First long-acting anti-NGF monoclonal antibody therapy for cats offers three months of osteoarthritis pain relief with a single injection

Zoetis Inc. (NYSE:ZTS) today announced the commercial launch of Portela^® (relfovetmab) in Canada and the European Union (EU) member states. Portela is the first long-acting anti-nerve growth factor (NGF) monoclonal antibody (mAb) therapy for cats, designed to alleviate pain associated with osteoarthritis (OA) for up to three months with a single subcutaneous injection. Backed by nearly a decade of science and research, Portela demonstrated effectiveness in alleviating OA pain in a pivotal nine-month European field study with improvements observed from as early as Day 3 after the first injection¹.

Portela targets NGF, a recognized mediator of pain and inflammation. By binding to a novel site on NGF, Portela enables up to three months of OA pain relief with a single injection. In clinical trials, Portela was found to be well tolerated and demonstrated effectiveness in alleviating OA pain.

Significance of Osteoarthritis Pain

Osteoarthritis is a common, chronic and progressive joint disease characterized by the inflammation and breakdown of joints, leading to pain and mobility issues. Chronic pain can be difficult to recognize and assess in companion animals². Up to 40% of all cats may be clinically affected by OA^3,4, yet these signs are often overlooked by pet owners, and as a result only 18% of affected cats are diagnosed with OA pain by veterinary professionals⁵. Cats are naturally inclined to mask pain, and many owners interpret reduced activity or reluctance to jump as normal aging rather than signs of a treatable condition⁶. Additionally, administering regular oral medication to cats presents a well-known compliance challenge^7,8, which results in many cats with OA going undertreated⁶.

Effective pain management can meaningfully improve quality of life for affected cats⁹. As cats live longer due to advances in veterinary care and nutrition, the number of senior cats is growing^10,11. With age, conditions such as osteoarthritis become more common - highlighting the need for safe, effective long-term pain management options. For millions of cat owners across Europe and Canada, the impact on their cats’ quality of life is impossible to ignore. Medications that are more convenient in delivering sustained pain control for this chronic disease fill an unmet need to achieve increased compliance with treatment.

A longer-acting option for a chronic condition

"Feline osteoarthritis remains one of the most underdiagnosed conditions in veterinary medicine, in part because cats instinctively hide signs of pain," said Jamie Brannan, Executive Vice President and Chief Commercial Officer of Zoetis. "Portela reinforces our commitment to closing that gap – giving veterinary professionals a long-acting injectable option specifically designed for cats – helping address day-to-day dosing challenges for some pet owners and supporting sustained pain management over time."

Continued innovation to meet medical needs

Zoetis continues to advance care for animals around the globe with a robust pipeline fueled by lifecycle innovation, geographic expansion and new innovation. Building on its broad portfolio in osteoarthritis (OA) pain, Portela expands the company’s feline OA pain portfolio alongside Solensia^® (frunevetmab), an anti-NGF monoclonal antibody indicated for monthly alleviation of OA pain in cats. Portela is designed to provide pain relief for a longer period of time by binding to a different site on NGF, offering the convenience of a single injection once every three months.

"For many cats, osteoarthritis pain shows up first as subtle behavior changes - sleeping more, grooming less, avoiding stairs or high surfaces - so proactive screening and owner education are critical," said Marisa Palmero, DVM, AVEPA Accredited in Feline Medicine, Spec. EaMIS, GPCert (FelP), (ISVPS) – PGCert Fel.Med (IFEVET), Medical Director, Gattos Hospital, Spain. "When treatment fits the realities of feline care - minimizing repeated travel to the clinic and avoiding the day-to-day struggle of oral dosing - it can help families stay consistent and help cats maintain comfort and mobility over time."

About Portela

Portela (relfovetmab) is a monoclonal antibody therapy for the alleviation of pain associated with osteoarthritis in cats. Portela binds to NGF to reduce its effects. Portela is administered as a subcutaneous injection once every three months. Portela should not be used in cats with known hypersensitivity to relfovetmab, or breeding, pregnant or lactating cats, or cats less than 12 months of age. Based on clinical trial studies conducted for global development and the assessment of the different regulatory agencies, the most common side effect reported in the EU product label information is immediate pain upon injection (very common: more than 1 in 10 cats treated), followed by dermatitis (common: 1–10 cats per 100 treated). Uncommon side effects (1–10 cats per 1,000 treated) included pruritus, skin scabs, injection site swelling and injection site hair loss. In Canada, the Client Information Sheet (CIS) reports the following clinical signs as possible side effects in cats receiving Portela: injection site pain, skin infection, hair loss and dermatitis, and decreased appetite.

For full clinical and safety information, including indications, contraindications, special warnings and full list of adverse events, please refer to the product labeling in your jurisdiction. Portela should be used under the guidance of a veterinary professional. Click here for the EU Summary of Product Characteristics. For the Canadian Product Information, visit the Drug Product Database.

About Zoetis

Zoetis is the world’s leading animal health company, driven by a singular purpose: to nurture our world and humankind by advancing care for animals. With a legacy of nearly 75 years, Zoetis continues to pioneer ways to predict, prevent, detect, and treat animal illness, supporting veterinarians, livestock producers, and pet owners in over 100 countries. We integrate deep scientific expertise, data-driven R&D, advanced manufacturing, robust post marketing surveillance (PV), and commercial excellence to deliver meaningful innovation across medicines, vaccines, diagnostics, biopharmaceuticals, and digital solutions. Guided by our vision to be the most trusted and valued animal health company, Zoetis is committed to setting new standards for the future of animal care through innovation, customer obsession, and purpose-driven colleagues. To learn more, visit Zoetis.com.

¹ Zoetis Data on File. Portela EU Summary of Product Characteristics (SPC).

²Lascelles BDX, Brown DC, Conzemius MG, Gill M, Oshinsky ML, Sharkey ML. Measurement of chronic pain in companion animals: discussions from the Pain in Animals Workshop (PAW) 2017. Vet J. 2019;250:71-78.

³ Enomoto M, Mantyh PW, Murrell J, Innes JF, Lascelles BDX. Anti-nerve growth factor monoclonal antibodies for the control of pain in dogs and cats. Vet Rec. 2019;184(1):23.

⁴ L.I. Slingerland, H.A.W. Hazewinkel, B.P. Meij, Ph. Picavet, G. Voorhout, Cross-sectional study of the prevalence and clinical features of osteoarthritis in 100 cats. The Veterinary Journal, Volume 187, Issue 3, 2011, Pages 304-309.

⁵ Solensia Veterinarian A&U MR (MARC 2025)

⁶ Bennett D, Zainal Ariffin SM bt, Johnston P. Osteoarthritis in the cat 1. How common is it and how easy to recognise? J Feline Med Surg. 2012;14:65-75. doi:10.1177/1098612X11432828

⁷Odom TF, et al. Medication compliance by cat owners prescribed treatment for home administration. J Vet Intern Med. 2025;39(1):e17298. doi:10.1111/jvim.17298

⁸Taylor S, Caney S, Bessant C, Gunn-Moore D. Online survey of owners’ experiences of medicating their cats at home. J Feline Med Surg. 2022;24(12):1283-1293. doi:10.1177/1098612X221083752

⁹Gruen, M. E., Myers, J. A. E., Tena, J. S., Becskei, C., Cleaver, D. M., & Lascelles, B. D. X. (2021). Frunevetmab, a felinized anti-nerve growth factor monoclonal antibody, for the treatment of pain from osteoarthritis in cats. Journal of veterinary internal medicine, 35(6), 2752–2762. https://doi.org/10.1111/jvim.16291

¹⁰ Han, H. J. (2025). Toward a new era of companion animal longevity and well-being. Journal of Veterinary Science, 26(Suppl 1), S1–S4.

¹¹ Oh, W. S., & Armstrong, P. J. (2025). Geroscience and aging interventions in dogs and cats: from mechanisms to clinical care. Journal of Veterinary Science, 26(Suppl 1), S157–S180.

DISCLOSURE NOTICES

Forward-Looking Statements: This press release contains forward-looking statements which reflect the current views of Zoetis with respect to: our business plans or prospects; expectations regarding products, product approvals or licenses, products under development; and other future events. These statements are not guarantees of future performance or actions. Forward-looking statements are subject to risks and uncertainties. If one or more of these risks or uncertainties materialize, or if management’s underlying assumptions prove to be incorrect, actual results may differ materially from those contemplated by a forward-looking statement. Forward-looking statements speak only as of the date on which they are made. Zoetis expressly disclaims any obligation to update or revise any forward-looking statement, whether as a result of new information, future events or otherwise. A further list and description of risks, uncertainties and other matters can be found in our most recent Annual Report on Form 10-K, including in the sections thereof captioned "Forward-Looking Statements and Factors That May Affect Future Results" and "Item 1A. Risk Factors," in our Quarterly Reports on Form 10-Q and in our Current Reports on Form 8-K. These filings and subsequent filings are available online at www.sec.gov, www.zoetis.com, or on request from Zoetis.

ZTS-COR

ZTS-IR

ZTS-CA

ZTS-PS

View source version on businesswire.com: https://www.businesswire.com/news/home/20260722074668/en/

Media Contacts:

Jennifer Albano

1-862-399-0810 (o)

Jennifer.albano@zoetis.com

Laura Panza

1-973-975-5176 (o)

Laura.panza@zoetis.com

Investor Contacts:

Steve Frank

1-973-822-7141 (o)

steve.frank@zoetis.com

Nick Soonthornchai

1-973-443-2792 (o)

nick.soonthornchai@zoetis.com