NEW YORK – Encouraged by recent changes in professional guidelines and reimbursement policies, diagnostics firms are expecting an adoption boost for prostate cancer risk tests, some of which have been on the market for nearly a decade without achieving widespread use.
Companies in the space include Myriad Genetics, which markets the Prolaris assay; MDxHealth, which recently acquired the Oncotype DX Genomic Prostate Score from Exact Sciences; and Veracyte, whose urology portfolio came via the acquisition of Decipher Biosciences.
MDxHealth's GPS assay was originally developed by Genomic Health, whose analogous Oncotype DX breast cancer test has been ubiquitous in the clinic for several years, alongside competing assays from Myriad, Veracyte, Agendia, and others.
Used to assess gene expression patterns in tumor samples from early-stage breast cancer patients, the assays help guide oncologists' decision-making regarding next steps.
Although similar in scientific design and clinical intent, the prostate-oriented siblings of these tests have lagged significantly behind.
That could be poised to change, though, buoyed by what test makers say are significant shifts in attitude and attention among the urology community. According to MDxHealth CEO Michael McGarrity, prostate cancer prognostic testing is solidly headed for the standard of care.
"I think we're exactly where breast cancer was when it went over that hurdle," he said.
A few things herald this shift, including the fact that these tests are now described in the National Comprehensive Cancer Network's professional guidelines.
The NCCN's 2020 update recommended biomarker testing for prostate cancer patients with unfavorable intermediate or high risk for aggressive disease using either Myriad's Prolaris, or the Decipher test, now marketed by Veracyte. For patients with low-risk or favorable intermediate-risk disease and life expectancy of 10 years or longer, the update endorsed Decipher, Prolaris, Oncotype DX Prostate, and Dianon Pathology's ProMark.
In May 2022, the American Urological Association also updated its guidelines on the management of patients with localized early-stage prostate cancer, endorsing selective use of genomic biomarker tests.
Although the AUA didn't recommend routine testing, it did state that clinicians may use tissue-based genomic biomarkers when added risk-stratification could alter their clinical decision-making.
With guideline inclusion, McGarrity said that recognition of the Oncotype GPS assay has spread from what used to be mainly key opinion leaders to a broader community of doctors and non-teaching institutions.
This awareness is also spreading to patients themselves, he added. "We obviously are not doing … direct to consumer, but I would tell you that if you've got a friend or family member that is being worked up for prostate cancer, this is the path you want to take," he said. "And I think that is becoming [clearer] as patients become more and more educated," he said.
"That's another key point that usually tips the market adoption curve … to broad acceptance as standard of care, and we're moving into that, which we think will be evident as we go forward."
Veracyte's Tina Nova, who directs the company's urologic cancer business, attributed the slower advance of prostate cancer prognostics compared to equivalent breast cancer tests to the biological differences between these tumors.
"Prostate is a very slow-growing cancer, so to get the clinical trials that give you enough of an endpoint … is really what took so long," she said. According to Nova, it took years to get access to the initial data to validate Decipher.
"The good news is that prostate cancer is slow growing," Nova added. "The bad news is that it's slow growing. It depends how you look at it."
The clinical niches are also very different. By the time breast cancer prognostic tests are being considered, patients are under the care of an oncologist. In prostate cancer, they are usually still being seen by a urologist.
Another factor adding to the drag on evidence generation, Nova added, has been the difference in the sociological milieu of prostate cancer compared to breast cancer.
"Historically it has been difficult for men to admit that they had prostate cancer and to participate in trials. Women in breast cancer, they'll say, sure I'll be part of the trial, and are very open about it. But it was actually very difficult to even enroll [in prostate cancer]," she said.
The evidence dam seems to be breaking, at least for Decipher. Among recent data, Veracyte has amassed additional evidence that its test can personalize treatment decisions for individuals with clinically high-risk prostate cancer and has forayed into molecular subtyping using the whole-transcriptome data collected for each tested patient in its Decipher GRID report.
But adoption challenges remain, Nova said. For example, large numbers of prostate cancer patients still aren't getting any molecular testing, even tumor genomic profiling, despite these tools becoming ubiquitous in other cancer types. This makes pushing prognostic testing forward even harder.
Terry White, Myriad Genetics' general manager of urology, echoed this in an email, saying that his firm estimates that only about 25 percent of localized prostate cancer patients get a biomarker test and even fewer patients who meet guidelines receive a germline or somatic test, "so there is still a significant number of men who should be tested."
"Every man with prostate cancer deserves a better answer than what they are currently getting," he added.
He added that the inclusion of tumor prognostic and germline testing has also been an important step as Medicare and other managed care organizations have expanded coverage as a result.
All three of these tests are covered by Medicare, though with some differences. The Oncotype DX GPS for example is limited to low-risk and favorable intermediate-risk prostate cancer, while Decipher is reimbursed in high-risk disease, as well.
McGarrity said that MDxHealth believes it can gain similar expanded coverage and guideline recognition for the GPS test based on solid foundational data that came over with the Exact acquisition.
In recent private payor news, UnitedHealthcare said in February that it has added coverage for prostate cancer gene expression profiling, naming the Oncotype DX assay as proven and medically necessary for patients with biopsy-proven, untreated, localized adenocarcinoma as long as the ordering urologist or oncologists intends to use the results to aid their treatment decision-making.
The payor said it will also cover the use of the Decipher Prostate classifier post-prostatectomy in patients whose tumors show adverse features or who have persistent or recurrent elevated PSA.
Overall, all three firms identified progress in the last year or so toward much more widespread adoption.
White echoed McGarrity saying that Myriad hopes to soon see a similar trajectory for Prolaris as the field saw for prognostic tests in breast and ovarian cancers nearly a decade ago. In Q4 2022, the company saw double-digit year-over-year revenue growth for the test, he said.
Veracyte didn't break down its earnings by test product but reported that its own fourth quarter 2022 test revenues were up 32 percent, with Decipher as one of the major drivers.