Vaccination Against Extracellular Vimentin Plus Doxorubicin for Canine Hemangiosarcoma

Area of Science:

• Veterinary Oncology
• Immunotherapy
• Soft Tissue Sarcomas

Background:

• Angiosarcomas are aggressive soft tissue tumors with poor outcomes in dogs and humans.
• Visceral hemangiosarcoma in dogs serves as a valuable model for preclinical cancer therapy research.
• Current treatments like surgery and doxorubicin (DOX) offer limited survival benefits.

Purpose of the Study:

• To evaluate the efficacy and safety of combining DOX with an extracellular vimentin (eVim) immune Boost (iBoost) vaccine in dogs with visceral hemangiosarcoma.
• To determine if this combination therapy improves survival rates compared to historical controls treated with DOX alone.

Main Methods:

• Twenty-three dogs with hemangiosarcoma received DOX chemotherapy and eVim iBoost immunotherapy post-splenectomy.
• The combination therapy involved six cycles of DOX and four doses of eVim iBoost, followed by maintenance vaccinations.
• Outcomes were compared to historical control data from dogs treated with DOX alone.

Main Results:

• The combination therapy demonstrated a significant increase in 1-year survival rate (44% vs. 14%) and restricted mean survival time (p=0.02).
• Median overall survival time increased from 136 to 235 days, though not statistically significant (NS).
• The combined treatment was well-tolerated, with no observed systemic vaccine-related toxicity.

Conclusions:

• Combining eVim iBoost immunotherapy with doxorubicin chemotherapy improves survival outcomes in dogs with hemangiosarcoma without increasing toxicity.
• These findings support further clinical development of this combination therapy for both canine and human angiosarcoma.
• The study highlights the potential of targeted immunotherapy in enhancing conventional cancer treatments.