Vivesto completes recruitment in Paccal Vet dog pilot study – topline results expected Q3 2026

VIVEPress release26.06.2026 klo 09.00

Solna, Sweden, June 26, 2026 – Vivesto AB, an oncology-focused development company, today announced the completion of recruitment to its clinical Paccal Vet pilot study in dogs with splenic hemangiosarcoma following splenectomy. Topline results from the study are expected during Q3 2026.

Eighteen-nineteen evaluable dogs have now been enrolled to the open label, exploratory pilot study evaluating Paccal Vet (paclitaxel micellar) in dogs with splenic hemangiosarcoma (HSA) following splenectomy. In the study, dogs with HSA are treated with up to 4 treatment cycles of Paccal Vet in intervals of 3 weeks across 8 clinical sites in the US. Overall survival and progression free survival is followed for up to 12 months.

“Completing recruitment marks an important execution milestone for the Paccal Vet program. We now look forward to the topline data during Q3 2026. The topline data will guide the next step in our ambition to bring a new treatment option for dogs diagnosed with this devastating and currently under-served cancer disease,” said Erik Kinnman, CEO of Vivesto. “The upcoming topline data will also be important in the ongoing partnering activities together with Liberi Group, in which discussions with leading players in the field are already underway."

In November 2025, Vivesto reported positive interim results from the study, indicating that treatment with Paccal Vet leads to longer overall survival in dogs with Stage I-II splenic hemangiosarcoma following splenectomy, compared with surgically treated historical controls.

Confirmation of the positive interim results would trigger initiation of a pivotal study to support full marketing approval for Paccal Vet in dogs with splenic hemangiosarcoma. Positive results may also open the path to conditional approval and early market entry ahead of pivotal study completion.

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.