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Theralink Using Phosphoproteomics to Guide Treatment in Late-Stage Breast Cancer


NEW YORK – Cancer diagnostics firm Theralink Technologies is working to commercialize a phosphoproteomics-based assay for guiding treatment in late-stage breast cancer.

Based on technology launched more than a decade ago by George Mason University spinout Theranostics Health, the test measures the activation levels of cancer-linked protein signaling pathways to identify classes of drugs to which patients are likely to respond.

Denver-based Theralink launched the current version of the assay in January 2021 and has since run the test in more than 100 patients as it aims to build a body of evidence demonstrating its clinical utility. The company is also working on a pan-cancer assay that it plans to offer to guide therapy across a variety of cancers.

The test uses the reverse-phase protein array (RPPA) technology developed by GMU researchers Emanuel Petricoin and Lance Liotta, both cofounders of Theralink's predecessor, Theranostics Health and, chairs, respectively, of Theralink's scientific and medical advisory boards. RPPA uses cell lysates spotted in array formats that can then be probed with antibodies to multiple proteins of interest.

Protein phosphorylation is essential to cell signaling and regulation. Over the last two decades, kinase inhibitors that target aberrant protein phosphorylation have emerged as a major area of drug development in cancer and other diseases. The Theralink test measures protein expression and phosphorylation across 32 analytes.

Researchers like Oregon Health & Science University's Gordon Mills and GMU's Petricoin and Liotta have made extensive use of antibody-based approaches to measure protein phosphorylation in tumor samples and, in some cases, helping to guide treatment.

The National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium has also made extensive use of phosphoproteomic analyses with, for instance, CPTAC researchers using proteogenomics and phosphoproteomics to investigate mechanisms of drug resistance and identify potential drug targets in triple-negative breast cancer.

Meanwhile, UK-based proteomics startup Kinomica is using phosphoproteomics to help guide therapy in acute myeloid leukemia patients, and Branford, Connecticut-based single-cell omics firm IsoPlexis offers a research assay that measures 15 phosphoproteins and proteins involved in tumor signaling.

Theranostics Health launched in 2006 and released its first commercial test in 2013 — an RPPA-based assay that measured protein expression and phosphorylation across 14 analytes. Called the TheraLink HER Family Assay, the test was intended as a supplement to conventional HER2 testing for guiding therapy in breast cancer patients, particularly in metastatic cases.

Among the rationales for the test was the finding by researchers including Petricoin that certain patients who were HER2-negative based on conventional immunohistochemistry and fluorescence in situ hybridization testing showed phosphorylated HER2 and activation of HER2 signaling pathways, indicating that they might be candidates for anti-HER2 therapies.

Yet, despite the centrality of phosphorylation to cancer signaling and phosphoproteomics' potential as a tool for developing and guiding cancer therapies, Theralink has, across its many incarnations, struggled to drive clinical uptake of its tests. After operating as an independent business for almost a decade, Theranostics Health was acquired by Avant Diagnostics in 2016. In 2020, Avant was acquired by OncBioMune Pharmaceuticals, a biopharma firm that was publicly traded on the OTC Markets. Following the acquisition, OncBioMune's activities were discontinued and the company's name was changed to Theralink Technologies, which now trades on the OTC Markets under the symbol "THER."

Matthew Schwartz, a radiation oncologist with Comprehensive Cancer Centers of Nevada, said that he hadn't been aware of Theralink or its test until hearing about it from a colleague. He said that his first inclination was to assume that it probably wasn't useful, but after looking into it and discussing it with other clinicians, he decided to give it a try.

He said that thus far he has been using it on late-stage patients who run through the standard of care.

"They have already been heavily pre-treated, they have already had NGS testing, they have had liquid biopsies, and we don't know what to do," he said. "And so, I figure we have nothing to lose by trying a new test. It gives really interesting results. My experience with it as a clinician has been very positive, so far."

Schwartz said that in his experience, the Theralink assay frequently provides an actionable result, which he noted contrasts with genetic testing to identify actionable mutations.

"When [genetic testing] works, it can be like a miracle, but it doesn't work very often," he said. "With breast cancer, we will see something we can actually do something with like, 5, 10 percent of the time, and then of that, the treatment you give actually works like half the time. And for those patients it can be like a miracle. They can go from being on hospice to going back to work and having years of good, quality life."

"Theralink is super interesting to me because it almost always gives me something that you can potentially do something with," Schwartz said. "Now, whether or not you can get the drug, whether it is FDA approved, is a different story. But for almost every single patient I have ordered the test on, it has given me an activated protein pathway, a scientific rationale for why you should choose this treatment or that treatment."

Under a 2020 agreement, Theralink has partnered with McLean, Virginia-based precision oncology firm Perthera, which was also cofounded by Petricoin, to provide virtual tumor board services helping doctors interpret the data provided by the Theralink test and other assays. Schwartz said this feature was particularly useful for clinicians working in the community setting who may not be able to convene tumor boards as is commonly done in academic hospitals.

Theralink has been collecting data on the test's actionability from Schwartz and other ordering clinicians. This month the company said that in a cohort of 118 patients with advanced breast cancer, the test provided information that was "actionable for patient treatment selection" 90 percent of the time.

Schwartz said that the fact that major studies like the I-SPY2 breast cancer trial had used RPPA and identified potential markers of drug response via the technology was legitimizing, but added that Theralink would need more prospective data to drive uptake of its tests.

"If you're looking at a biomarker and deciding, OK, I want to give this treatment or that treatment, I think prospective data is the key that kind of proves it," he said, noting that this would be particularly necessary for the company to move the test to earlier points in the treatment process.

"Right now, I'm using it for patients … that don't really have a lot of good treatment options, where we don't know what to do," he said. "But in order for it to be more mainstream, to be used earlier in care, you're going to need to see more data."

Kris Weinberg, Theralink's director of oncology, commercial markets, said the company is currently sponsoring an observational study "to establish the clinical utility" of the test in order to build support for the test with payors. He said Theralink launched the study last year in collaboration with Perthera and expects it will have accrued enough patients by the end of the year to submit the study for peer-review publication. He said the company aims to enroll around 300 individuals.

Theralink announced this week that it is collaborating with Sioux Falls, South Dakota-based Avera Health, a healthcare system operating 300 locations across five states in the Upper Midwest, to incorporate its RPPA data into molecular profiles of cancer patients being treated within the Avera system. Mick Ruxin, Theralink's president and CEO, said he expects Theralink will run its test on thousands of patients through the collaboration.

The company will also use retrospective case analyses and population-based data provided by Avera to help validate assays for additional cancer types.

Ruxin said Theralink has not to date charged patients for its assays. He said the company has submitted information to the appropriate Medicare Administrative Contractors to establish a reimbursement rate for the test and that it will begin submitting test claims to Medicare and private insurers once it has received a rate. He added that the company plans to price the test at $3,500, though it does not intend to charge patients out of pocket initially.

In addition to its testing business, Theralink also has a pharma services business from which it currently derives the bulk of its revenues. According to the company's most recent Form 10-K, it had $505,604 in revenues for the fiscal year 2021 ended Sept. 30, up from $181,229 in 2020. Its net loss for fiscal year 2021 was $6.6 million, up from $5.2 million in 2020.

At the end of 2021, Theralink had $414,982 in cash. Ruxin said the company plans to raise additional funds before the end of the year.