The University of Guelph’s Ontario Veterinary College recently entered an 8-year-old Rottweiler named Cujo into a clinical trial headed by the U.S. National Cancer Institute’s Comparative Oncology Trials Consortium (NCI COTC). It’s the first such collaboration between the college and the NCI COTC. The study, funded by the Morris Animal Foundation, will include about 160 dogs from 21 veterinary teaching hospitals across North America. Researchers will evaluate the effectiveness of the therapeutic agent rapamycin for treating osteosarcoma in dogs by delaying or preventing metastases. The trial is expected to last about eight to 12 months. “This is exciting for us,” said Paul Woods, DVM, Dipl. ACVIM, a veterinary cancer specialist at OVC and co-director of U of G’s Institute for Comparative Cancer Investigation. “Our goal is to improve the dogs’ quality and quantity of life while living with cancer.” Dogs, especially large breeds, develop osteosarcoma 10 times as often as humans, according to the college. OVC’s Animal Cancer Center sees up to three new osteosarcoma cases each week, the college further noted. “We’re not sure why it’s so common in large dogs,” Dr. Woods said. Despite aggressive treatments such as limb amputation and chemotherapy, most dogs still die from metastatic disease, which usually appears in the lungs, according to the college. Rapamycin has been used in kidney transplant patients as an immunosuppressant, and, more recently, it’s being utilized as an anti-tumour agent, Woods said. Rapamycin inhibits a cellular pathway that is a critical regulator of cell growth, proliferation, metabolism and survival, he said. “We are looking to see if rapamycin slows down or even prevents the metastases of osteosarcoma from coming back,” Woods said. The clinical trial will compare dogs receiving standard of care treatment alone (amputation and chemotherapy with carboplatin) with dogs receiving standard of care along with rapamycin. Cujo was selected to receive standard of care treatment. Once the NCI COTC confirms eligibility of a patient, the patient is then randomly assigned to receive standard of care treatment or standard of care plus rapamycin, according to the college. Cujo’s amputation occurred in December 2015. He also received four treatments of chemotherapy every three weeks from December to March. Cujo was reportedly doing well at press time. Thoracic radiographs have shown no evidence of the disease, the college noted. He’ll continue to be monitored. Since Cujo’s enrollment, OVC’s Animal Care Center has enrolled five additional dogs, distributed in both arms of the study.
