COLUMBUS, Ohio (Circa) -- During the summer of 2017, Bob the horse began experiencing breathing problems and was later diagnosed with chronic lymphocytic leukemia (CLL).
CLL is a blood cancer that's rare in horses, but relatively common among humans, according to a press release from The Ohio State University Comprehensive Cancer Center.
"He was treated wih a chemotherapy regimen and he did fairly well with that for awhile, but he relapsed," explained Bonnie Harrington, a doctor of veterinary medicine who is working on Bob's case.
When Bob relapsed, his primary care veterinarian turned to Dr. John Byrd, a hematologist who specializes in treating the same condition in humans.
"We have access to some novel therapeutics that are really safe in humans and have revolutionized the treatment for them," Harrington said. "So we were able to procure some of these medications at a really reduced cost so that we could administer them to Bob."
So far Byrd and his team, which consists of human and animal cancer specialists, have been working with Bob since the beginning of April. Harrington said Bob has been on the drug, Ibrutinib, for about three weeks now.
"One of the biggest challenges with giving him this medication is that -- so we have a dose and a safety, a therapeutic index established in people, but since horses metabolize things a little bit different than in people, we don't know exactly how much to give him," she said.
So far, Bob hasn't shown signs of improvement, but remains stable. Harrington said that's likely due to the fact that they are still trying to figure out the right dose for a horse.
She added that once the team escalates Bob's dose, they expect to see a better response.
Although this drug is well-established in terms of human use, this is the very first time it's being used on a horse. Harrington said if Bob improves, it could make the treatment more cost effective.
"There's a chance that some drug company will develop this and market this toward veterinary use and make it a little more cost efficient so we would be able to use it clinically a little more often than we can now," Harrington said.
Bob's owner told The Ohio State University Comprehensive Cancer Center that she sees this as "extremely important" research that could be beneficial to both pets and people.