Elanco Launches Befrena™ (tirnovetmab), New Anti-IL-31 Monoclonal Antibody, a Breakthrough Addition to the $1.3 Billion U.S. Canine Dermatology Market
Phased launch of new anti-IL-31 monoclonal antibody is now underway, with product being used by select Early Experience Program veterinarians in clinics today
- Befrena is effective for the treatment of dogs against allergic dermatitis and canine atopic dermatitis with no age or weight restrictions, and lasts 6 to 8 weeks, compared to the 4 to 8 weeks of the current market incumbent, lokivetmab
- Starts controlling itch within 24 hours and is given as an in-clinic injection
- Select Early Experience Program veterinarians are already using Befrena in clinical practice and seeing positive outcomes
- Meet Beaux, Penelope and Zephyr, the first early experience patients to receive Befrena and follow their journeys to itch relief
- Befrena is Elanco's second monoclonal antibody to launch in the U.S. pet health market, joining Trutect™, the first and only approved therapeutic solution to treat canine parvovirus and has been shown to be effective for passive immunity
INDIANAPOLIS, May 18, 2026 /PRNewswire/ -- Elanco Animal Health Incorporated (NYSE:ELAN) today announced the phased launch of Befrena™ (tirnovetmab), a new anti-IL-31 monoclonal antibody (mAb) injection for treatment of canine allergic and atopic dermatitis. The launch comes at a key time, with a longer and more intense allergy season anticipated across the country this year.i With nearly 2 in 3 itchy dogs experiencing worse itch during allergy seasonii, Befrena expands Elanco's dermatology portfolio by offering a new treatment option that starts controlling allergic itch within 24 hours. By neutralizing IL-31, a key cytokine involved in sending itch signals to the brain, Befrena offers a differentiated 6 to 8 weeks dosing interval, providing veterinarians and pet owners with a new level of convenience and efficacy.
Benefits of Befrena:
- Offers at least 6 to 8 weeks of itch relief, in contrast to the 4 to 8 weeks of the current market incumbent, lokivetmab
- Starts controlling itch within 24 hours
- Given as an in-clinic injection administered by, or under the supervision of, a licensed veterinarian
Elanco received approval of Befrena from the U.S. Department of Agriculture (USDA) in December 2025, making it the company's second dermatology product, alongside Zenrelia™ (ilunocitinib tablets), to be approved and launched in the past two years.
Elanco is also now the only pet health company with two USDA approved mAb products – Befrena and Trutect. Trutect is the first and only approved therapeutic solution to treat canine parvovirus.
"The commercial launch of Befrena into the $1.3 billion U.S. canine dermatology marketiii is another exciting milestone in our innovation journey," said Bobby Modi, Executive Vice President, U.S. Pet Health and Global Digital Transformation. "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."
Make Best Friends Better – Meet the First Dogs Treated with Befrena
Nearly 9 in 10 dogs in the U.S. are "itchy dogs" according to their pet owners, having experienced symptoms of itch at any point throughout the yearii. Data in Elanco's America's Itchy Dogs Report also found that veterinarians say that itchy dog owners wait too long before bringing in their dog, resulting in raw and infected skin and an irritated dog owner who wants their dog to experience relief quickly.ii
As a part of the Befrena Early Experience Program, select veterinarians and veterinary dermatologists have already started using Befrena in their clinics and seen initial improvements in itchy dogs.
Beaux from Austin, TX was the first dog treated with Befrena after experiencing significant hair loss due to his constant itch.
According to Dr. Matt Lane at Liberty Animal Hospital at Beaux's 3-week checkup appointment, "Beaux is doing amazing, and 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."
Penelope and Zephyr were also treated with Befrena at Gigi's Animal Shelter in Columbus, OH. Both dogs experience seasonal allergies that impact their behavior and quality of life and after discussing with their veterinarian both owners chose Befrena to control their dogs' itch.
"We want to get these dogs relief and make sure they have the most comfortable experience as possible, and I think Befrena shows some real promise for that," said Dr. Meghan Herron, Senior Director of Behavior, Research, and Education at Gigi's.
Zephyr's owner is also a licensed veterinary technician at Gigi's and helped administer Zephyr's injection. You can follow along their journey below.
https://elanco.wistia.com/medias/5nbmg3s2hk
"I have been involved with two clinical trials and the Early Experience Program which has shown Befrena to be a highly safe and effective product," said Dr. Tom Lewis, veterinary dermatologist and founder of Dermatology for Animals, a group of veterinary dermatology clinics committed to caring for pets with allergies. "This will become a very important treatment option for many allergic dogs and I am excited to use Befrena in my clinic."*
"I've used Befrena in a few patients so far and while it's still relatively early, I'm very optimistic and excited about what's going to happen with these cases," said Dr. Jason Pieper, veterinary dermatologist and tenured associate professor of dermatology at Iowa State University College of Veterinary Medicine. "I've had several patients respond very well including one unique case that has failed multiple other treatments for atopic dermatitis. And so far, two weeks after receiving Befrena, this dog's doing quite well, it's wonderful."*
Learn more about Befrena and sign up for future news and webinars at www.befrenaforvets.com.
*Drs. Pieper and Lewis are consultants for Elanco.
ABOUT ELANCO
Elanco Animal Health Incorporated (NYSE:ELAN) is a global leader in animal health dedicated to innovating and delivering products and services to prevent and treat disease in farm animals and pets, creating value for farmers, pet owners, veterinarians, stakeholders and society as a whole. With 70 years of animal health heritage, we are committed to breaking boundaries and going beyond to help our customers improve the health of animals in their care, while also making a meaningful impact on our local and global communities. At Elanco, we are driven by our vision of Food and Companionship Enriching Life and our purpose – all to Go Beyond for Animals, Customers, Society and Our People. Learn more at www.elanco.com.
INDICATIONS
Zenrelia is a prescription medication used to control itching and inflammation associated with skin allergies for dogs over 12 months of age.
IMPORTANT SAFETY INFORMATION
Read the package insert, including the Boxed Warning, before using this drug. For full prescribing information speak with your veterinarian, call 1 888 545 5973 or visit www.elancolabels.com/us/zenrelia.
WARNING: INADEQUATE IMMUNE RESPONSE TO VACCINES. Based on results of the vaccine response study, dogs receiving Zenrelia are at risk of an inadequate immune response to vaccines. Discontinue Zenrelia for at least 28 days to 3 months prior to vaccination and withhold Zenrelia for at least 28 days after vaccination. Dogs should be up to date on vaccinations prior to starting Zenrelia. Do not use in dogs less than 12 months old or dogs with a serious infection. Dogs should be monitored for infections because Zenrelia may increase the chances of developing an infection. Neoplastic conditions (benign and malignant) were observed during clinical studies. The most common side effects were vomiting, diarrhea and tiredness. Zenrelia has not been tested in dogs used for breeding, pregnant, or lactating dogs and has not been evaluated in combination with glucocorticoids, cyclosporine, or other immune suppressive drugs.
Befrena, Zenrelia, Trutect, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. © 2026 Elanco or its affiliates
PM-US-26-0849
i Asthma and Allergy Foundation of America, (2026). 2026 Allergy Capitals. Retrieved from allergycapitals.org.
ii Elanco Animal Health. Data on File. REF-28442
iii Elanco Animal Health. Data on File. REF-29772
Investor Contact: Tiffany Kanaga (765) 740-0314 tiffany.kanaga@elancoah.com
Media Contact: Season Solorio (765) 316-0233 season.solorio@elancoah.com
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SOURCE Elanco Animal Health