NEW YORK – Esophageal cancer diagnostics firm Previse, formerly known as Capsulomics, has moved forward with its commercialization of a test for Barrett's esophagus while it continues developing its esophageal cancer early detection assay.
Esopredict, the firm's Barrett's esophagus risk stratification test, launched earlier this year and has been the main focus for the company's commercialization efforts. Barrett's esophagus is a precursor condition to esophageal cancer in which the tissue lining the esophagus changes and becomes more like the tissue that lines the intestines. According to Previse CEO Daniel Lunz, the test is intended to risk-stratify patients diagnosed with BE and receiving lifetime surveillance, predicting their risk of progressing to full-blown esophageal cancer.
Once that risk is known, clinicians can make decisions about whether to have patients undergo certain treatments — such as ablation — or continue monitoring them. The assay, originally developed at Johns Hopkins University, utilizes tissue biopsy samples and extracts and bisulfite-converted DNA while leveraging PCR to detect methylation in four target genes: P16, RUNX3, FBN1, and HPP1. Using a proprietary algorithm, the assay returns an Esoscore between zero and 10 indicating a patient's risk of progressing to esophageal cancer in the next five years.
Ten is the highest risk score, but the result is also sorted into one of four broader risk categories that clinicians may use to guide treatment decisions, Lunz said. Two of the categories are lower risk and two are higher risk. The low-risk category indicates that a clinician may consider extending surveillance intervals up to five years; the low-moderate risk group indicates that a clinician may consider extending surveillance up to three years; the high-moderate group may warrant more intensive surveillance; and the high-risk group indicates a clinician should consider endoscopic eradication therapy.
For patients with BE, a physician is "often faced with the challenge of, 'OK, when should I have this patient come back?'" Lunz said, adding the test could "reduce unnecessary procedures in those at lower risk."
The company's validation study is in review at a peer-reviewed journal, Lunz said. In an abstract presented last year at Digestive Disease Week outlining one of the test's validation studies, the test showed specificity of 90 percent, sensitivity of 31 percent, and negative predictive value at five years of nearly 99 percent.
In an abstract published in the American Journal of Gastroenterology last month, the test had a sensitivity of 100 percent and specificity of 67 percent in 41 patients with 105 profiled samples.
The commercialization of the test has been "progressing as we hoped," as the Johns Hopkins spinout has brought on additional sales personnel and added to its leadership team, according to Lunz. The company has also submitted an application for a PLA code to the US Centers for Medicare and Medicaid Services to receive official pricing and is awaiting the final price. While the test is not covered by any insurers, Lunz said the firm has been submitting claims for the test to both private and public payors for reimbursement and has been pleased with the response, although he did not comment on whether the company has received reimbursement.
The assay is currently offered as a laboratory-developed test, and Lunz declined to comment on its potential submission to the US Food and Drug Administration for approval as the company's regulatory strategy is still developing.
Last month, the firm received a $1.8 million grant from the National Institutes of Health to support additional clinical testing of Esopredict. The grant will be used for follow-on clinical validation studies and prospective clinical utility studies, all of which are ongoing and are "vital pieces in our commercialization strategy," particularly for achieving reimbursement, Lunz said.
A clinical utility study published in Medicine last year surveying 100 gastroenterologists found that 89 percent of respondents said the test would change their clinical practice in some manner and that the test's sensitivity and specificity would need to be 89 percent and 88 percent, respectively, to adopt the test into clinical practice.
Esopredict is not the only BE risk stratification test currently available, but other available tests use different technology or do not provide risk stratification results. Castle Biosciences' TissueCypher test uses spatial biology, artificial intelligence, and image-based analysis of biomarkers in tissue biopsies to determine a patient's risk of progressing to esophageal cancer within five years of endoscopy.
Meantime, Lucid Diagnostics offers its EsoGuard screening test that uses DNA bisulfite conversion, PCR amplification, and next-generation sequencing to determine the methylation status of 31 sites in the vimentin and cyclin A1 genes that indicate BE. The firm is also developing a test to risk-stratify patients that may develop esophageal cancer.
In addition to Esopredict, Previse is working on an early detection test for esophageal squamous cell carcinoma that will include a capsule device for less invasive sample collection. The test is a "more comprehensive solution to detect both major pre-malignancies and malignancies of the esophagus," Lunz said.
Completion of the test's development has been delayed partially due to the lagging effects of COVID-19 impacting prospective clinical studies, Lunz said, but validation studies for that test are "going full steam" ahead. In 2022, the company published a study in Gastroenterology on a gene panel for early detection of esophageal squamous cell carcinoma, and in 2019 published a study in Clinical Cancer Research validating biomarkers for the early detection of esophageal adenocarcinoma and precancerous Barrett's esophagus. Both studies are development studies for the firm's early cancer detection test, Lunz noted.
In the Gastroenterology study, the three-marker classification algorithm had an area under the receiver operating characteristic curve of 0.94, with specificity and sensitivity of 0.86 in its training set. In an independent test set, the algorithm successfully classified 90 percent of patients, with specificity of 0.87 and sensitivity of 0.92.
The company also has ongoing collaborations in the Netherlands, Uganda, and Tanzania and is working with Johns Hopkins, the University of California, San Francisco, and Allegheny Health Network on studies for the esophageal cancer test. It has also received grants from the NIH for the test's development.
Although Lunz declined to provide a timeline for when the esophageal cancer test will be on the market, he said that there will be "really interesting data" coming out for the test in 2024.