Novel Cancer Vaccine Uses Animal's Own Tumor Cells
At Torigen Pharmaceuticals, Inc., veterinarians and immunologists have developed a cancer vaccine that utilizes a patient's own tumor cells.
In Farmington, Connecticut, a team of veterinarians and immunologists are working diligently to distribute and promote a novel treatment: harnessing a patient’s own immune system to fight cancer through a personalized vaccine.
“Each year, about 4 million dogs and 4 million cats in the United States will develop cancer,” said Torigen CEO Ashley Kalinauskas, “and 94% of them are treated at the primary care level with just surgical excision or no therapy at all. But we feel that immunotherapies are really going to lead the way on how cancers are treated. It’s our only avenue for curative intent.”
Torigen’s experimental autologous cancer vaccine works by generating a vaccine from a patient's deactivated tumor cells to stimulate the immune system against specific tumor-associated antigens found on the outside surface of the tumor cells.
“The science behind the technology is the idea that every patient’s tumor is different, and so an immunotherapy of some kind that’s ‘off the shelf’ and intended to treat every tumor is simply at a disadvantage because of the diversity of tumors,” Mark Suckow, DVM, chief scientific officer for Torigen, explained. “The vaccine stimulates the immune system resulting in a cascade of events that culminate in the stimulation of T-lymphocyte cells, which respond and attack the tumor based upon the antigens that we have provided.”
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The vaccines utilize not only specific cancer cells but the tumor-associated tissue that provides a connective network lattice for the tumor to grow and expand. “It is an enormous menu of antigenic targets that we are able to capture and provide,” he explained.
It Started With Sadie
For Dr. Suckow, the origin of Torigen’s technology is very personal. In fact, his own dog Sadie was the first to receive the vaccine.
“I had been working on some cancer models for various things for a number of years,” he explained. But it wasn’t until Sadie was diagnosed with squamous cell carcinoma in 2010 that he brought his work home.
Using a portion of Sadie’s resected tumor, Dr. Suckow created an immunotherapy that was administered to her over the course of a month. Within a week or two, the tumor that remained after excision started to regress and capsulate, eventually disappearing. “My veterinarian said she had never seen anything like it,” Dr. Suckow said.
Following the treatment, Sadie—who was already an adult dog at the time of diagnosis—lived cancer-free for nearly 3 years before dying of natural causes.
Using the Vaccine in Practice
According to Kalinauskas, Torigen has collected data—recently submitted for publication—showing that less than 10% of patients have experienced adverse events with the treatment. And the recorded adverse events were mainly vaccine-associated, such as redness, irritation, lethargy, nodules at the injection site, or mild irritation.
“Those results are really promising because having such a low adverse event profile really allows—even if the therapy is experimental—pet owners and veterinarians to feel like this is something that can be tried,” she said.
To date, the majority of the efficacy and safety data Torigen has collected is centered around solid-based tumors, such as cutaneous and oral tumors (eg, squamous cell fibrosarcoma, melanoma, soft tissue sarcoma), anal sac adenocarcinoma, and transitional cell carcinoma.
“This technology can really work across the board because the goal is to take a patient’s specific tumor and really break it down to the cellular subtype populations, versus actually looking at one cancer over another,” she explained.
If a veterinarian would like one of Torigen’s vaccines created for a patient, the process begins with requesting a tumor collection kit, answering a few questions about the case, and sending a portion of the excised tumor to the Torigen lab. From there, the team prepares the personalized vaccine and sends it back to the veterinary hospital within 72 hours. The veterinarian then administers the treatment by subcutaneous injection on a weekly basis for 3 weeks.
“The veterinary community is really excited about what we’re doing,” Kalinauskas said. “We have a lot of veterinarians who send us tumors for pathology, participate in our ongoing studies, or use our product on a day-to-day basis with their clients.”
Torigen’s autologous cancer vaccine has been commercially available since 2017 and, to date, roughly 250 personalized vaccines have been created for cats and dogs.
One patient that has stuck out to Kalinauskas is a dog from California that was originally undergoing radiation therapy, but it got to the point where that therapy was no longer effective. In fact, the tumor had grown so large that not only was radiation no longer possible, but it would have been very difficult to excise a major portion of the tumor mass. “So even though that tumor was growing, we were only able to get a very small portion [to create the vaccine],” Kalinauskas said. “We’ve done that twice now for that dog, and we can say that after using immunotherapy alone the tumor is no longer growing. It’s really just kind of staying where it is and the dog is still doing great.”
She also recalled a standout case from Torigen’s clinical study where a Beagle presented with a primary osteochondrosarcoma of the liver with a tumor that was more than 1 foot long. “It was a very rare tumor and the published literature was very sparse,” Kalinauskas explained. “But we used the immunotherapy after the tumor was surgically excised, and to date, that tumor has not reappeared and the dog is doing great.”
In addition to offering a treatment modality, the vaccine also provides hope for veterinarians and pet owners. “If seen by a different clinic, that Beagle’s owners might have chosen euthanasia once they heard that the tumor was a foot long. But by utilizing our therapy in combination with a surgical excision we were really able to provide a good life for that dog.”
“Torigen as a company has so much potential and we’re really just on the brink,” Kalinauskas said. “We are about to take on major investments and financing to propel the company forward and it’s our goal to be the leader in canine oncology. And how we’re going to get there is by focusing on immunotherapeutics.”