Elanco Receives USDA Approval for Befrena™ (tirnovetmab), a New Anti-IL31 Monoclonal Antibody Injection Targeting Canine Allergic and Atopic Dermatitis

Rhea-AI Summary

Elanco (NYSE: ELAN) received USDA approval for Befrena (tirnovetmab), an anti‑IL31 monoclonal antibody injection for canine allergic and atopic dermatitis, recommended at a 6–8 week dosing interval. Befrena is approved for dogs of any age and is expected to launch in the first half of 2026. This marks Elanco's second dermatology approval in under 18 months and positions the product in the estimated $1.3 billion U.S. canine dermatology market. The approval complements Elanco's Zenrelia oral JAK inhibitor franchise; Zenrelia's label retains a boxed warning advising discontinuation for 28 days to 3 months around vaccination.

Positive

• Second dermatology approval in <18 months
• Dosing 6–8 weeks, longer interval than competitor lokivetmab (4–8 weeks)
• Targets $1.3B U.S. canine dermatology market
• Expected commercial launch H1 2026

Negative

• Competes directly with established lokivetmab (overlapping dosing window)
• Zenrelia label still carries boxed warning to withhold for 28 days–3 months around vaccination

Key Figures

Canine dermatology market $1.3 billion Estimated U.S. canine dermatology market size

Befrena dosing interval 6 to 8 weeks Recommended interval between Befrena treatments

Competitor interval 4 to 8 weeks Dosing interval for lokivetmab competitor

Second dermatology approval Less than 18 months Timeframe for Elanco’s two dermatology product approvals

Veterinarians treating dermatitis 98% Vets who routinely treat dogs for atopic dermatitis

Itchy dog patients 20% Share of vet patient population that are itchy dogs

Itchy dogs in U.S. 9 in 10 dogs Dogs reported by owners as having itch symptoms yearly

OTC spend before vet visit $400 Average owner spend on over-the-counter itch remedies

Market Reality Check

$22.52 Last Close

Volume Volume 2,624,876 is below the 20-day average of 5,909,785, suggesting a relatively subdued pre‑news session. low

Technical Shares at $22.76 are trading above the 200-day MA of $16.42 and sit 3.97% below the 52‑week high of $23.70.

Peers on Argus

ELAN was modestly positive pre‑news (+0.49%) while close peers showed mixed, mostly negative moves (e.g., PBH -1.83%, INDV -1.54%, ALKS -0.18%, LNTH -0.16%, VTRS +1.29%). This points to a company‑specific setup rather than a broad sector rotation.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Dec 18	Drug approval	Positive	+0.1%	FDA conditional approval of Credelio Quattro-CA1 for screwworm in dogs.
Dec 09	Investor Day	Positive	-5.8%	Three-year growth plan and restructuring with reaffirmed 2025 guidance.
Nov 26	Strategic partnership	Neutral	-0.2%	Elanco executive named board observer at Neurizon under license deal.
Nov 21	Regulatory authorization	Positive	+4.8%	FDA Emergency Use Authorization for Credelio CAT to treat screwworm in cats.
Nov 20	Investor conferences	Neutral	-1.0%	Participation in upcoming Evercore and Piper Sandler healthcare conferences.

Pattern Detected

Recent product and regulatory wins in companion animals have generally seen modestly positive or muted reactions, with one notable selloff on an otherwise growth‑oriented Investor Day update.

Recent Company History

Over the last six weeks, Elanco has highlighted a series of innovation and corporate developments. Companion‑animal approvals and authorizations—such as Credelio Quattro-CA1’s conditional FDA nod for screwworm on Dec 18, 2025 and Credelio CAT’s EUA for New World screwworm on Nov 21, 2025—supported its pet health franchise, with small to moderate positive price moves. A Dec 9, 2025 Investor Day laid out growth and cash flow targets plus a major restructuring, but the stock fell. Today’s USDA approval for Befrena fits the ongoing focus on innovation in dermatology and antibodies.

Market Pulse Summary

This announcement adds Befrena, an anti‑IL31 monoclonal antibody, to Elanco’s dermatology franchise alongside Zenrelia, giving veterinarians another targeted option for widespread canine allergic and atopic dermatitis. The product addresses a U.S. canine dermatology market estimated at $1.3 billion and is recommended at 6 to 8 weeks dosing intervals. In the context of recent approvals and a defined growth and restructuring plan, investors may monitor launch timing, adoption versus existing therapies, and contribution to innovation revenue targets.

Key Terms

monoclonal antibody medical

"a new anti-IL31 monoclonal antibody (mAb) injection targeting canine allergic..."

A monoclonal antibody is a laboratory-made protein designed to recognize and attach to a specific target in the body, such as a disease-causing substance or cell. It functions like a highly precise lock-and-key tool, helping to treat or detect illnesses. For investors, companies developing monoclonal antibodies can represent promising opportunities in the healthcare sector, especially as these treatments often address unmet medical needs.

mAb medical

"a new anti-IL31 monoclonal antibody (mAb) injection targeting canine allergic..."

A mAb (monoclonal antibody) is a lab-made protein designed to recognize and bind a specific target on cells or pathogens, like a custom-made key that fits one lock. Investors care because mAbs are often developed as therapies or diagnostic tools whose clinical trial results, regulatory approvals, production capacity, and patent status can drive significant revenue swings and affect a company’s valuation and risk profile.

anti-IL31 medical

"a new anti-IL31 monoclonal antibody (mAb) injection targeting canine allergic..."

An anti-IL31 is a drug, usually an antibody, that blocks the signaling protein interleukin‑31, which drives intense itching and related inflammation in certain skin and allergic conditions. Think of it as turning down an overactive alarm that causes persistent itch; successful blocking can meaningfully reduce symptoms. For investors, anti‑IL31 therapies matter because clinical trial results, safety profile, and regulatory approval determine market potential, pricing, and commercial adoption.

atopic dermatitis medical

"targeting canine allergic and atopic dermatitis. Importantly, Befrena..."

A chronic inflammatory skin condition, often called eczema, that causes dry, itchy, red patches and recurring flare-ups; think of it as a persistent rash that can come and go over a person’s life. It matters to investors because its chronic nature and large patient population create steady demand for treatments, influence drug development and approval decisions, affect healthcare costs and reimbursement, and can drive revenue and valuation shifts for companies working on therapies and diagnostics.

allergic dermatitis medical

"targeting canine allergic and atopic dermatitis. Importantly, Befrena..."

Allergic dermatitis is a skin reaction that happens when the immune system overreacts to a substance, causing redness, itching, blisters or dry patches where the skin touched the trigger; think of it like an unwanted alarm system that activates when exposed to certain chemicals, metals, or fragrances. For investors, it matters because rates of allergic dermatitis can affect demand for treatments, regulatory approvals, labeling and ingredient choices, product liability, workplace safety costs, and the marketability of consumer or medical products.

JAK inhibitor medical

"Zenrelia (ilunocitinib tablets), an effective, convenient, and safe once-daily oral JAK inhibitor..."

A JAK inhibitor is a type of medicine that blocks Janus kinase enzymes, which help cells send signals that drive inflammation and immune activity. By turning down that cellular “volume knob,” these drugs can reduce symptoms in autoimmune diseases and certain blood disorders. Investors watch JAK inhibitors because their effectiveness, safety profile, approval status, and patent position directly affect drug sales, market competition, and regulatory risk for companies developing or selling them.

boxed warning regulatory

"The label Boxed Warning continues to advise discontinuation of Zenrelia..."

A boxed warning is the strongest safety alert a drug regulator places on a medication’s official label to highlight life‑threatening or very serious risks, similar to a bold red flag attached to a product. For investors, it matters because this warning can reduce sales, increase regulatory scrutiny, raise liability and monitoring costs, and change market perception of the drug’s future revenue and risk profile.

modified live virus vaccines medical

"supports removal of the risk of fatal vaccine-induced disease from modified live virus vaccines..."

Modified live virus vaccines are made from viruses that have been weakened or genetically changed so they can’t cause serious illness but still teach the immune system to recognize and fight the real thing, like a rehearsal that uses a harmless actor. For investors, they matter because they can offer strong, long-lasting protection and lower dosing needs, but they also bring higher development, manufacturing, regulatory and liability risks that affect time to market and potential sales.

AI-generated analysis. Not financial advice.

• Elanco's second dermatology product approval in less than 18 months in the estimated $1.3 billion U.S. canine dermatology market
• Befrena has been shown to be effective for treatment of dogs of any age against canine atopic dermatitis and allergic dermatitis for 6 to 8 weeks of treatment, as needed
• USDA approval of Befrena reinforces Elanco's commitment to going beyond to deliver differentiated, high-quality products in every key therapeutic area, bolstering its leadership in canine dermatology and monoclonal antibodies (mAbs)
• Canine allergic and atopic dermatitis is a widespread concern amongst veterinarians, with data revealing that nearly 98% of vets say they routinely treat dogs for atopic dermatitis and that itchy dogs make up nearly 20% of their patient populationⁱ

INDIANAPOLIS, Ind., Dec. 31, 2025 /PRNewswire/ -- Elanco Animal Health Incorporated (NYSE: ELAN) today announced its latest entry into the rapidly growing canine dermatology space with the U.S. Department of Agriculture (USDA) approval of Befrena™ (tirnovetmab), a new anti-IL31 monoclonal antibody (mAb) injection targeting canine allergic and atopic dermatitis. Importantly, Befrena is recommended at a dosing interval of 6 to 8 weeks post-treatment, which stands in contrast to the 4 to 8 weeks of the current market competitor, lokivetmab.

USDA approval of Befrena further demonstrates Elanco's commitment to going beyond to deliver differentiated, high-quality products in every key therapeutic area, specifically bolstering its leadership in canine dermatology and monoclonal antibodies. Elanco continues to expect to launch Befrena in the first half of 2026.

The approval of Befrena marks Elanco's second dermatology product approved in less than 18 months, as it joins Zenrelia™ (ilunocitinib tablets), an effective, convenient, and safe once-daily oral JAK inhibitor for control of itching and inflammation associated with skin allergies in dogs at least 12 months of age. In September, Elanco announced improvements to the U.S. Zenrelia label with the Food and Drug Administration (FDA) concluding "the totality of evidence supports removal of the risk of fatal vaccine-induced disease from modified live virus vaccines from the labelingⁱⁱ."

The label Boxed Warning continues to advise discontinuation of Zenrelia for at least 28 days to 3 months prior to vaccination and withholding Zenrelia for at least 28 days after vaccination.

"The animal health sector is increasingly focused on antibody-based therapies, and today's approval is an important step forward in delivering high-impact innovation that enhances the quality of life for pets," said Dr. Ellen de Brabander, Executive Vice President of Research & Development at Elanco. "We are pleased to offer veterinarians and pet owners Befrena, which delivers long lasting relief to treat dogs with allergic itch." 

Earlier this year Elanco launched the America's Itchy Dogs Report, a first-of-its-kind report highlighting the impact itch has on dogs, their owners, and veterinarians. The report includes findings from multiple surveys of pet owners, as well as veterinarians, and reveals startling details on how badly dogs around the country are itching for relief and cost-effective, long-lasting solutions. According to the report, 9 in 10 dogs in the U.S. are "itchy dogs" according to their pet owners, having experienced symptoms of itchiness at some point in the year.ⁱⁱⁱ Pet owners typically try many at-home solutions before finally seeking veterinary care. On average, pet owners spend about $400 on over-the-counter remedies and wait six weeks before taking their pet to the veterinarian. Veterinarians say that itchy dog owners wait too long before bringing their dog, resulting in raw and infected skin and also an irritated dog owner who wants their dog to experience relief quickly.^iv Research shows that nearly 70% of veterinarians would be willing to stock another dermatology product in an effort to help more dogs find itch relief.^v

"Veterinarians need more options for itch relief so they can offer targeted therapy that focuses on mode of action to meet the unique needs of the individual patient to deliver fast, effective and valuable itch relief," said Dr. Griffin, veterinary dermatologist. "USDA approval of Befrena brings veterinarians a step closer to having another beneficial and safe treatment option. I'm excited to collaborate with Elanco and plan to offer this product in my practice when it becomes available."

You can learn more about Befrena and sign up for future news and webinars at www.befrenaforvets.com.

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, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. ©  2025 Elanco or its affiliates

ⁱ Elanco Animal Health. Data on File.
ⁱⁱ Zenrelia Supplemental FOI Summary
ⁱⁱⁱ Elanco Animal Health. Data on File.
^iv Elanco Animal Health. Data on File.
^v AVMA Pet Ownership and Demographic Sourcebook 2022 and Elanco Animal Health. Data on File.

Investor Contact: Tiffany Kanaga (765) 740-0314 tiffany.kanaga@elancoah.com
Media Contact: Season Solorio (765) 316-0233 season.solorio@elancoah.com  

View original content to download multimedia:https://www.prnewswire.com/news-releases/elanco-receives-usda-approval-for-befrena-tirnovetmab-a-new-anti-il31-monoclonal-antibody-injection-targeting-canine-allergic-and-atopic-dermatitis-302651357.html

SOURCE Elanco Animal Health

FAQ

What is Befrena (tirnovetmab) and which dogs is it approved for (ELAN)?

Befrena is an anti‑IL31 monoclonal antibody injection approved for treatment of canine allergic and atopic dermatitis in dogs of any age.

When will Elanco (ELAN) launch Befrena in the U.S.?

Elanco expects to launch Befrena in the first half of 2026.

How often is Befrena dosed compared with lokivetmab (ELAN news)?

Befrena is recommended at a 6–8 week dosing interval versus lokivetmab's reported 4–8 week interval.

How does Befrena affect Elanco's position in canine dermatology (ELAN)?

The approval is Elanco's second dermatology product in under 18 months, strengthening its leadership in canine dermatology and mAbs.

What market size does Befrena address for Elanco (ELAN)?

Befrena targets the estimated $1.3 billion U.S. canine dermatology market.

Does Zenrelia's label change affect Elanco's dermatology portfolio (ELAN)?

Zenrelia label was updated but retains a boxed warning advising to stop treatment for 28 days to 3 months around vaccination.