Veterinary Sciences (Jun 2022)

Safety and Efficacy of an Oncolytic Adenovirus as an Immunotherapy for Canine Cancer Patients

  • Clara Martín-Carrasco,
  • Pablo Delgado-Bonet,
  • Beatriz Davinia Tomeo-Martín,
  • Josep Pastor,
  • Claudia de la Riva,
  • Paula Palau-Concejo,
  • Noemí del Castillo,
  • Javier García-Castro,
  • Ana Judith Perisé-Barrios

DOI
https://doi.org/10.3390/vetsci9070327
Journal volume & issue
Vol. 9, no. 7
p. 327

Abstract

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The use of oncolytic viruses is an innovative approach to lyse tumor cells and induce antitumor immune responses. Eight dogs diagnosed with carcinoma/adenocarcinoma were intratumorally treated with ICOCAV15, an oncolytic canine adenovirus (CAV). To evaluate the treatment’s safety, a blood count, biochemistry, and coagulation test were performed before treatment and during follow-up. Immune populations were analyzed by flow cytometry. Anti-adenovirus antibodies were also determined. The immune infiltration, vascularization, and viral presence in the tumor were determined by CD3, CD4, CD20, CD31 and CAV by immunohistochemistry. All the dogs maintained a good quality of life during follow-up, and some had increased median survival time when compared with dogs treated with chemotherapy. No treatment-related adverse effects were detected. The Response Evaluation Criteria In Solid Tumors criteria were also assessed: two patients showed a partial response and the rest showed stable disease at various times during the study. ICOCAV15 was detected inside the tumor during follow-up, and antiviral antibodies were detected in all patients. Furthermore, the tumor-infiltrating immune cells increased after viral administration. Therefore, we suggest that intratumorally administered ICOCAV15 could represent as a new tool for the treatment of canine carcinoma because it is safe, well-tolerated by dogs, and shows promising results.

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