The Future
of Itch Relief
Future
of Itch Relief
Ideal First-Line Treatment
Numelvi® (atinvicitinib tablets) is a second-generation Janus kinase (JAK) inhibitor.
Numelvi® provides an effective first-line treatment in dogs 6 months of age and > 2 kg in body weight and is indicated for
- pruritus associated with allergic dermatitis and atopic dermatitis
- clinical manifestations of atopic dermatitis
The first and only canine JAK inhibitor that is highly selective for JAK1.*
* Over the other JAK enzymes in in vitro assays.
The only JAK inhibitor safe for use in dogs and puppies as young as 6 months of age and 2 kg’s.
Itch relief starts within 2-4 hours.†
† In a canine interleukin-31 (cIL-31)-induced pruritus model.
Easy once-daily dosing from day 1.
The future of itch relief
offers reassuring safety for patients.
Selectivity in Action
Watch how Numelvi® selectively targets the primary driver of itch and inflammation.
The Science of Selectivity
Numelvi® is the only JAK inhibitor for dogs that is highly selective for JAK1.
Cytokines use Janus kinase (JAK) enzymes to stimulate immune cells.
JAK1 is the primary driver of itch and inflammation.
First-generation JAK inhibitors target the JAK enzymes with little to no selectivity for JAK1.2
High selectivity for JAK1 helps minimise interference with other JAK enzymes crucial for immune function and haematopoiesis.
Numelvi® is at least 10x more selective for JAK1 over the other JAKs.*
*Over the other JAK enzymes in in vitro assays.
Reassuring safety in dogs
Numelvi® has a proven safety profile for dogs & puppies as young as 6 months of age & > 2 kg’s.
High selectivity for JAK1 helps avoid adverse effects related to cytokines involved in haematopoiesis or host defense that are dependent on JAK2, JAK3 or TYK2.
Adverse events
- Most commonly diarrhoea, vomiting, lethargy and anorexia (decreased appetite).
- No clinically relevant changes in red blood cell parameters, clinical chemistry or urinalysis.3
- Serious infections, papillomas and skin masses were not reported.
Reduction of allergy mediated inflammation
- Leads to a reduction of inflammation-associated white blood cell counts (within the reference range).
Interactions
- No known interactions with routine treatment.
- Adequate serological response to vaccination.
Numelvi® is well tolerated and provides rapid relief
Itch relief starts within 2-4 hours1 †
Significant reduction in itch from the first dose3
Clinically relevant reduction in itch in > 81 % of dogs within 1 week3
Reduction of allergy-mediated inflammation
*Over the other JAK enzymes in in vitro assays. 1. 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. European Veterinary Dermatology Congress, 11-13 Sep 2025, Bilbao, Spain. [Abstract]. 3. Jirjis F, Domann V, Overbey L, et al. The second-generation Janus kinase 1 selective inhibitor atinvicitinib is a safe and effective once-daily treatment for pruritic in dogs with allergic dermatitis. European Veterinary Dermatology Congress, 11-13 September 2025, Bilbao, Spain. [Abstract/Poster]. † In a canine interleukin-31 (cIL-31)-induced pruritus model.
Hear From the Experts
Find out what veterinarians are saying about Numelvi®.
Dr. Christine McKinney, DACVD, Veterinary Dermatologist, MSD Animal Health
Dr. Sam Geller, Veterinary general practitioner, USA
Dr. Bob Sarsfield, Veterinary general practitioner, USA
Available in 4 Convenient Strengths
Most Dogs Require Just a Single Tablet or Half Tablet Daily
The average recommended dose is 1,0 mg atinvicitinib per kg body weight orally once daily at or within 30 minutes of mealtime.
See how easy it is to calculate dosages when prescribing Numelvi® to your patients.
For dogs >79 kg use a combination of whole or ½ tablets to achieve the target dose of 0,8-1,2 mg/kg.
Compare Numelvi® to first-generation JAK inhibitors
Have a question about Numelvi®?
Contact an MSD Animal Health RepresentativeSimplicity and Convenience
Simple for Veterinarians
- Proven safety profile for dogs and puppies as young as 6 months of age
- Available in a pack of 90 tablets
- Available in four pack strengths (4,8 mg, 7,2 mg, 21,6 mg & 31,6 mg)
- Does not require any special storage conditions
- Shelf life as packaged for sale is 36 months
Simple for Pet Owners
- Once-daily dosing from the start
- Consistent itch relief with consistent dosing
- Reassuring safety profile
Discover the revolutionary science behind Numelvi®.
Contact an MSD Animal Health RepresentativeReferences
- 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. European Veterinary Dermatology Congress, 11-13 Sep 2025, Bilbao, Spain. [Abstract]
- Gonzalez AJ, Bowman JW, Fici GJ, et al. J Vet Pharmacol Ther. 2014;37(4):317-324
- Jirjis F, Domann V, Overbey L, et al. The second-generation Janus kinase 1 selective inhibitor atinvicitinib is a safe and effective once-daily treatment for pruritic in dogs with allergic dermatitis. European Veterinary Dermatology Congress, 11-13 September 2025, Bilbao, Spain. [Abstract/Poster]
- Cosgrove SB, Wren JA, Cleaver DM, et al. Vet Dermatol. 2013;24(5):479-e114
[S4] NUMELVI® 4,8 mg tablets, Reg. No. 25/13/01 (Act 101/1965). Each tablet contains Atinvicitinib 4,8 mg
[S4] NUMELVI® 7,2 mg tablets, Reg. No. 25/13/02 (Act 101/1965). Each tablet contains Atinvicitinib 7,2 mg
[S4] NUMELVI® 21,6 mg tablets, Reg. No. 25/13/03 (Act 101/1965). Each tablet contains Atinvicitinib 21,6 mg
[S4] NUMELVI® 31,6 mg tablets, Reg. No. 25/13/04 (Act 101/1965). Each tablet contains Atinvicitinib 31,6 mg
Intervet South Africa (Pty) Ltd | Reg. No. 1991/006580/07
20 Spartan Road, Spartan, 1619, RSA | Private Bag X2026, Isando, 1600, RSA | Tel: +27 (0)11 923 9300 | E-mail: msdahza@msd.com | E-mail: salesordersmsd@msd.com
www.msd-animal-health.co.za | ZA-NUM-260500001
© 2026 Merck & Co., Inc., Rahway, NJ, USA and its affiliates. All rights reserved.