FDA Paves Way for New Canine Cancer Drug in the US Market

NEW YORK, NY – February 09, 2026 – The U.S. Food and Drug Administration (FDA) has granted a key designation to a promising canine cancer therapy, potentially opening the door for its entry into the American market and offering a new option for dogs battling a common form of the disease. French pharmaceutical company AB Science announced that its drug, Masivet®, received Minor Use in Major Species (MUMS) status for treating canine mast cell tumors.

This regulatory milestone provides a clear pathway for a drug that is already established and profitable in Europe, signaling a significant strategic step for AB Science and a ray of hope for pet owners and veterinarians across the United States.

A Targeted Approach to a Common Canine Cancer

Mast cell tumors (MCTs) are one of the most frequently diagnosed skin cancers in dogs, accounting for up to 21% of all skin tumor cases. While surgery and radiation are common first-line treatments, they are not always viable, especially for tumors that are inoperable due to their size or location, or for more aggressive, high-grade cancers that have spread.

Masivet® offers a more modern approach. As a protein kinase inhibitor (PKI), it is a form of targeted therapy designed to block the activity of specific molecules involved in cancer growth. The drug specifically inhibits mutations in a receptor called c-kit, a primary driver of mast cell tumor development in dogs. This precision allows it to attack cancer cells while minimizing damage to surrounding healthy tissue, a significant advantage over traditional chemotherapy.

In Europe, where Masivet® was first approved by the European Medicines Agency in 2008, it has built a long and successful track record. It was the first targeted therapy ever approved in veterinary oncology, and since then, tens of thousands of dogs have been treated. Clinical data and real-world use have shown it can significantly extend survival times, with European studies indicating an increase in median survival of 300 days compared to placebo for dogs with aggressive, non-resectable tumors.

Veterinarians familiar with the drug in Europe have noted its effectiveness. "It's an amazing drug when it works," commented one veterinary oncology specialist, highlighting its particular strength against c-Kit positive tumors. For pet owners, the oral tablet formulation offers the convenience of at-home administration, improving the quality of life for both the pet and its family during a difficult time.

Unlocking the Market Through the MUMS Pathway

The MUMS designation is a critical tool created by the FDA's Center for Veterinary Medicine to encourage the development of drugs for less common diseases in major species like dogs, or for use in minor species. Enacted in 2004, the program functions as the veterinary equivalent of the "Orphan Drug" designation in human medicine, providing powerful incentives to overcome the financial hurdles of developing treatments for limited markets.

For AB Science, this status makes Masivet® eligible for grants to help fund the costly studies required for full U.S. approval. More importantly, upon receiving approval, the company will be granted seven years of exclusive marketing rights for this specific use. This exclusivity provides a protected window to establish the drug and recoup development costs.

The pathway often involves a "conditional approval" phase, which allows a drug to be marketed after demonstrating a reasonable expectation of effectiveness while the manufacturer collects the final data required for full approval. This process can take several years, as seen with Laverdia, a treatment for canine lymphoma that received conditional approval in 2021 and gained full approval in early 2026 after its sponsor completed the necessary studies. AB Science will likely follow a similar regulatory journey.

A Strategic Linchpin for AB Science's Future

While the medical benefits for dogs are clear, the MUMS designation is also a major strategic victory for AB Science. The Paris-based company has a broad pipeline focused on protein kinase inhibitors, with its lead compound, masitinib (the active ingredient in Masivet®), also being developed for a range of human diseases in oncology, neurology, and inflammatory conditions.

Developing human drugs is a long and expensive process. According to the company's financial reports, its operating income currently comes exclusively from its profitable veterinary medicine sales in Europe. In the press release, CEO Alain Moussy stated, “The MUMS status delivered by FDA is an encouragement to develop Masivet® in the USA.” The company explicitly noted that it expects the revenue generated from a potential U.S. launch to help cover its fixed costs, thereby contributing to the "auto-financing and derisking" of its entire portfolio, including its human-focused programs.

This move is part of a broader global expansion strategy for the animal health franchise. AB Science is also pursuing distribution agreements in Scandinavia, Latin America, Asia, and South Africa, signaling its intent to make Masivet® a worldwide brand and a cornerstone of the company's financial stability.

Navigating a Competitive Veterinary Oncology Market

Entering the U.S. will not be without challenges. The American veterinary oncology market is robust, valued at over USD 400 million and growing steadily as pet owners increasingly seek human-level care for their animals. This has fostered a competitive environment.

Masivet® will face a direct competitor in Palladia® (toceranib phosphate), a drug from veterinary giant Zoetis. Palladia® was the first FDA-approved targeted therapy for canine mast cell tumors in the U.S., hitting the market in 2009. It also functions as a tyrosine kinase inhibitor targeting the c-kit receptor, giving it a similar mechanism of action to Masivet®.

Furthermore, this is not masitinib's first appearance in the U.S. It was previously marketed under the name Kinavet during a conditional approval period but was later withdrawn from the market. AB Science will need to successfully navigate the regulatory process and clearly differentiate Masivet® from its established competitor to gain traction with American veterinarians. The company will likely lean on its decade-plus of European safety and efficacy data to make its case.

Ultimately, the FDA's MUMS designation for Masivet® represents a convergence of medical innovation and smart regulatory policy. While the road to full approval and market success is still ahead, this development brings a new, proven therapeutic option one step closer to U.S. veterinary clinics, offering a potential new standard of care for dogs and their devoted owners facing a difficult cancer diagnosis.