Comparative oncology, which integrates the study of naturally occurring cancers seen in veterinary patients to optimize the development of new cancer drugs, has long been a component of One Health. Even if you believe you have a strong grasp on comparative oncology, or if you are not familiar with Chand Khanna, DVM, PhD, DACVIM, don’t stop reading. A new piece has been added to this life-saving puzzle.
Experts from around the world are working to develop commercial relationships between the human and animal health pharmaceutical and biotech sectors to speed development of cancer treatments with a novel approach to comparative oncology and One Health. Their proposal would create additional opportunities for canine clinical trials that ultimately will advance both human and veterinary oncology.
“We hope our recommendations will reposition comparative oncology canine trials as integral and parallel to human development and that this move will create opportunities for stepwise iteration and the improvements in the human cancer drug development path that are increasingly necessary,” Dr. Khanna says.
How drug DISCO came about
Just before the World Small Animal Veterinary Association (WSAVA) 2019 World Congress in Toronto, the association’s One Health Committee held a workshop—led by Dr. Khanna, now at Ethos Veterinary Health and Ethos Discovery, along with William Eward, DVM, MD, orthopedic surgical oncologist at Duke University, and Joelle Fenger, DVM, PhD, DACVIM, assistant professor of oncology and hematology at The Ohio State University College of Veterinary Medicine—aimed at developing a new strategy for enhancing cancer drug development using a One Health approach.
That workshop led to the publication of a report in Annals of Medical and Clinical Oncology earlier this year outlining how new commercial perspectives from closer relationships between the human and animal biotech and pharmaceutical sectors will deliver a “win–win” for both people and dogs in the quest for successful cancer drug development.1 As a means to bring the sectors together, the authors proposed the Development Incentive Strategy using Comparative Oncology (DISCO).
“The field of comparative oncology as part of cancer drug development stands out as a successful example of the One Health approach to medicine, and this new manuscript presents a nuanced and novel strategy to deliver this translational opportunity,” says Michael Lappin, DVM, PhD, DACVIM, chair of WSAVA’s One Health Committee.
dvm360 recently spoke with Dr. Khanna, a driving force behind the initiative, to learn how drug DISCO will enhance drug development and how veterinarians can play a role in advancing this subset of the field. For the past 20 years, Dr. Khanna’s career has been split between practicing as a veterinary oncologist and working as a scientist on drug development in humans through a research program at the National Cancer Institute (NCI). “Because children and dogs get very similar cancers, there was an obvious connection with my work as a researcher and my work as a veterinarian,” he says. “That resulted in me founding the Comparative Oncology Program within the NCI, which is part of the National Institutes of Health.”
The Comparative Oncology Program brought much greater visibility to the field. This clarity highlighted the fact that many of the questions related to a drug’s development simply could not be answered through traditional preclinical models that involved testing on rodents or in human clinical trials. “So, it is not surprising that the drugs with many unanswered questions did not succeed as human drugs,” Dr. Khanna says.
By including his canine patients with cancer in clinical trials, Dr. Khanna has been able to bridge the gap and provide unprecedented insight into human cancer drug development. The data generated from his work are then used in developing human cancer drugs. As a result, life-saving animal health cancer drugs are created as well.
“There are no examples of drugs that are approved for the treatment of cancer in dogs that arose without the intent to develop a human drug,” he explains. “The origin of every drug that has been approved for use in canine cancers came in some way from the development of a human drug.”
Even with increased synchronicity in human and animal oncology research, Dr. Khanna and his colleagues identified a high failure rate associated with cancer drug development for humans and the potential positive impact comparative oncology could have. The drug DISCO initiative was conceptualized to increase adoption through new commercial incentives that would bring human and animal pharmaceutical companies closer. Developing commercial relationships between sectors also facilitates a model for self-funded research.
How drug DISCO works
“The elevator pitch is that we need more chances at bat,” Dr. Khanna explains. “We need more clinical trials that include dogs and then have those same drugs evaluated in humans. This will create a line that can be drawn between the dog response and the human response.”
If all goes according to plan, a human drug company would license its cancer treatment to an animal health drug company. This would provide the human company—which retains the right to develop the drug in humans—with the opportunity to generate revenue by completing research that will help dogs diagnosed with a variety of cancers. The animal health company benefits by receiving access to a successful drug without having to do the upfront research itself.
“It is not as though drug DISCO is a new idea,” Dr. Khanna says. “Right now, these things happen when someone just happens to know people from the animal health company and the human health company and can broker that relationship. We are trying to make this happen more consistently without existing relationships.”
Dr. Khanna hopes that within 5 years these closer collaborations will become more commonplace. One of the biggest hurdles to achieving the streamlined process, however, is that certain aspects of the processes for approving veterinary and human health drugs are unnecessarily siloed. “If we can better align some of these processes, more parts of the approval process for a human drug can be used to simplify a veterinary approval and create efficiency and value for all parties, since part of the approval process will already be done and they won’t have to repeat it all while creating the veterinary counterpart,” he says. There are some parts of the approval process that will need new studies, of course, but the goal is to eliminate redundancy where it is reasonable.
Dr. Khanna says that many requirements of the FDA approval process should be repeated for each species. However, some aspects are unnecessarily repetitive, mainly in the manufacturing approval. He offers a hypothetical example involving the coating of a pill: “If one portion of the approval was to make sure that the coating doesn’t break down when the pill is dropped on the ground, there is no reason to have to prove that for both the human and animal drug because it’s the same ground that the pill hits and everything about the pill is the same," he says. "However, the coating of some pills is broken down differently in an animal than in a human, and that topic would need further veterinary-specific studies and approvals.”
Drug DISCO involves adding commercial incentives, and including the private sector in the equation provides additional opportunities for dogs to be included in treatment trials. “For me, drug DISCO is an opportunity for additional studies and to do so with commercial benefits for both parties,” he said.
Doing your part
How clinical trials help your patients
Clinical research trials, or studies, are aimed at advancing or improving treatment options in all areas of medicine. Veterinary oncology studies may involve existing or new treatments, including chemotherapy, radiation therapy, surgery, and immunotherapy, among others. Many of these trials also provide insight into how the treatments being studied in dogs may be translated to help people with cancer. Clinical trials are conducted largely at colleges of veterinary medicine and at some private specialty referral hospitals.
For some trials, the patient must be brought to the trial location (or sometimes multiple locations), but others involve testing or procedures that can be completed at the primary veterinarian’s office.
It’s important to keep in mind that the safety and/or efficacy of the regimen being studied may have been proven already in laboratory animals, or in healthy dogs or cats, which may make your clients more inclined to participate.
The Flint Animal Cancer Center at Colorado State University in Fort Collins provides a great explanation about the benefits of clinical trials, how trials are conducted, what’s involved for clients, enrollment procedures, and more.2 The AVMA offers a searchable database of veterinary clinical trials in all areas, and the Veterinary Cancer Society provides a comprehensive list of ongoing cancer trials in the United States.
Dr. Khanna hopes that through mutually beneficial research, there will be rapid growth in the number of successful treatments available to treat veterinary patients with cancer.
Many advancements in comparative oncology take place in the laboratory, but all veterinarians can play a pivotal role in improving the field by taking advantage of clinical trials (see How clinical trials help your patients). “If we had every primary care veterinarian in the world realize that there are clinical trials that provide their clients with access to the latest and greatest therapy and encourage them to pursue clinical trials, we would deliver curative outcomes for patients more quickly,” he says.
1. Fenger JM, Eward WC, Hendricks WPD, et al. Delivering innovation to oncology drug development through cancer drug DISCO (Development Incentive Strategy using Comparative Oncology): Perspectives, gaps and solutions. Ann Med Clin Oncol. 2020;3:120. doi: 10.29011/AMCO-120.000120
2. Weishaar K. The ABCs (and DEFs) of clinical trials in veterinary oncology. Colorado State University Flint Cancer Center. Published September 23, 2018. Accessed August 8, 2020. www.csuanimalcancercenter.org/2018/09/13/clinical-trials-veterinary-oncology