Zoetis Launches Portela® in Canada and Europe, Introducing the First Long-Acting Anti-NGF Therapy for Feline Osteoarthritis Pain
Zoetis Inc. has announced the commercial launch of Portela® (relfovetmab) across Canada and the member states of the European Union, marking an important advancement in the management of osteoarthritis (OA) pain in cats. The new therapy is the world’s first long-acting anti-nerve growth factor (NGF) monoclonal antibody specifically developed to provide extended pain relief for feline patients suffering from osteoarthritis. Designed to deliver up to three months of pain control following a single subcutaneous injection, Portela offers veterinarians and pet owners an innovative treatment option for one of the most common yet underdiagnosed chronic conditions affecting aging cats.
The launch represents the culmination of nearly a decade of scientific research and clinical development by Zoetis, one of the world’s leading animal health companies. Clinical studies demonstrated that Portela effectively reduced osteoarthritis-associated pain, with many treated cats showing measurable improvements in mobility and comfort within just three days after receiving their first injection. By combining long-lasting efficacy with a convenient dosing schedule, the therapy has the potential to improve treatment adherence while enhancing the quality of life for millions of cats living with chronic joint disease.
Addressing a Widespread but Often Overlooked Disease
Osteoarthritis is one of the most prevalent chronic musculoskeletal disorders in companion animals. The progressive condition causes gradual deterioration of cartilage within the joints, resulting in inflammation, stiffness, chronic pain, and reduced mobility. Although osteoarthritis is frequently associated with older pets, studies have shown that the disease can affect cats of various ages, becoming increasingly common as animals grow older.
Unlike dogs, however, cats rarely display obvious signs of discomfort. Their natural instinct to conceal pain—a survival behavior inherited from their wild ancestors—often makes diagnosis particularly challenging. Instead of limping or vocalizing pain, affected cats may simply become less active, avoid climbing stairs or jumping onto furniture, groom themselves less frequently, or spend more time resting. Because these subtle behavioral changes are often mistaken for normal aging, osteoarthritis frequently goes undetected for extended periods.
Research indicates that as many as 40% of all cats may be clinically affected by osteoarthritis during their lifetime. Despite this high prevalence, only approximately 18% of cats experiencing osteoarthritis-related pain are formally diagnosed by veterinary professionals. This diagnostic gap leaves countless animals living with chronic pain that could potentially be managed through appropriate treatment.
Understanding the Role of Nerve Growth Factor
Portela was developed to address the biological mechanisms responsible for chronic pain rather than simply managing symptoms.
The therapy targets nerve growth factor (NGF), a naturally occurring protein that plays a central role in transmitting pain signals and promoting inflammation within affected joints. Elevated NGF levels have been strongly associated with chronic pain conditions, including osteoarthritis.
Portela is a monoclonal antibody specifically engineered to bind to a unique site on NGF. By blocking NGF activity, the therapy interrupts pain signaling pathways before they reach the nervous system, helping reduce discomfort while allowing affected cats to regain mobility and improve their daily function.
Unlike traditional pain medications that often require frequent oral administration, Portela delivers sustained therapeutic activity following a single injection, providing pain relief for as long as three months.
Clinical Development Supported by Years of Research
The commercial launch follows nearly ten years of scientific investigation and product development focused on improving long-term pain management for cats.
The therapy’s effectiveness was demonstrated in a pivotal nine-month European field study evaluating cats diagnosed with osteoarthritis. Results showed that Portela successfully alleviated OA-associated pain, with improvements becoming apparent as early as Day 3 after treatment.
Throughout the clinical program, the medication was also found to be well tolerated, with safety findings supporting its use as a long-acting injectable treatment for chronic pain management.
The combination of rapid onset and prolonged duration of action distinguishes Portela from many existing treatment approaches currently available in veterinary medicine.
A New Approach to Long-Term Pain Management
Managing chronic diseases such as osteoarthritis presents unique challenges for both veterinarians and pet owners.
Many current therapies require daily or frequent oral medication, which can become difficult over months or years of treatment. Cats are particularly known for resisting oral medications, creating considerable stress for both animals and caregivers. Missed doses and inconsistent administration frequently reduce treatment effectiveness and may allow pain to return.
Portela addresses this challenge by providing sustained pain relief through a single injection administered once every three months.
This significantly reduces the burden of treatment while helping maintain consistent therapeutic coverage throughout the dosing interval.
For veterinary professionals, the simplified dosing schedule may improve compliance while enabling more predictable long-term pain management strategies.
Improving Quality of Life for Aging Cats
Advances in veterinary medicine, nutrition, and preventive healthcare have significantly increased the average lifespan of domestic cats.
As feline populations continue aging, age-related conditions such as osteoarthritis are becoming increasingly common. Chronic joint pain not only affects physical mobility but also influences emotional well-being, appetite, grooming habits, social interactions, and overall quality of life.
Effective pain management allows many affected cats to resume behaviors that owners often miss, including climbing, jumping, playing, grooming, and interacting comfortably with family members.
By extending the duration of pain control, Portela aims to help cats remain active and comfortable while minimizing interruptions in therapy.
Zoetis Expands Its Osteoarthritis Portfolio
The launch of Portela further strengthens Zoetis’ leadership position in veterinary pain management.
The company has invested heavily in developing monoclonal antibody therapies targeting osteoarthritis pain in companion animals.
Portela joins the company’s existing feline osteoarthritis treatment portfolio alongside Solensia® (frunevetmab), another anti-NGF monoclonal antibody indicated for monthly pain relief in cats.
Although both therapies target NGF, Portela binds to a different site on the protein, enabling a substantially longer duration of action.
While Solensia is administered monthly, Portela requires treatment only once every three months, offering veterinarians greater flexibility when tailoring treatment plans to individual patients and owner preferences.
The expanded portfolio reflects Zoetis’ broader commitment to developing innovative biologic therapies that address chronic diseases in companion animals.
Company Perspective
Commenting on the launch, Jamie Brannan, Executive Vice President and Chief Commercial Officer at Zoetis, emphasized the ongoing challenge of recognizing feline osteoarthritis.
He noted that many cats instinctively hide signs of pain, contributing to underdiagnosis across veterinary practices worldwide.
According to Brannan, Portela represents another important step toward closing that treatment gap by providing veterinary professionals with a long-acting injectable therapy specifically designed for feline patients. The treatment helps address many of the practical challenges associated with daily medication while supporting continuous pain control over an extended period.
He added that the launch reinforces Zoetis’ commitment to advancing innovative healthcare solutions that improve the lives of companion animals and simplify treatment for caregivers.
Veterinary Experts Highlight Practical Benefits
Veterinary specialists also recognize that successful long-term osteoarthritis management depends not only on treatment effectiveness but also on practicality.
Dr. Marisa Palmero, Medical Director of Gattos Hospital in Spain and a specialist in feline medicine, explained that the earliest signs of osteoarthritis frequently appear as subtle behavioral changes rather than obvious physical symptoms.
Cats may begin sleeping longer, avoiding elevated surfaces, reducing grooming, or becoming less interested in activities they previously enjoyed.
According to Dr. Palmero, educating pet owners about these early warning signs is essential for improving diagnosis and initiating treatment before mobility declines further.
She also emphasized that therapies designed around the realities of feline care—including fewer veterinary visits and elimination of daily oral medication—may help families remain committed to long-term treatment while improving comfort and mobility for affected cats.
Meeting an Unmet Need in Veterinary Medicine
Despite increasing awareness of feline osteoarthritis, significant unmet needs remain within veterinary pain management.
Many cats continue living with untreated or inadequately treated chronic pain due to delayed diagnosis, medication compliance challenges, or limitations of existing therapies.
Long-acting biologic medicines such as Portela may help bridge these gaps by combining targeted molecular therapy with a convenient administration schedule.
As veterinarians increasingly adopt proactive screening for age-related diseases, the availability of longer-lasting treatment options is expected to play an important role in comprehensive feline healthcare.
Supporting Future Innovation
Portela also reflects Zoetis’ broader strategy of combining scientific innovation, geographic expansion, and lifecycle management to address evolving medical needs in animal health.
The company continues investing in research across multiple therapeutic areas, including pain management, infectious diseases, dermatology, oncology, and chronic inflammatory conditions affecting companion animals and livestock.
The successful launch of Portela demonstrates the growing role of monoclonal antibody therapies within veterinary medicine, where biologic treatments are becoming increasingly important alternatives to traditional pharmaceuticals.
The commercial introduction of Portela in Canada and the European Union marks a significant advancement in feline osteoarthritis care. As the first long-acting anti-NGF monoclonal antibody capable of providing up to three months of pain relief following a single injection, the therapy addresses many of the longstanding challenges associated with diagnosing and managing chronic pain in cats.
Supported by nearly a decade of research and positive clinical trial results, Portela offers veterinarians an innovative tool to improve long-term pain control while reducing treatment burden for pet owners. As awareness of feline osteoarthritis continues to grow and more cats benefit from earlier diagnosis, the availability of convenient, long-lasting therapies such as Portela has the potential to transform chronic pain management and enhance the health, mobility, and quality of life of aging feline companions worldwide.
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.