A Tribute to PetDx: Pioneers in Veterinary Oncology
As veterinarians, scientists, and lovers of companion animals, we often lament the slow pace of progress in developing new tools to improve health and to diagnose and treat disease in our pets, particularly as we look with frustration and envy at rapid advances happening in human medicine. Our field is overflowing with brilliant, passionate, and selfless clinicians, researchers, pet owners, and entrepreneurs. And we have no shortage of new ideas either borrowed from human medicine or generated de novo in veterinary medicine.
So why aren’t we making more progress in veterinary oncology?
The answer is that medical innovation requires not just dedication and steady science, but it also requires significant resources (people, money, infrastructure), disruptive ideas, development of new markets, and education and sometimes even redirection of an already overburdened and under-resourced veterinary healthcare system. And it requires the bold pioneers willing to take big risks to bring new products to market. The team at PetDx was just such a set of trailblazers who uniquely brought not just ground-breaking genomic science and technology to market that was modeled on developments in human oncology, but they also brought substantial new investment, rigorous research, and expansive educational campaigns to animal health that have left an indelible mark on the field.
Having also experienced first-hand the challenges of bringing new, disruptive genomic science to clinical practice through our startup, Vidium Animal Health, as we sought to transform pet cancer care by offering genomic diagnostics to guide veterinarians in the management of dogs with cancer, we (Derick Whitley and Will Hendricks) have a unique perspective on and appreciation for the pioneering accomplishments of PetDx. Vidium and PetDx were aligned on a mission and vision to bring about a revolution in veterinary oncology across the care continuum – from early detection to cancer treatment and monitoring – based on the power of genomic medicine. We saw ourselves as fellow travelers on the road to bringing about substantive change in our domain, with mutual commitment to scientific integrity and transparency. PetDx closed its commercial operations in early 2024, in developments all too common in the animal health startup world. However, their pioneering work in liquid biopsy-based pet cancer screening has already reshaped the field of veterinary diagnostics. The people and their work have also left a legacy that will continue to be woven into the story of veterinary oncology.
This letter is a tribute that seeks to celebrate PetDx’s accomplishments and encourage all inventors, researchers, veterinarians, and investors with a passion for animal health to take similar bold steps to accelerate progress in veterinary medicine.
Founding PetDX
PetDx was founded in 2019 by Daniel Grosu, Andi Flory, Ilya Chorny, Art Polk, and Lisa McLennan, with additional co-founders that soon followed including Lauren Holtvoigt, Adam Woloszyn, Jason Chibuk, Jason Loftis, Dana Tsui, and Kalle Marsal. Grosu’s vision for PetDx was inspired by the loss of his own dog, Poppy, to an aggressive cancer diagnosis. His frustration with the limited options he faced to diagnose and treat Poppy’s cancer, and his first-hand knowledge of the innovation in genomic diagnostic technology that was upending human oncology through his own leadership in that industry showed him the great need and opportunity in veterinary diagnostics. Based in San Diego, an impressive team spanning genomic technology research, product development, commercialization, and clinical expertise from human and veterinary oncology was assembled. This team aimed to revolutionize canine cancer diagnostics by enabling early cancer diagnosis and intervention in older and at-risk dogs with an affordable, high-performing, non-invasive annual screening test. Unlike us, our furry friends can’t tell us when they are feeling a little off, and many cancer cases in pets are not identified until they are in advanced stages, often after metastasis has occurred, making treatment more challenging. The core technology was based on the concept of “liquid biopsy”, an approach to non-invasive diagnostics increasingly being studied and even clinically utilized in human oncology. Discoveries at the turn of the millennium had shown that cancer cells shed their DNA into the circulation. This circulating tumor DNA, although present in the blood at low abundance, could nonetheless be detected by emerging ultra-sensitive DNA sequencing technology. Detection of this tumor-specific DNA in circulation was highly specific for cancer cases versus patients without cancer. This cutting-edge genomic sequencing technology was rapidly evolving in its performance and clinical viability, but had not yet been extensively explored in canine cancers. Though some early preclinical research suggested similar patterns of cancer DNA shedding into canine circulation, before the work of the PetDx team, little progress had yet been made to bring this technology to market based on robust preclinical and clinical research. Thus, at the intersection of their recognition of a great unmet clinical need, their deep first-hand knowledge of veterinary oncology, and their world-class team of genomics scientists, PetDx developed a novel genomic diagnostic assay that analyzed circulating cell-free DNA (cfDNA) in whole blood from dogs to identify low-abundance tumor-derived genomic alterations very specifically enriched in cancer cases.
Launching OncoK9
By 2021 we’d heard quite a bit about PetDx and its upcoming launch. We knew the company was making progress, but nobody expected the energy with which they exploded onto the scene of veterinary diagnostics. After a Series A raise of $10 million in 2020, the company’s high-caliber scientific team launched its flagship test, OncoK9, in 2021 as a multi-cancer, early detection (MCED) liquid biopsy assay that was the first of its kind in veterinary medicine and, in fact, only the second MCED test launched in ANY species. The test was launched on the foundation of rigorous science, including the largest clinical validation study ever performed for a cancer diagnostic in pets, alongside a robust ongoing clinical research program. In parallel, the company closed an impressive $62 million Series B in 2021. Remarkably, much of this investment came from sources that did not traditionally invest in animal health and thus PetDx brought a much-needed infusion of new capital from new sources to a space highly in need of new resources. Early on, PetDx also secured key distribution partnerships with Petco, Idexx, and Antech, expanding its footprint and ensuring multiple avenues for sales of this novel diagnostic. These kinds of partnerships are uncommon, but are highly desired among startups. It’s even more uncommon for these large diagnostic laboratories to dedicate web pages and CE events toward promoting a product not their own, something that occurred routinely with PetDx as a result of these partnerships and indicated the significant buy-in of the diagnostics industry.
Educating the World
Meanwhile, PetDx also launched an extensive education and marketing campaign geared toward informing the veterinary community about this new non-invasive opportunity to identify canine cancer patients earlier. From 2021 until the doors were closed in 2024, Dr. Andi Flory was a prominent figure at conferences, on social media, on podcasts, in videos, and in the news. Her speaking and education style was calm and methodical, exhibiting confidence and great poise as she took on the large task of educating the veterinary world about this new technology and application. It wasn’t uncommon at large conferences for Dr. Flory and other members of the team to be slotted for three or more speaking sessions within packed auditoriums, indicating that the community obviously had an appetite for this kind of content and wanted to learn more. In 2022, Dr. Flory was honored with the oncology award at the Veterinary Heroes™ gala during the Fetch dvm360® conference in Kansas City, Missouri. There’s no doubt that Dr. Flory was one of the most recognizable and appreciated speakers in veterinary medicine during the 2021-2024 years, doing much to not only bolster the reputation and name recognition of PetDx, but to also seed a deeper understanding and appreciation of the power and value of genomic diagnostics much more broadly.
Advancing Science
PetDx did as much to advance canine cancer research as it did to develop an emerging technology market. Their key scientific accomplishments across two primary clinical research programs and satellite studies employing the OncoK9 test were extensively documented across numerous publications and were part of a constant presence at scientific and clinical conferences. Notable advances included:
- The CANDiD Study: The CANDiD study was a landmark achievement. With >1,700 client-owned dogs, it was the largest canine cancer clinical trial to date, providing a solid foundation for evaluating the performance of the OncoK9 assay. The specificity was determined to be 98.5%, with a sensitivity of 55% across all cancer types. The sensitivity was greater than 85% for three of the most aggressive cancers in dogs: lymphoma, hemangiosarcoma, and osteosarcoma. OncoK9 identified 30 distinct cancer types, validating the use of PetDx’s NGS-based liquid biopsy assay as a non-invasive multi-cancer early detection test
- CLASSIC Study: Building on CANDiD, the CLASSIC (Cancer Lifetime Assessment Screening Study in Canines) was a prospective longitudinal cancer screening study in which enrolled dogs were screened for cancer with physical exams and NGS-based liquid biopsy testing on a serial basis over their lifetime. So beyond observational measurement of OncoK9’s performance in CANDiD, PetDx also gathered one of the first datasets that was able to comprehensively assess cancer incidence by leveraging multiple types of evaluation. The goal was also to assess the benefits of using the OncoK9 liquid biopsy test as a cancer screening tool in a clinical setting and to demonstrate test performance for cancer detection, including preclinical detection. The study included 726 presumably cancer-free client-owned dogs across 24 sites. Over a mean on-study duration of 422 days, 51 dogs (12%) were newly diagnosed with cancer. NGS-based liquid biopsy doubled the overall number of cancer cases detected (from 25 to 51), and the detection rate of preclinical cancer increased 4.5-fold, from 12% to 55%, by combining routine care with OncoK9 testing. Critically, this study also showed key evidence to support the value of multi-cancer screening in general.
- Peer-Reviewed Publications: PetDx was prolific in publishing research. Beginning with reviews published in 2021 (PMC8021921, PMC8297996) and followed by the CANDiD (PMC9041869) and CLASSIC studies and their satellite analyses (PMC9889684, PMC9891508, 10.2460/javma.22.11.0526)) as well as a compelling assessment of age-related somatic alterations in canine blood (PMC10384417) and, most recently, analysis of the use of OncoK9 for cancer monitoring and residual disease detection (10.2460/ajvr.23.07.0163) as well as a study assessing a new, lower-cost screening strategy (10.2460/javma.23.10.0564).
Their work has left an indelible mark on the field of canine oncology in rapidly accelerating our understanding of dog cancer incidence, of its molecular underpinnings, and of the great utility of highly sensitive and specific genomic screening, diagnostic, and monitoring tests. It is safe to say that all future advances in these domains will stand on the shoulders of this remarkable team.
In January 2023, PetDx brought in a new CEO, Dr. Alejandro Bernal, an experienced executive leader in animal health, to lead the company through its next phase. In the fall of 2023 there was talk of an upcoming new liquid biopsy test that would be much cheaper and in line with price sensitivities in the market, a test that did end up launching in February 2024 as “OncoK9 Screen”. However, in parallel there were concerning rumors going around that PetDx was seeking an acquisition and that the organization was experiencing financial challenges. Indeed, shortly after the launch of OncoK9 screen, in March 2024, PetDx announced to customers it was no longer accepting submissions, and that commercial operations were shut down.
Creating a Legacy
PetDx closed its commercial operations in early 2024, and the authors are not informed as to the fate of the data, IP, and other assets accumulated over the years. Despite these events PetDx’s contributions have served to educate the veterinary community broadly as to the use of liquid biopsies for the purposes of early cancer detection. It’s not an understatement to say that PetDx brought over the relatively unknown and new term and concept of “liquid biopsy” to become a household term now recognized and understood by most veterinarians as a result of their massive education campaign. Their scientific approach and commitment to innovation have established new standards in the field, ensuring that their legacy will continue to influence and inspire.
- Setting the Stage for Future Advancements: PetDx’s groundbreaking work in liquid biopsy technology for dogs has opened the door for future research and development in the field. Its successful application of cfDNA analysis in canines has proven the feasibility and utility of this technology, paving the way for other companies and researchers to build upon their foundation.
- Industry Influence: PetDx’s efforts have significantly influenced the veterinary diagnostics industry. By demonstrating the effectiveness of liquid biopsy for early cancer detection in dogs, they have encouraged other companies to explore similar technologies. The high specificity and sensitivity rates achieved by OncoK9 have set a benchmark for future assays, ensuring that new developments in this field will strive to meet or exceed these standards.
- Educational Impact: Through their extensive marketing and continuing education campaigns, PetDx has raised awareness about the importance of early cancer detection in dogs. Their presence at veterinary conferences, CE events, and in various media has educated countless veterinarians and pet owners about the benefits of liquid biopsy, fostering a culture of early detection and proactive care.
- Inspiration for Future Innovations: PetDx’s journey has inspired other startups and established companies alike to innovate and push the boundaries of what is possible in veterinary diagnostics. Their commitment to rigorous science, coupled with their ability to secure significant funding and strategic partnerships, serves as a model for future ventures in this space.
Conclusion
PetDx’s closure was unfortunate for the entire veterinary community. One might conclude that they were too early or too bold, that investing in oncology or diagnostics is a bad idea, or that the market isn’t interested in advancing cancer diagnostics and treatment in animals. Were these investors wrong to be excited about this application? Should investors stay away from the oncology space? We don’t think so, and instead emphatically declare that the field is ready for meaningful change in the oncology paradigm. At this time there are a number of companies bringing innovative approaches to cancer screening via liquid biopsy testing. Although PetDx did not succeed commercially, their legacy remains. It is out of admiration for their bold and science-based mission to change canine cancer for the better that we write this tribute. It is with hope that we encourage others to step into this space and build on the foundation that PetDx built.
