Denali, a 10-year-old Spinone, was the first dog to enroll in Dr. Nicola Mason’s clinical trial for dogs with osteosarcoma who had not undergone amputation.
Until Denali fractured his right front leg (proximal humerus), his owners didn’t know that he had any serious problems. The radiographic diagnosis of pathological fracture secondary to osteosarcoma was a complete shock.
His owners, the Ipcars, had owned a Mastiff before Denali came into their lives and that dog had died from the complications of bone cancer, even after an amputation of the limb and chemotherapy. The experience had been emotionally draining for them and physically compromising for their dog.
As a result, they decided to stabilize Denali’s limb with a metal pin and 2 plates and treat Denali with pain medications for the next few months before letting him go.
But that’s when they heard about an osteosarcoma clinical trial taking place at Penn Vet. Dr. Nicola Mason, associate professor and clinician at Penn Vet’s Ryan Hospital, had moved into a second phase of research on the impact of immunotherapy on canine osteosarcoma. In the first phase of this research, Dr. Mason had studied the effect of an immunotherapeutic approach to treating dogs with osteosarcoma after they had been amputated and received chemotherapy. The aim was to use the body’s own immune system to kill remaining cancer cells in the body and prevent metastatic disease.
Dogs who underwent amputation and chemotherapy received a series of immune boosting vaccines and the preliminary results have been very encouraging. Several dogs are now alive 3 years after their initial diagnosis with no signs of cancer returning. The immunotherapy had been undeniably effective in prolonging a good quality of life in many of the dogs treated in this first trial.
In the second phase of the research, Dr. Mason is studying the effects of her immunotherapy protocol on dogs who are unable to undergo amputation, due to their large size or owner preference not to pursue surgery.
The trial is unique – dogs are required to have a biopsy to confirm the diagnosis of osteosarcoma, they receive two doses of radiation on two consecutive days and are then vaccinated once every three weeks for a total of eight vaccines. There is no chemotherapy in this clinical protocol.
Designed to stimulate his immune system to recognize osteosarcoma cancer cells, Denali’s treatment course began in early January 2014. Side effects were minimal. He ran a fever and suffered mild nausea on occasion. When the fever subsided, he was discharged from Ryan Hospital and his owner drove him back to Brooklyn, all in the same day.
Midway through his treatment, Denali’s x-rays and tests revealed no metastatic spread of cancer to his lungs. He had minimal pain on palpation of his right forelimb although he did have some mild lameness, probably more due to the healing of the fracture.
“He goes up and down stairs in one fell swoop and even jumps up onto the bed,” said Robert Ipcar. "We took him to the beach and shot some footage of him. Repeat radiographs show that his fracture is healing and his tumor does not appear to be any bigger than before.”