New mAb injection is launching for canine allergic and atopic dermatitis treatment

A new anti-IL-31 monoclonal antibody (mAb) treatment of canine allergic and atopic dermatitis is being launched by Elanco Animal Health in phases. Tirnovetmab (Befrena; Elanco) injection received USDA approval in December 2025.¹

Jennifer Miller, DVM, medical strategic lead of veterinary dermatology at Elanco Animal Health, explained in a dvm360 interview that monoclonal antibody therapies are at the forefront of innovation for veterinary medicine. “We've seen this on the human medicine side, and now we're adapting some of that for veterinary medicine. It's really exciting. These are highly purified, targeted therapies for a specific condition,” she said.

Nearly 2 in 3 itchy dogs experiencing worse itch during allergy season, according to Elanco.² The tirnovetmab injection launch provides a new treatment option that is designed to start controlling allergic itch within 24 hours. By neutralizing IL-31, a key cytokine involved in sending itch signals to the brain, tirnovetmab injection offers a differentiated 6 to 8 weeks dosing interval. For veterinarians and pet owners, it also aims to offer a new level of convenience and efficacy.¹

"We are seeing positive results from our Early Experience Program veterinarians who have started using Befrena in their clinics and will continue to increase supply of this new monoclonal antibody, as we scale our bioreactors with the anticipated manufacturing ramp-up," Bobby Modi, executive vice president, US pet health and global digital transformation, for Elanco, said in a news release.¹

Nearly 9 in 10 dogs in the US are "itchy dogs" according to their pet owners, having experienced symptoms of itch at any point throughout the year, according to Elanco. Data included in Elanco's recent America's Itchy Dogs Report also found that veterinarians reported itchy dog owners wait too long before bringing in their canine, which can lead to raw and infected skin as well as an irritated pet owner that wants quick relief for their animal. ²

As a part of the Befrena Early Experience Program, select veterinarians and veterinary dermatologists have already started using tirnovetmab injection in their clinics and seen initial improvements in itchy dogs. These dogs include Beaux from Austin, Texas, the first dog treated with the mAB therapy after experiencing hair loss caused by constant itch.¹

Matt Lane, DVM, MS, CCRT, at Liberty Animal Hospital in Texas, Beaux was “doing amazing” at his 3-week checkup appointment, "His owner is excited to see his hair growing back. He stopped itching within 24 hours of receiving the injection and his owner and I are extremely pleased with the results," Lane said in a news release.¹

Tom Lewis, DVM, DACVD, veterinary dermatologist and founder of Dermatology for Animals in Gilbert, Arizona, and an Elanco consultant, said tirnovetmab injection has been shown to be safe and effective through the 2 clinical trials he has seen and the Early Experience Program . "This will become a very important treatment option for many allergic dogs, and I am excited to use Befrena in my clinic," Lewis said.¹

Jason Pieper, DVM, MS, DACVD, veterinary dermatologist and tenured associate professor of dermatology at Iowa State University College of Veterinary Medicine in Ames and an Elanco consultant, said he has used tirnovetmab injection with a few patients and, although it's early, is optimistic and excited about these cases. "I've had several patients respond very well including one unique case that has failed multiple other treatments for atopic dermatitis. And so far, 2 weeks after receiving Befrena, this dog's doing quite well, it's wonderful,” Pieper said in the release.¹

References

1. Elanco launches Befrena tirnovetmab new anti-IL-31 monoclonal antibody: a breakthrough addition to the $1.3 billion US canine dermatology market. News release. Elanco. May 18, 2026. Accessed May 18, 2026. https://investor.elanco.com/press-releases/press-releases-details/2026/Elanco-Launches-Befrena-tirnovetmab-New-Anti-IL-31-Monoclonal-Antibody-a-Breakthrough-Addition-to-the-1-3-Billion-U-S--Canine-Dermatology-Market/default.aspx
2. America’s Itchy Dog Report. Elanco Animal Health. 2025. Accessed May 18, 2026. https://assets.elanco.com/0cec44ed-3eaa-0009-2029-666567e7e4de/33474a48-bac3-4fc4-b7fc-3589b88560fb/ElancoItchyDogsReportFINAL.pdf