to give the drug so you can get biologic activity.” Ohio State is now doing a second study with Synta to look more closely at dosing regimens, London says.
Proia says Synta plans to measure dozens of variables in the dogs, ranging from how specific genetic mutations affect their response to how long the drug continues working in the body after it’s infused. Drug companies can do experiments like that in lab mice—say by taking tumor samples from humans and injecting them into the rodents—but dogs offers a more realistic model, Proia says. “I cannot think of a better model than a dog that comes into the clinic with an equivalent disease,” Proia says. “[London’s] animals really can mimic what’s occurring in human patients.”
Synta is currently studying ganetespib in two lung cancer trials and a breast cancer trial in people, with hopes of moving into the pivotal trials that are required for FDA approval by the end of the year. As a small company, Synta does not have the resources to pursue a veterinary approval at the same time, though the insights the company is gaining from the dog trials have been invaluable, Proia says. “If we see very clearly [in the dogs] that one dosing schedule stands out, we’ll think about whether we should implement it in our patients,” he says. “There may be different dosing strategies for different tumor types. That’s really important.”
Szalay of San Diego’s Genelux says that although his company is also strapped for resources, he is considering several options for pursuing the veterinary market. “We may license [V-VET1] or co-develop it with a large veterinary hospital,” he says.
The use of pet dogs in early research is bound to intensify, as the FDA becomes more comfortable with the role of comparative oncology in drug development. Both Ogilvie and London report that some companies they’re working with have included data from trials in pet dogs in packages they’ve submitted to the FDA for approval to start human trials—even when the drug being tested in dogs is different than the human version. “The FDA values real-life models,” London says.
As for Chance, the first dog to enroll in Genelux’s trial, he has had two injections of the experimental drug so far and is not showing any major side effects, Willcut says. And Ogilvie says he’s constantly trading notes on the Genelux trial and others he’s working on with the oncologists at UCSD’s Moores Cancer Center. “I’ll get an e-mail or a call every week asking what I’ve found,” he says. “They want to know how they can use the information to benefit people.”
“First and foremost we’re working for the animals,” Ogilvie adds. “But our objective is to take these discoveries and bring them to people with cancer.”
