NEW YORK (GenomeWeb) – Recent publications and company comments suggest diagnostics firm Biodesix is shifting its strategy around its Veristrat lung cancer test.
The firm has historically marketed the test with a focus on its predictive capabilities, particularly around patient response to tyrosine kinase inhibitors (TKIs) targeting EGFR.
Over the last year or so, though, it has begun more strongly emphasizing Veristrat's prognostic power, a move that some observers and users of the test suggest stems from skepticism among clinicians of its predictive utility as well as from a 2016 study indicating a potential place for the test as a prognostic assay.
Veristrat uses MALDI mass spectrometry to measure serum protein signatures in lung cancer patients with the aim of assessing the aggressiveness of their disease and predicting the effectiveness of particular therapies. Based on their test results, patients are determined to be either a Veristrat "good" or "poor," with good typically indicating a better prognosis and higher likelihood of response to treatment, though the company and its collaborators are still exploring the various clinical implications of the two categories.
Biodesix launched the test in 2009 and hit what one doctor, Howard West, medical director of the thoracic oncology and genitourinary oncology programs at Seattle's Swedish Cancer Institute, called a "high-water mark" of clinician interest following the presentation at the 2013 American Society of Clinical Oncology annual meeting of data from its PROSE trial, in which researchers determined that Veristrat "poor" patients with either wild-type EGFR status or unknown EGFR mutation status were likely to fare poorly on the EGFR inhibitor erlotinib and should be given chemotherapy instead. Meanwhile, Veristrat "good" patients were equally likely to respond to either therapy, allowing that subset of patients to avoid chemotherapy and its side-effects.
"The PROSE study was the point where we said, 'OK, well, maybe,'" West said. But, he added, that data ultimately wasn't enough for the test to gain significant traction, particular given that erlotinib is no longer indicated for wildtype EGFR patients.
"The most it could possibly ask is, 'Is it even worth trying erlotinib," West said. "But that question has largely gone away with the removal [in 2016] of the indication for erlotinib in wildtype patients. So, it answers no questions that we actually would choose to ask in clinic."
Following the presentation of the PROSE data in 2013, Nathan Pennell, director of the Lung Cancer Medical Oncology Program at the Cleveland Clinic Taussig Cancer Center, told GenomeWeb that the prospective data generated in the trial would make him consider ordering the test to guide second-line therapy. However, contacted via email several months ago to discuss Veristrat, Pennell said that he didn't use the test.
"I give [Biodesix] credit for doing research and actually testing prospectively," West said. "But it has not been enough to change practice."
Nonetheless, Wendy Blosser, Biodesix's chief commercial officer, said sales volume of the test is currently the highest it has been since its launch and has been growing quarter-over-quarter since she came to the company in 2015. The privately held company, however, declined to provide sales figures for the test.
She noted that while the company has in the past put significant emphasis on the test's potential role in guiding TKI therapy, a number of trials have also demonstrated that "Veristrat poor patients are identified with an aggressive disease state that is associated with poor prognosis," and that the company sees "utility in the test for planning, monitoring, as well as for patient counseling."
In September, the company sponsored a literature review published in Managed Care making the case for Veristat as a prognostic tool and looking specifically at how it might fit into the Centers for Medicare and Medicaid Services' Oncology Care Model payment frameworkl.
West suggested, though, that a prognostic test doesn't really address clinicians' needs in lung cancer.
"You are measuring that this is an aggressive or indolent cancer or that this person is sickly versus this person is robust," he said. "Either way, we gauge this all the time. We use 10 other cues when we are assessing a patient and their cancer to get a sense of their fitness and the relative aggressiveness of the cancer. I just don't feel there is the pain in the market for this."
Paul Walker, a thoracic oncologist and associate professor at East Carolina University's Brody School of Medicine, said, however, that a 2016 study led by Biodesix scientists and published in the British Journal of Cancer provides what he feels is compelling evidence for Veristrat's utility as a prognostic test, at least in patients with stage IV disease. Walker is not a Biodesix employee but has participated in studies of the test and received fees for attending meetings of the company's advisory board.
Looking at 83 patients with non-squamous non-small cell lung cancer, 43 of whom were treated with carboplatin and pemetrexed and 40 of whom were treated with cisplatin and pemetrexed, the researchers found that Veristrat good patients had median progression-free survival of 6.5 months versus 1.6 months for Veristrat poor patients and that median overall survival for good patients was 10.8 months compared to 3.4 months for poor patients.
Looking at the different treatment groups, for the carbo-pem patients, median PFS was 3.8 months and 1.6 months in the good and poor groups, respectively, and median OS was 9.4 months and 3.4 months, respectively. For the cis-pem group, the median PFS was 7.9 months in the good group and 1.7 months in the poor group, and the median OS was 17.7 in the good group and 4.2 months in the poor.
These findings, "completely changed my view of the utility of Veristrat," Walker said, noting that he had not been impressed by previous studies by Biodesix and its collaborators around the test's role for guiding TKI therapy.
"That whole initial focus around differentiating between chemotherapy and a TKI in non-EGFR-mutated lung cancer was sort of a non-decision," he said. "I think there was hope it was going to be the great decider [for TKI therapy] based on the PROSE study, but [clinicians] didn't really need a test to do that."
The BJC study, on the other hand, indicates prognostic utility that could improve upon existing measures, Walker said. "It trumps performance status. It trumps some other of what we felt were reliable prognostic indicators."
"It certainly does seem to reflect the host response to the tumor, the tumor activity, and it clearly seems to be a prognostic test in that if you are Veristrat poor you are going to do much more poorly than if you are Veristrat good," he said. Poor patients "are not going to have any benefit from just standard, standalone cytotoxic chemotherapy in the non-squamous setting."
What therapy, if any, is optimal for these patients is yet to be determined, "but it is clear that you have to do something different," Walker said, noting that immunotherapies singly or in combination with each other or with chemotherapies offer potential treatments.
Walker said that he didn't believe Biodesix or other supporters of Veristrat within the lung cancer community had necessarily done an effective job yet articulating the prognostic case for the test and acknowledged that, as West suggested, it is not widely used at present. He added that the failure of the company's earlier focus on guiding TKI therapy to take off had likely contributed to current skepticism around the test.
"I'm hanging a lot on the BJC study," he said. "It's a sort of proof-of-principle that there may be a utility to something that was perhaps just used the wrong way before. To me it opens up potentially significant advances."