A new alternative cell-based cancer vaccine developed by researchers at the University of Pennsylvania’s schools of Medicine and Veterinary Medicine is showing an increase in survival time for dogs with spontaneous non-Hodgkin’s lymphoma.

The research team tested the experimental vaccine in dogs with newly diagnosed non-Hodgkin’s lymphoma, according to a news release The team vaccinated the dogs three times, three weeks apart, after standard induction chemotherapy and confirmation of clinical remission. They then tracked the dogs over several years to see if the vaccine prevented relapse while prolonging survival.

Nicola Mason, assistant professor of medicine at Penn Vet, led the team in their study.

"We found that, although the vaccinated dogs sill relapsed with clinical disease when they were treated with rescue chemotherapy, they had significantly increased overall survival times when compared to an unvaccinated control group," Mason said in the news release. "Some of these dogs are still alive and cancer-free more than three years later."

While both vaccinated and unvaccinated dogs relapsed with the disease at the same time, 40 percent of the vaccinated dogs that relapsed experienced long-term survival after a second round of chemotherapy. Only 7 percent of unvaccinated dogs that relapsed survived long term after being treated with the same chemotherapy.

The vaccine is made of cultured B-cells from the blood of the diseased dogs. The cells were then loaded with RNA isolated from the patient’s own tumor.

While the results of the study are encouraging, Mason said, the real excitement is in future research that may produce even better results.

"These dogs just received three doses of vaccine, three weeks apart," Mason said. "If we kept boosting the immune system in this way by vaccination, perhaps the dogs would not relapse in the first place."

Read the full news release from the University of Pennsylvania here.