Befrena (tirnovetmab) is a new USDA-approved injection for dogs with allergic and atopic dermatitis, approved December 31, 2025 by Elanco Animal Health. It works by blocking interleukin-31, the cytokine that sends itch signals to the brain, and is designed to start controlling itch within 24 hours. It is given in-clinic every 6 to 8 weeks. It targets the same itch pathway as the existing Cytopoint injection but with a potentially longer dosing interval. Ask your vet whether it is right for your dog at your next appointment.
If your dog is one of the many spending summer chewing their paws, rubbing their face on the carpet, and keeping you both awake scratching, there is a new treatment option that launched in 2026 worth knowing about. Befrena is a monoclonal antibody injection that targets the itch signal at its source, and it represents a genuine addition to the toolkit for managing allergic dogs, not just a rebranded version of something already available.
What Is Befrena?
Befrena is the brand name for tirnovetmab, a monoclonal antibody injection developed by Elanco Animal Health and approved by the US Department of Agriculture (USDA) on December 31, 2025. It is indicated for the treatment of allergic dermatitis and canine atopic dermatitis in dogs.
Monoclonal antibodies are highly specific proteins engineered to bind to a single molecular target. In veterinary medicine, this class of therapy has been growing steadily, largely because it avoids the broad immune suppression that comes with long-term corticosteroid use. Befrena joins Cytopoint (lokivetmab), also a monoclonal antibody, as an injectable option in this category. It is Elanco's second USDA-approved monoclonal antibody product, joining Trutect, their treatment for canine parvovirus.
The canine dermatology market is significant. DVM360 reports that nearly 98% of veterinarians say they routinely treat dogs for atopic dermatitis, and itchy dogs make up close to 20% of veterinary patient visits. This is a condition that affects a lot of dogs and causes real day-to-day suffering for both pets and their owners.
How It Works: The IL-31 Pathway
To understand what Befrena does, it helps to understand what makes an allergic dog itch in the first place. When an allergic dog encounters a trigger, whether pollen, dust mites, or a dietary protein, the immune system releases cytokines. One specific cytokine, interleukin-31 (IL-31), binds to receptors in sensory nerve cells and transmits an itch signal directly to the brain. That signal is what produces the compulsive scratching, chewing, and rubbing that you see.
Befrena is an anti-IL-31 monoclonal antibody. It circulates in the bloodstream and binds to IL-31 before it can reach those nerve receptors, effectively neutralizing the itch signal. This is targeted action at the precise biological step that produces pruritus (the clinical term for itch), rather than broad suppression of the entire immune response.
Jennifer Miller, DVM, medical strategic lead of veterinary dermatology at Elanco, described the approach in an interview with DVM360: "We have seen this on the human medicine side, and now we are adapting some of that for veterinary medicine. These are highly purified, targeted therapies for a specific condition." The parallel to human biologics for conditions like psoriasis and eczema is intentional. The same scientific principles that produced drugs like dupilumab for human atopic dermatitis are being applied to veterinary medicine, though the specific molecules and targets are different.
USDA Approval and Launch
The USDA granted approval for Befrena on December 31, 2025. Elanco began a phased commercial launch in May 2026. As of the time of writing, the product is being introduced through select veterinary practices in an Early Experience Program before broader rollout.
According to Elanco's launch announcement, early experience veterinarians are already using Befrena in clinical practice and reporting positive patient outcomes. The product targets the $1.3 billion US canine dermatology market. Pricing has not been publicly listed and will vary by practice and geographic area.
Befrena is given as an in-clinic injection administered by or under the supervision of a licensed veterinarian. It is not available for home administration. This is consistent with how other veterinary monoclonal antibodies, including Cytopoint, are handled.
Befrena vs Cytopoint: What Is Different
The most common question veterinarians are already fielding is how Befrena differs from Cytopoint (lokivetmab), the existing anti-IL-31 injectable from Zoetis that has been on the market since 2016. Both are monoclonal antibodies targeting the IL-31 pathway. So what makes them different?
| Feature | Befrena (tirnovetmab) | Cytopoint (lokivetmab) |
|---|---|---|
| Manufacturer | Elanco Animal Health | Zoetis |
| Target | Interleukin-31 (IL-31) | Interleukin-31 (IL-31) |
| Approved | December 2025 (USDA) | 2016 (USDA) |
| Dosing interval | Every 6 to 8 weeks | Every 4 to 8 weeks |
| Administration | In-clinic injection by veterinarian | In-clinic injection by veterinarian |
| Age/weight restrictions | None stated | None stated |
| Onset of action | Within 24 hours (per Elanco) | Within 24 hours (per Zoetis) |
The key practical difference is the dosing interval. Befrena is recommended every 6 to 8 weeks, while Cytopoint's labeling allows for 4 to 8 weeks. For dogs whose allergy symptoms break through at the lower end of that range, the Befrena interval could be an advantage if clinical duration holds up in real-world practice. For dogs who do well on Cytopoint every 6 to 8 weeks already, the difference in practice may be minimal.
Because Befrena is new, long-term real-world data on duration of effect across different dog populations is still accumulating. Head-to-head comparison trials between the two products are not yet publicly available as of this writing. Your veterinary dermatologist is the best person to advise whether switching makes sense for your dog based on their specific allergy pattern and response history.
Which Dogs Are Candidates
Befrena is approved for dogs with allergic dermatitis and atopic dermatitis. There are no age or weight restrictions in the USDA approval, which makes it available across the full range of canine patients, from puppies to seniors, and from Chihuahuas to Great Danes.
The dogs most likely to benefit are those whose primary complaint is pruritus associated with environmental or allergic triggers. Atopic dermatitis, which is driven by an immune response to inhaled or contact environmental allergens such as pollen, dust mites, and mold spores, is the main target indication. Dogs with flea allergy dermatitis, food allergies, or contact allergies may also experience relief if itch is the primary symptom, though addressing the underlying trigger remains important alongside any symptomatic treatment.
Dogs who have had a good response to Cytopoint but experience shorter-than-ideal duration before symptoms return may be worth discussing with their vet as potential Befrena candidates, to see whether the slightly extended dosing interval provides better coverage. Dogs who have never tried an injectable anti-IL-31 treatment are straightforward candidates for either option.
Where This Fits in the Broader Allergy Treatment Picture
It is worth being clear about what Befrena does and does not do. Like all symptomatic itch-control treatments, it manages the itch signal, but it does not address the underlying allergic disease or desensitize the immune system to its triggers. A dog given Befrena is not being cured of atopic dermatitis. They are experiencing relief from the itch while the underlying immune dysfunction continues.
Allergen-specific immunotherapy (allergy shots or sublingual drops based on allergy testing results) remains the only treatment approach that actually works toward reducing the immune system's reactivity to its specific triggers over time. Many dermatologists recommend combining immunotherapy with symptomatic control treatments while the immunotherapy builds effect, which can take 6 to 12 months to show meaningful results.
For dogs with atopic dermatitis, a full management plan typically includes identifying and avoiding triggers where possible, regular bathing with appropriate shampoos to reduce allergen load on the skin, treating any secondary bacterial or yeast infections that develop from the skin damage caused by scratching, and using a targeted anti-itch medication to reduce the intensity of the itch cycle. Our guide to pet allergy management covers the full picture in detail.
What to Ask Your Vet at Your Next Appointment
If your dog has been struggling with recurrent itching, here are the questions worth raising:
Has atopic dermatitis been properly diagnosed? Distinguishing true atopic dermatitis from food allergy, flea allergy, and contact allergy matters because the management differs. If your dog has not had a formal allergy workup including a food elimination trial, that is worth pursuing alongside any itch-control medication.
Is my dog a candidate for Befrena or Cytopoint? Both are reasonable options. Your vet's choice may depend on your dog's history, whether they have previously tried one and had a suboptimal response, and availability in your area during Befrena's phased launch.
Should we also consider immunotherapy? If your dog has been managing symptoms with medications for more than a year without exploring the underlying cause and allergen identification, immunotherapy is worth asking about. It requires allergy testing, but it is the closest thing to a long-term solution that exists for atopic dermatitis.
Are there any secondary infections to treat? Many itchy dogs have concurrent bacterial or yeast skin infections that make the itch worse. Treating those alongside the allergy medication often produces much faster visible improvement than the medication alone. Our articles on dog skin conditions and managing pet allergies provide more background on this cycle.