Vivesto’s positive dog topline results support continued development and strengthen partnering prospects for Paccal Vet
Vivesto’s positive dog topline results support continued development and strengthen partnering prospects for Paccal Vet
Solna, Sweden, September 15, 2026 – Vivesto AB, an oncology-focused development company, today announced positive topline results from its open label clinical pilot study evaluating Paccal Vet in dogs with splenic hemangiosarcoma following splenectomy. The results confirm the previously reported interim data and support continued clinical development towards regulatory approval, while bolstering ongoing business development activities.
The topline analysis of 26 dogs confirms the positive survival trend observed in the interim analysis from the first 11 dogs, previously reported in November 2025. Treatment with Paccal Vet (paclitaxel micellar) resulted in a median overall survival of 135 days in dogs with Stage I-II splenic hemangiosarcoma following splenectomy, representing prolonged survival compared to surgically treated historical controls and supporting continued development towards a pivotal registration study.
“These positive topline results confirm the encouraging efficacy signal we observed in the interim analysis and represent an important value inflection point for the Paccal Vet program,” said Erik Kinnman, CEO of Vivesto. "The data support continued development toward registration and strengthen the commercial attractiveness of the program. Together with Liberi Group, we will now intensify our partnering activities and broaden our outreach to potential commercial partners."
A total of 26 dogs (Stage I-II) were included in the survival analysis. Of these, four dogs remain in active follow-up and continue to contribute to the survival analysis. Final results from the study are expected by the end of the year, but could be received later depending upon how long the remaining dogs are progression free or alive. As these dogs remain in the study, the final study results may demonstrate an even greater treatment benefit than reflected in the current topline analysis.
Overall, the safety findings were considered tolerable with proactive monitoring and supportive care when necessary. Most dogs experienced side effects commonly associated with chemotherapy, including decreased appetite, neutropenia (a temporary reduction in white blood cells) and diarrhea. Most side effects were temporary, resolved before the next treatment cycle and could be managed with supportive medication. A small number of dogs experienced serious side effects requiring urgent medical attention, particularly at higher doses. No hypersensitivity reactions were observed.
The confirmation of the positive interim results supports the initiation of a pivotal study aimed at obtaining full marketing approval for Paccal Vet in dogs with splenic hemangiosarcoma. Positive final results may also open the path to conditional approval and early market entry ahead of pivotal study completion.