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Cleveland Diagnostics Aims to Drive IsoPSA Test Into New Prostate Cancer Indications, Markets


NEW YORK – Backed by a recently closed $75 million funding round, Cleveland Diagnostics is looking to drive further uptake of its IsoPSA prostate cancer test and move into new areas including additional cancer indications and neurodegenerative disease.

The company is also pursuing US Food and Drug Administration clearance for its test, which CEO Arnon Chait said will provide it with a competitive advantage in the increasingly crowded prostate cancer testing space.

The IsoPSA test is based on Cleveland Diagnostics' Solvent Interaction Analysis (SIA) technology, which uses two-phase aqueous solutions to separate patient samples in ways that are diagnostically useful.

Essentially, samples are added to two-phase solutions containing various molecules like polymers and salts. Different proteins and protein forms within the sample will then move to one of the two phases based on their interactions with the salts and polymers in the solution. By testing different combinations of molecules, the company develops two-phase solutions that separate patient proteins in a way that allows for disease detection, the idea being that under the right conditions, a cancer-related protein isoform will move to the opposite phase from healthy protein isoforms, and that disease can be diagnosed by analyzing the amount of proteins in each phase.

The IsoPSA test separates cancer-linked isoforms of the protein prostate-specific antigen (PSA) from PSA isoforms not linked to cancer. The total amount of protein in each phase is then measured via ELISA, and the ratio of the total protein in the two phases is used as a score of prostate cancer risk.

According to the company, the advantage of this approach is that it allows the test to take into account the full complement of PSA isoforms as opposed to the handful of markers measured in more targeted tests.

Cleveland Diagnostics currently offers IsoPSA as a laboratory-developed test available throughout the US excluding New York. Chait said the company has performed the test on tens of thousands of patients to date, with clinicians using it primarily to assess the likelihood that an individual with an elevated PSA score has high-grade prostate cancer. In 2022, the test was added to the National Comprehensive Cancer Network (NCCN) Guidelines for Prostate Cancer Early Detection as an option for assessing a patient's risk of high-grade disease.

Chait said Cleveland Diagnostics is also working to build evidence for several other use cases, for instance, regular monitoring of patients with low-grade prostate cancer who have opted for active surveillance rather than surgery. Last year researchers from the Cleveland Clinic, which owns an equity stake in the firm, presented data at the 2023 ASCO Genitourinary Cancers Symposium looking at 811 surveilled prostate cancer patients and showing that after 18 months of follow-up, 1.1 percent of patients with normal baseline IsoPSA scores developed clinically significant disease compared to 28.5 percent of patients with high baseline IsoPSA scores.

The company is also exploring what its test can add to imaging approaches like MRI that have become more commonly used in diagnosing prostate cancer. Last year, a team including researchers from the Cleveland Clinic published a study in Urology indicating that a low IsoPSA score could provide added confidence that patients with negative or equivocal MRIs could safely forego biopsy.

To date, Cleveland Diagnostics has primarily targeted urologists with the test, but Chait said that it hopes through its 2023 deal with Quest Diagnostics to make inroads into the primary care market.

"They have thousands of phlebotomy access points and many salespeople who actually speak to the PCP community," Chait said.

In late 2017, Cleveland Diagnostics entered into an agreement with Genomic Health, giving that company (which was acquired by Exact Sciences in 2019) exclusive global rights to commercialize the IsoPSA test. Genomic Health ended the deal the following year, however, in what then-Chief Operating Officer Fred Pla said was a business decision based on an internal review process.

Chait said that shortly after the deal was signed both parties realized that Genomic Health's relative lack of experience in both protein-based assays and the FDA regulatory process made the two companies a poor match.

Regarding an FDA submission, Chait declined to give a timeline for when the company might see a decision on IsoPSA, but he called its efforts "quite advanced." Cleveland Diagnostics received FDA breakthrough device designation for the test in 2019.

Chait said that securing FDA approval will be key to driving uptake of the test and to competing with the multiple other PSA reflex tests on the market. Noting that he considered ExosomeDx's ExoDx Prostate Test, Opko Health's 4Kscore, and MDxHealth's Select MDx tests as the main competition for IsoPSA, he said he did not expect these tests to compete primarily on performance but would be distinguished by their ability to move into other indications within prostate cancer and their benefit to urologists both from an ease-of-use and business perspective.

Regarding the latter point, Chait said he believes that IsoPSA's simplicity and low testing costs will enjoy an advantage, provided it receives FDA clearance and can be sold as distributed kits as opposed to LDTs.

Urology practices with their own immunoanalyzers will be able to purchase the test as kits, run it locally, and bill insurers themselves, Chait said, noting that the test's low cost of goods means both the doctors and Cleveland Diagnostics will be able to enjoy high margins from these sales. The IsoPSA test received national coverage from the Centers for Medicare and Medicaid Services starting Jan. 1 at a price of $760. Chait said the test currently runs on Roche analyzers but that the company plans in the near future to expand to analyzers from other firms.

Chait said Cleveland Diagnostics is also working to apply its SIA technology to develop reflex tests for breast and lung cancer, two other cancers where clinicians are often faced with decisions about whether or not to biopsy based on an initial finding. He said the technology could also be a good fit for neurodegenerative diseases where it might prove effective at identifying the protein conformational changes characteristic of conditions like Alzheimer's and Parkison's.