Vivesto presents Paccal Vet data at the WSAVA World Congress 2026

About Vivesto AB

Vivesto is a Swedish development company that aims to offer new treatment options for hard-to-treat cancers where there are major medical needs and significant market potential. The project portfolio consists of Cantrixil, which is being developed for blood cancer, and the veterinary oncology program Paccal Vet (paclitaxel micellar), which is being evaluated in a pilot clinical trial in dogs with splenic hemangiosarcoma following splenectomy and in a dose-finding study in cats with solid tumors. Vivesto’s shares are traded on Nasdaq Stockholm (ticker: VIVE). Visit www.vivesto.com for more information about Vivesto.

About Paccal Vet
Vivesto’s drug candidate Paccal Vet consists of paclitaxel formulated with the company’s proprietary XR-17 technology, which enables solubility without the undesirable effects of traditional formulations containing solvents. The absence of the solvent cremophor, to which cats and dogs are particularly sensitive, may reduce the risk of serious side effects and death associated with treatment.

Paccal Vet also does not require the addition of human albumin, which when used in cats and dogs can cause hypersensitivity reactions and reduced treatment effectiveness. Previous clinical studies performed by Vivesto have demonstrated safety in more than 300 dogs. Anti-tumor activity has also been shown in squamous cell carcinoma and non-resectable mammary carcinoma of stage III-V. Vivesto is also conducting a Paccal Vet dose-finding study in cats with solid tumors.

About hemangiosarcoma in dogs
Hemangiosarcoma is one of the most common malignant cancers in dogs and is associated with a poor prognosis, with less than 10 percent of dogs surviving 12 months. The number of dogs diagnosed with hemangiosarcoma annually in the US and Europe is approximately 75,000 per market. Dogs with hemangiosarcoma rarely show clinical symptoms until the tumor has grown very large and spread. Hemangiosarcoma usually affects older dogs (>8 years) of all breeds. The tumor normally appears on the spleen, right heart base or liver, but can also be found on the skin and other sites such as the bones, kidneys, bladder, muscles, mouth and central nervous system.

Treatment options for hemangiosarcoma include surgery and, for some of the dogs, an unapproved adjuvant chemotherapy. The median survival time for dogs with hemangiosarcoma of the spleen undergoing surgery alone is approximately 1-3 months, depending on the stage/seriousness of the disease. No regulatory approved cancer medicines are used for the treatment of hemangiosarcoma in dogs. However, chemotherapeutic agents developed for human use are used off-label in dogs to manage residual metastatic disease after surgery. The most common such chemotherapy program in use today can extend survival with hemangiosarcoma of the spleen by 2-4 months.

About cancer in cats
The need for safe and effective cancer treatment in cats is vast and increasing as the number of pets grows. Estimates indicate that there are more than 95 million cats in the United States alone and approximately 6 million of those are diagnosed with cancer each year. There are currently no approved drugs for the treatment of cancer in cats and current paclitaxel formulations are not tolerated by cats and therefore cannot be used.