FDA Approves “STELFONATA”, Virbac’s New Canine Cancer Treatment for Mast Cell Tumors


According to the Morris Animal Foundation, more than 12 million pets in the United States are diagnosed with cancer each year and it is the leading cause of death in dogs over the age of 2. The most common type of skin cancer found in dogs is a tumor consisting of mass cells, referred to as a “mast cell tumor” (MCT), which was previously only treatable by surgery, chemotherapy, or radiation therapy.

Virbac has recently announced the FDA approval of their tigilanol tiglate injection, STELFONATA, as a novel and effective treatment of canine mast cell tumors. Regulatory agencies in Australia, Europe, and the UK also gave their approval for the injection. STELFONATA is approved for nonmetastatic, cutaneous mast cell tumors anywhere on a dog’s body and nonmetastatic, subcutaneous mast cell tumors in the lower legs (located at or distal to the elbow or hock).

Qbiotics, an Australian life sciences company focused on the development of small molecule anticancer and wound healing pharmaceuticals, discovered the active pharmaceutical ingredient, tigilanol tiglate, in the seed of a native Australian blushwood tree from Northern Queensland’s rainforest. The company is also investigating tigilanol tiglate in a series of human Phase I and Phase II clinical trials targeting head and neck squamous cell carcinoma and melanoma, and there are plans underway for a clinical trial in human soft tissue sarcoma.

Following injection of STELFONATA directly into the tumor, tigilanol tiglate activates the local innate immune system via stimulation of the action of protein kinase C enzymes. These enzymes are involved in regulating processes that help cells grow and survive, so their activation causes the disruption of blood supply to the tumor cells and ultimately leads to their destruction. Following tumor cell ruination, STELFONATA promotes growth of healthy tissue for complete healing with minimal scar formation. The local inflammatory reaction induced by the therapy may lead to pain, bruising, and swelling which can be managed with pain control medications.

STELFONATA’s effectiveness was investigated in a field study that involved 123 dogs. Each had a single new and intact mast tumor measuring up to 10 cm3 in size at the initial treatment. 80 were given the STELFONATA injection, the rest a “dummy treatment”. 4 weeks following that first treatment, 75% of mast cell tumors in dogs given the injection showed a complete response (complete tumor removal). 87% overall showed a complete response after a second dose was given to dogs whose tumors had not disappeared with the first dose. Since the FDA’s approval of STELFONATA, approximately 88% of veterinarians polled in the U.S. who have used the drug reported satisfactory experiences.

This non-surgical therapy offers comfort for owners of senior dogs that may be at increased risk from surgery or chemotherapy and individuals who would prefer to avoid having their dogs put under anesthesia. STELFONATA is now available in veterinary clinics throughout the U.S. and you can visit https://vet-us.virbac.com/stelfonta for further information on the risks and benefits.


-Written by Katie Ball: Researcher for Animal Health Recruiters