Cancer Kills Millions of Dogs. Will Immunotherapy Prolong Their Lives?

Immunotherapy has transformed cancer treatment. It tinkers with the immune system to attack malignancies that have evaded the body’s natural defenses. This advance offers an alternative to treating cancer with surgery or chemotherapy and radiation, which can attack healthy tissue and cause extreme side effects.

The treatment is not only scientifically complex but also expensive. The investment of money and time makes sense when it comes to saving humans. But what about when it comes to dogs?

Dr. Hans Klingemann has worked on and researched cancer immunotherapy for decades, leading departments at Rush University Medical Center in Chicago and Tufts Medical Center in Boston. Now, he’s the chief science officer for cellular products at ImmunityBio, which develops immunotherapy drugs for people. But he has also written two papers exploring whether the new treatments might someday prolong canine lives.

The interview below has been condensed and edited for clarity.

What interests you about immunotherapy and dogs?

I love dogs. I have dogs: Sophie and Maximilian. They are each around 18 pounds, a mix of a bichon and a Cavalier spaniel.

Did they develop cancer?

Fortunately, they haven’t gotten cancer…. yet. But when dogs get older, many get cancer. Are there some benefits from immunotherapy? Could we make life easier, the remaining life, for the dog and the owner?

In most cases, dogs actually get chemotherapy treatments. We don’t know how much these treatments affect the quality of the remaining life, and, in most cases, it is not even very clear how effective these treatments are.

Your first paper on the subject found significant obstacles in the development of immunotherapy treatment for dogs. Can you describe them?

Drug companies are very financially conscientious. They have not really developed monoclonal antibodies or other more targeted immuno-treatments for dogs. It doesn’t make sense financially for them. For example, an antibody treatment for a dog could easily cost thousands of dollars, and no insurance company would pay for it, and — with the occasional exception, of course — no dog owner will. So, there is really no market for the big drug companies.

At the time, was there evidence these drugs worked in dogs?

Vet research centers would treat 12 to 15 dogs with Drug X, but there was no real comparison. How would they have done with another drug, like Drug Y? These comparisons offer the most controlled studies, which have not been done systematically in dogs. Also, cancer risk is breed-dependent. The risk depends on the breed and the age of the dog. It is difficult to get, let’s say, 20 dogs for one breed. So it’s difficult to get clean data.

And in humans, we can gauge benefit versus harm because a doctor can ask us how we’re feeling. But you can’t ask dogs. They just lie in the corner and don’t like what we are doing.

You also raised the point in your first paper that human drugs may not work for dogs because our genetics are different.

Dogs and humans have an 80 percent to 85 percent genetic homology. Although that sounds pretty good, it is not sufficient to just give a dog an immunotherapy that has been shown to work in humans.

Efforts are underway to get an assessment for dogs in terms of how well they take immunotherapy and cancer treatment in general. Some centers are trying to get a scale for how an animal is feeling and response rate to treatment.

One recent study tested whether a human immune protein can be given by inhalation to dogs who have extensive metastatic disease from melanoma or bone cancer in their lungs. It showed promising results; they define the dose which is tolerated in dogs, showing encouraging survival times in treated dogs, and good tolerability. It will pave the way for future studies using human immune-active cytokines in dogs.

But there still has not been a lot of push to develop novel immunotherapies for dogs. There has been little progress, a stagnation. It’s a little bit harsh, but that’s basically right. I would hope that in a few years, we can have more targeted immune-based treatments for our dogs — but they have to be affordable.

Did this realization force you to rethink the eventual death of your dogs?

What I’m wondering for now is how we can make the remaining life after a cancer diagnosis for the dog (and the owner) more tolerable with palliative treatment options that prolong life but also maintain the quality of the remaining life. That’s all I would ask for, and I know that many dog owners feel the same.

How are your dogs doing?

Sophie is 3. Maximilian is 13; he had a walk on the beach today. He’s not sick with anything. He just gets tired because he’s older and he sleeps a lot. But I completely understand that.