibitors target the JAKs with little to no selectivity.5,6
  • High selectivity for JAK1 minimizes interference with the beneficial immune functions of the other JAKs.2

Hear From the Experts 

Find out what veterinarians are saying about Numelvi. 

Benefits of Selectivity

“Numelvi really has the opportunity to change the game.” 

Watch to hear more from Dr Christine McKinney, DACVD, Veterinary Dermatologist, Merck Animal Health

Proven Efficacy

“Within hours of starting the meds, the dog stopped itching and had stopped itching for the first time in months.”

Watch to hear more from Dr Sam Geller, General Practitioner, USA 

Simplicity and Convenience

“The response to the drug was excellent. I would use it on my own dog.”

Watch to hear more from Dr Bob Sarsfield, General Practitioner, USA 

Compare Numelvi to the Competition

* Over the other JAK enzymes in in vitro assays.
§ Numelvi is taken at or around mealtime.
|| Inactivated rabies, multivalent modified live canine distemper virus (CDV), modified live canine adenovirus type-2 (CAV2), and modified live canine parvovirus (CPV) vaccine.
¶ Except for modified live (MLV) canine parainfluenza virus (CPI); MLV canine adenovirus-2 (CAV2) not analyzed.

Find out more about Numelvi, an exciting way forward in the management of canine allergic dermatitis.

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IMPORTANT SAFETY INFORMATION

NUMELVI is not for use in dogs less than 6 months of age or those with serious infections. NUMELVI may increase susceptibility to opportunistic infections, including demodicosis and interdigital furunculosis. Consider the risks and benefits of treatment prior to initiating NUMELVI in dogs with a history of recurrent demodicosis. NUMELVI is a JAK inhibitor. New neoplastic conditions (benign and malignant) have been reported in dogs treated with other JAK inhibitors. The effectiveness and safety of NUMELVI have not been evaluated in a field study beyond 28 days. The safe use of NUMELVI has not been evaluated in breeding, pregnant, or lactating dogs, nor in combination with glucocorticoids, cyclosporine, or other systemic immunosuppressive agents. For complete safety information, refer to the product label.

References

  1. Kowalski T, Schuette S. The second-generation Janus kinase inhibitor atinvicitinib is a potent and highly selective inhibitor of JAK1. Vet Dermatol. 2026;0:17. https://doi.org/10.1111/vde.70046
  2. Huang IH, Chung WH, Wu PC, Chen CB. JAK-STAT signaling pathway in the pathogenesis of atopic dermatitis: an updated review. Front Immunol. 2022;13:1068260. doi:10.3389/fimmu.2022.1068260
  3. Kowalski T, Prohaczik A, Locke K, et al. The second-generation Janus kinase inhibitor atinvicitinib significantly reduces pruritus 2-4 hours after dosing dogs in a canine interleukin-31 model. Vet Dermatol. 2026;0:17-18. https://doi.org/10.1111/vde.70046
  4. Data on File. Study Summary REF-12964. Merck Animal Health.
  5. Gonzales AJ, Bowman JW, Fici GJ, Zhang M, Mann DW, Mitton-Fry M. Oclacitinib (APOQUEL®) is a novel Janus kinase inhibitor with activity against cytokines involved in allergy. J Vet Pharmacol Ther. 2014;37(4):317-324. doi:10.1111/jvp.12101
  6. Zenrelia. Package insert. Elanco; 2025.
  7. Apoquel. Package insert. Zoetis Inc.; 2020.
  8. Numelvi. Product label. Merck Animal Health; 2025.
  9. Forster S, Trout CM, Despa S, Boegel A, Berger D, King S. Efficacy and field safety of ilunocitinib for the control of allergic dermatitis in client-owned dogs: a multicenter, double-masked, randomised, placebo-controlled clinical trial. Vet Dermatol. 2025;36(6):825-837. doi:10.1111/vde.70009