Hope for humans, with help from dogs

Penn researchers Nicola Mason, Robert Vonderheide and Karin Sorenmo Penn researchers Nicola Mason, Robert Vonderheide and Karin Sorenmo believe a cancer vaccine they recently tested with strong results in dogs could one day also be used in humans.
Photo credit: Candace diCarlo

Vets helping pets to help their owners in the long run is how Nicola Mason describes the unique partnership between Penn School of Medicine Assistant Professor Robert Vonderheide and the School of Veterinary Medicine.

It’s a partnership that took shape after Vonderheide, a researcher at Penn’s Abramson Cancer Center, met Mason and Karin Sorenmo, associate professor of oncology at the vet school, at a Grand Rounds event.

“I met some of the veterinary oncologists there,” Vonderheide says. “And they were quite interested in helping to pioneer new therapies.”

Specifically, Vonderheide was interested in the possibilities of a cancer vaccine called B cell lymphocytes. So today, Vonderheide, Mason and Sorenmo are testing B cell therapy in dogs that have lymphoma—in hopes that the vaccine may one day be used to also help treat humans with cancer. Vonderheide sees the vaccine eventually working in conjunction with standard treatment, like chemotherapy and radiation.

“If we can show in dogs that the vaccine is safe and potentially effective, then we can test to see if it is also effective as a new type of treatment for human cancer,” Vonderheide says.

The vaccine is administered by removing immune cells from a patient’s blood, activating the cells in the lab and then putting the activated cells back into the patient to trigger an anti-tumor response. Testing with animals is fairly common, but there is something that makes this particular research unique.

“The difference here is these are privately owned animals, not laboratory owned,” Vonderheide says. “These are people’s pets that developed cancer.”

The effect of cancer in dogs is very similar to cancer in humans.
“Animals reflect what happens to humans,” Mason says. “Non Hodgkin’s lymphoma affect people and dog populations, generally speaking, in clinical presentations and disease progression, very similarly.”

One of the big variables in the research is the ability to secure funding. They have already received a pilot grant of $500,000, which was just enough to pay for the first pilot study. “If we can secure additional grant funding, this could go forward in patients in the next two to three years,” Vonderheide says.

Currently 23 dogs are enrolled. Vonderheide and Mason would like to enroll a total of 50 dogs for a full data set. Dogs must meet strict criteria to be eligible, and cannot, for example, have circulating tumor cells in their blood. “Some of those dogs will not make it to the vaccination stage,” Mason says. “They’ll fail induction chemotherapy. They have to go into clinical remission before they can receive the vaccine.”

Side effects of the vaccine have been minimal. One dog recently experienced some vomiting, but Mason says it was difficult to say that was directly related to the vaccine. Another dog had about a day of generally feeling unwell, depression, a lack of appetite and vomiting.

“That was shortly after the vaccine was administered,” Mason says. “The dog was treated with fluids and drugs. Within 24 hours of the bout of illness, the dog was fine.”

The goal is to see if the dogs relapse after receiving the cancer vaccine. With the standard chemotherapy treatment, 90 to 95 percent of dogs that go into remission will relapse within a year. Since beginning the research early last year, about 50 percent of the dogs that received the cancer vaccine following chemotherapy have not relapsed.

“The preliminary results we have at the moment are encouraging,” Mason says.

Originally published on January 10, 2008