NEW YORK – With plans in place to launch a urine-based molecular test for bladder cancer detection next month, Vesica Health is also gearing up to validate a second application in post-treatment patient surveillance.
In that vein, European researchers recently published a study in the journal European Urology Open Science concluding that while further validation in larger cohorts is warranted, the company's AssureDx test has the potential to reduce the use of cystoscopies in patients who have had radiation treatment for muscle-invasive bladder cancer.
Vesica Health CEO Christopher Thibodeau said that while the assay was designed for early detection, its developers have long viewed the biomarkers it uses as having potential in other settings.
Although the company has previously presented other data on post-treatment detection, this is the first study that used the final six-gene configuration of the assay, he said.
Vesica's test, which was initially developed by MDx Health, is a PCR assay that detects mutations in the FGFR3, TERT, and HRAS genes, and methylation status of the OTX1, ONECUT2, and TWIST1 genes in a patient's urine sample.
In addition to being the first prospective analysis of the finalized AssureDx assay in the post-treatment setting, the study also addresses what Thibodeau said is a much more aggressive disease in muscle-invasive bladder cancer.
The American Cancer Society estimates that there will be more than 80,000 bladder cancer cases in the US in 2024, including 64,000 non-muscle-invasive tumors and about 10,000 muscle-invasive cases.
"Most of the data we've been generating, or at least the plans that we have to validate the assay for recurrence monitoring, are really in early-stage patients that are treated with intravesical chemotherapy, BCG therapy, or surgical resection of very superficial tumors," Thibodeau said.
Most patients with muscle-invasive tumors currently undergo cystectomy, but there is a lot of interest in treatment de-escalation because of high morbidity, especially in elderly patients, he added. Having a urine-based tool for post-treatment monitoring could help rationalize attempts at chemoradiation.
In the study, investigators from Erasmus University Medical Center recruited patients with nonmetastatic muscle-invasive bladder cancer who underwent (chemo)radiation with curative intent from 2016 to 2020. Prior to post-treatment cystoscopies the team took a urine sample and performed the AssureDx test, comparing results to patient outcomes.
Among 143 total patients the group assayed 503 urine samples. Overall, there were 32 urinary tract recurrences in the cohort, 18 of which had a concomitant urine test available.
Investigators calculated sensitivity, specificity, and negative predictive value of 78 percent, 77 percent, and 99 percent, respectively.
Allowing for a longer time interval between urine test and recurrence, the assay detected an additional ten recurrences — 28 out of the 32. In one patient, for example, the test was positive 6 months prior to the clinically apparent recurrence, but the test performed concomitantly was negative. In another subject, four prior urine tests accurately detected two recurrences, but the fifth test was negative when a third recurrence occurred.
The authors noted that the test accurately detected all three upper tract urothelial recurrences, which are not possible to detect using cystoscopy.
For now, Vesica plans to make the test clinically available next month for its primary application in hematuria patients through what Thibodeau said will be an early-access program with "select clients." The next step will be to submit for Medicare coverage, after which it will push for more widespread commercialization.
If the company is able to further validate its test in the post-treatment setting, having it already established for early detection could be a boon, since many physicians would be interested in both applications, Thibodeau said.
"When we talk about hematuria, there are a few different settings where we would offer the assay," he said. "One would be in primary care, where patients will present with hematuria and then the physician needs to determine whether or not they're at risk for bladder cancer… and then of course, in the urology setting where patients present and cystoscopy is negative, but there's still fear of undetected cancer or upper tract disease."
Urologists tend to manage bladder cancer patients from early diagnosis all the way through advanced stage disease, which is not often the case with other cancer types, Thibodeau added.
"If it does go to metastatic disease, then those patients likely would see a medical oncologist. But we would be primarily focusing on patients with localized disease in the bladder," he said.
Vesica is still working on a seed fundraising round and wrapping up a health economic analysis to demonstrate that the test can provide a positive economic benefit to the healthcare system, Thibodeau said.