This new gel can help kill cancerous tumors on animals
A promising new cancer treatment developed in the Tri-Cities has been used on its first commercial patient — a long-haired cat named Drake.
Vivos Inc. of Richland has spent three years developing and testing a cancer-killing gel after licensing the technology from Battelle, which developed it at Pacific Northwest National Laboratory in Richland.
So far, it is being used at the company’s first pilot clinic for treating dogs and cats.
Starting this summer the technology has been offered at one vet clinic in the nation — Vista Veterinary Hospital in Kennewick.
But the startup company’s goal is to eventually offer the treatment for human patients, injecting a high dose of radiation directly into a tumor without damage to healthy tissue.
“The technique we developed is exactly what we will use in humans — identical,” said Michael Korenko, Vivos chief executive officer.
Vivos is starting with the less costly development of treatment for tumors in animals, which could help finance its development of treatment for people.
The company sees a large potential market, with cancer killing about 32 percent of cats and 50 percent of dogs over age 10 in the United States.
Burgess Bauder, a veterinarian in Sitka, Alaska, researched options for his pet Drake when the cat’s spindle cell sarcoma tumor reappeared.
The cancer had been treated previously with external beam radiation, in which a beam of radiation is sent through the skin to kill cancer cells. It’s a treatment commonly used for human cancers.
High radiation dose
Drake’s cancer was on his face, growing into his nose near his eye. Surgery was not an option.
Instead, Bauder picked Vivos’ IsoPet to treat it, knowing it could deliver a much higher dose of precisely placed radiation than Drake had previously received.
“It is an elegantly simple procedure,” Korenko said.
The radioactive gel that is the basis of IsoPet is a liquid that can be injected into a solid tumor. But it quickly turns into a gel at body temperature, which keeps it where it was placed.
It includes a polymer and microspheres of radioactive yttrium 90 too small to be seen by humans.
The polymer binds the microspheres in place as the yttrium 90 bombards the cancer with powerful beta radiation that travels only a short distance.
Little of the radiation reaches nearby tissue, unlike external beam radiation which travels through skin and other healthy tissue to kill cancer.
Multiple injections are made to ensure uniform distribution so all cancer cells receive a high radiation dose, said Darrell Fisher, now a Washington State University research professor, who worked on the technology at PNNL.
“So you put it there, and it stays there. The only thing you irradiate is the tumor,” he said.
For Drake, that meant treatment with a radiation dose that was about eight-times greater than the standard external beam radiation dose.
Injecting the solution at multiple points in Drake’s tumor took Veterinarian Michelle Meyer about 25 minutes.
After the cat recovered from anesthesia and was checked to make sure there was no radioactive contamination, he was released the same day, she said.
No sign of dog’s tumor
Half of the radioactivity of yttrium decays every 2.7 days, so a substantial dose of radiation continued to kill Drake’s cancer cells for about 10 days.
At about three weeks after treatment Drake’s tumor has already shrunk in size by about 80 percent, Bauder told Korenko last week.
The procedure also was done on cats during research at Washington State University and then was tested on four dogs at the University of Missouri. Meyer traveled to Missouri to learn the technology.
One dog, a miniature pinscher named Moose, previously had a soft tissue sarcoma removed from his front leg but not all of the tumor was removed and it started growing back.
His owners posted on social media that they were considering options such as amputation of the leg, 21 days of radiation followed by chemotherapy or doing nothing before they heard about IsoPet trials being done in Missouri.
Moose was treated in October and his owners posted Friday on the dog’s Facebook page.
“Hallelujah!!! No visible soft tissue sarcoma tumors! Final official report is in from 1 year since diagnosis!”
Moose, who is back to chasing squirrels, has clear lymph nodes and perfect blood work, his owners reported.
Testing for human cancers
The treatment now offered commercially for cats and dogs is expensive. It compares with the $8,000 to $12,000 cost of treating an animal with external beam radiation.
Vivos is working to bring the cost down.
One of the chief cost drivers is the production by hand a dose at a time of both the hydrogel and radioactive microspheres that are mixed together to make the treatment solution.
Vivos believes that treating several cats and dogs at once will start bringing the production cost down in the short term, before more efficient production is available.
After learning from the treatments at Vista Veterinary Hospital, Vivos plans to open regional veterinary centers around the country. There also has been interest from horse owners.
Pre-clinical testing for people already has begun with the work at the University of Missouri.
Vivos would like begin human therapy after Food and Drug Administration approval in 2023.
The first application could be in advanced basal cell and squamous cell skin cancers, Korenko said.
Medical consultants to the company have said the technology called RadioGel for human use could also have advantages over existing therapies for a wide range of other cancers.
They include cancers in the liver, pancreas, bladder, head, and neck and spine, plus certain breast, thyroid and brain cancers.
Pet owners interested in treatment now may fill out an application online at radiogel.com under IsoPet.