A Canine Cancer Vaccine Shows Promising Results

JOHN DANKOSKY: This is Science Friday. I’m John Dankosky.

KATHLEEN DAVIS: And I’m Kathleen Davis. Later in the hour, House Republicans blocked a bill that would expand compensation for folks affected by US nuclear testing and development. So what happens next? And some cephalopod joy.

But, first, dogs are, by far, the most popular pet in the United States. 62 million households in the country have at least one dog. And that’s not too surprising. They are human’s best friends, after all.

Sadly, cancer is the leading cause of death in dogs. When a pet gets sick, it can be devastating for the whole family. So lucky for us, there’s been a new breakthrough in treating canine cancer, and this could lead to benefits for us humans, too.

Joining me to talk about this new vaccine treatment is my guest, Dr. Mark Mamula, professor of medicine at the Yale School of Medicine in New Haven, Connecticut. Welcome to Science Friday.

MARK MAMULA: Thank you very much for having me. Happy to be here and happy to discuss our companion animals and, more importantly, how to keep them potentially healthier, even with diseases like cancer.

KATHLEEN DAVIS: Yeah, so let’s get right into it. How common is canine cancer?

MARK MAMULA: Remarkably, about one in four dogs in their lifetime will get cancer at some point in their life. If the dog or a dog is lucky enough to live to 10 years of age, the overall incidence of cancer goes up to about one in two. About half of all dogs will get cancer.

KATHLEEN DAVIS: I kind of can’t believe how staggering that number is. Why is that so high?

MARK MAMULA: It really is a staggering number. And, of course, it is far higher than incidence of cancers in adult humans. The incidence in dogs has, as several explanations among them, are cancer genes that are predisposed to various breeds that may get vertically or transmitted through interbreeding of dogs. That’s one popular and, in fact, scientifically proven notion. It’s been postulated that the use of herbicides and pesticides on lawns, for example, where dogs continuously have their nose to– literally their nose to the ground, may enhance the prevalence of cancers as well.

KATHLEEN DAVIS: Hmm. OK, so walk me through how this treatment works. It’s a vaccine, right?

MARK MAMULA: Well, it’s an immunotherapy. Yes, it’s two injections of a portion of a protein that is found on the surface of cancer cells. The protein family that is the target of our therapy is known as EGFR or HER2, and we have learned through effective human cancer therapies that these are important proteins on the surface of tumors that activate tumor cells, get them to grow, get them to multiply, and get them to metastasize so all to the benefit of cancer, of course, but to the detriment of the dog or the human.

So our therapy targets immune responses to these surface proteins that, hopefully, find the tumors, and attach to the tumor cell, and block their growth or block their metastasis, and help kill the tumor cell.

KATHLEEN DAVIS: So you’re giving this to dogs that already have a cancer diagnosis versus it being a preventative treatment, right?

MARK MAMULA: That’s correct. This is a therapeutic immunotherapy that, once dogs are diagnosed with certain types of cancers, that they would get this therapy that activates immune responses in a manner somewhat similar to other vaccine responses. For example, humans get vaccinated to a number of pathogens. This is much like that with the difference being that the immune response targets the tumor or proteins on the tumor.

KATHLEEN DAVIS: So what kind of cancer is this meant for?

MARK MAMULA: This is meant for a wide variety, actually, of tumors in dogs that express these EGFR and HER2 proteins. And they include the more common cancers in dogs, including osteosarcoma and hemangiosarcoma. Other cancers are included as well that express these proteins, and those can anal sac carcinoma, certain types of bladder CANCERS certain types of lung cancers, soft tissue sarcomas, of course, breast cancer, which is found in dogs as well, as well as colon cancer. So really a large number of solid tumors that are found in dogs do express these tumor proteins.

KATHLEEN DAVIS: What kind of efficacy rates are you finding in the trials that you’ve done so far?

MARK MAMULA: Well, we’ve had recent trials ongoing for about the past year and a half, and those were preceded by an open label trial about three or four years ago now, actually. And we found, interestingly, that dogs that get osteosarcoma and receive our therapy actually have a increased survival rate compared to standard of care, typical standard of care for dogs with osteosarcoma, which is a bone cancer primarily in the large bones of the leg.

Typical therapy for dogs that have this kind of cancer is amputation of the infected limb. Sometimes radiation can be used on the affected limb, but, most often, it’s amputation as a surgical intervention along with chemotherapy. And, when we add our immunotherapy to that regimen, it almost doubles the 12-month survival of dogs with osteosarcoma.

So, with standard of care, the survival of dogs with osteosarcoma is fairly disappointing. Only about 35% or 40% of dogs will survive 12 months. And, as I mentioned, if one adds our immunotherapy to that classical treatment protocol, we get almost 60%, 65% of survival after 12 months and a number of dogs that have lived two, three or four years after receiving our therapy.

KATHLEEN DAVIS: So that’s a huge benefit. That’s really significant.

MARK MAMULA: Significant, yeah, significant advances, particularly when, of course, the longevity of dogs, which is anywhere from 8 to 12 or 15 years, the fact that their lives are so short to begin with, getting a benefit of one or two or three years is a very significant benefit to the total lifetime in a dog, of course.

KATHLEEN DAVIS: So I’m sure that there are people who are listening to this who are really interested in getting this treatment for their dogs. Is that even possible for people to get their hands on this at this point? Is there a timeline for that?

MARK MAMULA: Well, we have clinical trials ongoing, and the sites that are utilized using our therapy or performing our clinical trials, there are ten, probably soon to be 11 sites in this country, one in Canada. One can find the sites that are performing this therapy, and that can be found on a website called TheraJan, T-H-E-R-A-J-A-N, .com.

In full disclosure, this is a company that will ultimately manage this therapy for canine cancers. Nonetheless, it will list all of the sites that one can find this therapy. You can contact the clinics directly for details about qualifying for the clinical trial. At the moment, the clinical trial is for use in osteosarcoma, hemangiosarcoma, and bladder cancer, or what’s known as transitional cell carcinoma.

So, again, call the clinics directly. And they’ll try and get you in and give you all the qualification details. And it should be just as easy as that.

KATHLEEN DAVIS: So, obviously, this has been really promising for canine cancer, but could this eventually make the jump to a better treatment for human cancer?

MARK MAMULA: Another great question. Yes, we actually designed the study with translational applications in mind and, of course, the translational application to treating human cancers. We have not yet started clinical trials in human cancers, but, hopefully, in the coming few years, I would guess we would initiate similar trials in humans.

KATHLEEN DAVIS: And for the same types of cancer, bone cancer, bladder cancer.

MARK MAMULA: Yes, humans get slightly different types of cancers that express the proteins that we target, but, notably, EGFR and hER2L On human cancers include gastrointestinal cancers and some breast cancers, again, some lung cancers. Regarding the, canine therapy, we are seeking USDA approval for conditional licensing that will allow us, hopefully, widespread distribution of this therapy to locations all around the country.

We’ll probably start with veterinary oncology offices. But, at the moment, the availability is restricted to the clinical trial sites.

KATHLEEN DAVIS: So one thing that I’ve gleaned from talking to you today is that you clearly love dogs. So, removing yourself from your role as a researcher on this, how exciting is this for the dog lovers out there?

MARK MAMULA: Oh my gosh. Well, you’re talking to one dog lover.

[LAUGHTER]

I have two golden retrievers, one that’s 11 and 1/2 years old, so cancer is not far from my thought process with my own dogs. In fact, one motivation for our study in studies in treating dog cancers was, in fact, from my own family. We had a Labrador retriever that passed away from an inoperable cancer about 11 or 12 years or so ago.

KATHLEEN DAVIS: Mmm.

MARK MAMULA: So I do know how important dogs are as companion animals and families, and many or most families, of course, treat their dogs like they are family, as we did. And I actually was on the side of the family with a dog with cancer as well as now on the treatment side of cancers in our dogs.

KATHLEEN DAVIS: Well, we wish you the best of luck with this work. That is all the time that we have for now. I’d like to Thank my guest, Dr. Mark Mamula, professor of medicine at the Yale School of Medicine in New Haven, Connecticut. Thank you so much for joining us.

MARK MAMULA: Thank you for having me. It was a pleasure.

Copyright © 2024 Science Friday Initiative. All rights reserved. Science Friday transcripts are produced on a tight deadline by 3Play Media. Fidelity to the original aired/published audio or video file might vary, and text might be updated or amended in the future. For the authoritative record of Science Friday’s programming, please visit the original aired/published recording. For terms of use and more information, visit our policies pages at http://www.sciencefriday.com/about/policies/