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Guardant Health, MD Anderson Look to Establish Liquid Biopsy as Standard-of-Care Practice


NEW YORK (GenomeWeb) – Guardant Health announced last week that it is entering a new partnership with MD Anderson Cancer Center that it believes will help push its technology for blood-based cancer biomarker testing into the standard of care.

Although liquid biopsy tests like Guardant's have had an extremely rapid rise, their use is still fairly limited, and the field continues to express caution around the question of whether blood-based cancer genomics could be used more widely for all patients, or should be limited to only those for whom tissue-based analysis is impossible or especially onerous.

In an interview last week, Guardant CEO Helmy Eltoukhy and MD Anderson's head of pathology and laboratory medicine Stanley Hamilton fleshed out some details about how the collaboration will affect the use of Guardant's test at MD Anderson right now and in the future, and the steps they are taking on the research side to achieve their stated goal.

The partnership between Guardant and MD Anderson has two intertwining aspects. The first speaks to current clinical practice, in that the institution has pledged to name Guardant's clinical test, Guardant360, as the "test of choice" for its physicians.

Hamilton said that MD Anderson clinicians have been using liquid biopsy tests from a number of different companies, making their choices largely on whether they need a more comprehensive test like Guardant's or a more focused panel with fewer genes or even a single target.

Now, in partnership with Guardant, the center hopes to move as rapidly as possible toward establishing when and how Guardant360 is the most clinically useful, making the assay available for doctors to order through the institution's electronic medical record system, informing payors that the test is part of MD Anderson's standard of care, and persuading them to pay for it.

At MD Anderson, this process is led by a group called the Molecular Testing Evaluation Committee, Hamilton said.

"One of the real issues with any of these molecular tests unfortunately is reimbursement. These things have to be paid for, because they are relatively expensive as far as lab tests go," he said.

Hamilton said MTEC involves participation from a variety of groups including physicians and other care providers, billing compliance staff, and patient advocates.

The committee looks at available evidence, either in the published medical literature, or from MD Anderson's own published or unpublished research, and members vote on whether or not a particular molecular test is ready to move into the standard of care.

"Once that is done we create a document around those decisions, and the reasoning behind them, and that can be used with the medical officers of third party payor to provide evidence that these tests should be reimbursed," Hamilton said.

"It's worked very well for us in [tissue testing] in solid tumors and in liquid tumors, and now we want to take the same approach in liquid biopsy," he added.

Simultaneously, MD Anderson is also embarking on a variety of research studies with Guardant to both support MTEC's efforts and potentially answer other open questions about how best to use liquid biopsy tests like Guardant's.

Most basically, Hamilton said, MD Anderson still believes more data needs to be collected on how well liquid biopsy compares to tumor tissue test results, to make sure that when blood-based test results are acted upon, clinicians (and payors) can expect the same results in terms of improved outcomes for their patients.

Beyond that, the field also has to establish how circulating DNA changes over time and in response to treatment and, and whether testing patients after surgery or other treatments can help guide the use of adjuvant therapies.

More importantly for potential standard-of-care usage, data is required showing that these extended applications like monitoring circulating DNA to guide adjuvant treatment or otherwise inform care actually improve patients' health.

"There is a great amount of detail and granularity in how these tests perform that we don't understand," he said. "One reason why we are doing this with Guardant is that they made it clear that they are willing to work on the assay itself and the performance of it, and in particular to look at performance characteristics in various scenarios."

Hamilton did not provide a timeline for the process of decision-making by MD Anderson's MTEC.

"Because our center is relatively large, we should be able to accumulate data quickly on how this performs in the general practice of oncology … [and] once the committee has made this decision, discussion is typically open with the [companies] we know are the major payors for patients that come to us," he said.

"We try to, prospectively if we can, let them know this new test is coming onto our roster and provide the evidence from the literature and our own experience that it should be paid for," he added. "Once that is set up, our clinical effectiveness committee sets up an electronic order set in the EHR and at that point it can be ordered like any other test," he explained.

Since it launched Guardant360, Guardant has highlighted the breadth of its sequencing panel as a strength and a distinguisher from some other liquid biopsy approaches on the market.

But as the MD Anderson research work goes forward, Hamilton and Eltoukhy said that the data may indicate that certain clinical settings require different versions or subdivisions of the company's comprehensive targeted sequencing panel as it stands.

How that might play out is yet to be seen, Hamilton said. According to Eltoukhy, Guardant is prepared for the potential development  of completely new tests as part of the partnership, possibly looking at things like body fluids other than blood, for example.

Overall, though, he said the research will be focused on the most pressing clinical unmet needs as determined by MD Anderson.

Guardant is also hoping that other partner institutions will mimic MD Anderson's efforts to move liquid biopsy into the standard of care.

The company previously announced that Northwestern University had agreed to name its test as the preferred liquid biopsy option for patients at its Robert H. Lurie Comprehensive Cancer Center, and Eltoukhy said that the firm also expects to make other similar announcements soon.