NEW YORK (GenomeWeb) – Biodesix presented several studies on its Genestrat and VeriStrat lung cancer tests at the International Association for the Study of Lung Cancer's Multidisciplinary Symposium in Thoracic Oncology last week in Chicago.
The studies' data supported the utility of the two tests for detecting actionable mutations in lung cancer patients and guiding late stage therapy in those that have developed resistance to first line treatments.
Biodesix's Genestrat test is a droplet-based digital PCR test for identifying EGFR, EML4-ALK, KRAS, and BRAF mutations, while VeriStrat is a blood-based proteomic test for predicting response to therapy, and EGFR tyrosine kinase inhibitor therapy, in particular. The company offers the tests together as its Biodesix Lung Reflex product, in which patients are first tested for mutations using Genestrat and then patients without mutations are moved on to VeriStrat testing to determine who among them will likely respond well to EGFR inhibitor treatment.
One of the studies presented last week focused on the Lung Reflex test's turnaround time, which has proved a key advantage for the company, particularly in the community setting, Linda Traylor, Biodesix's senior director, scientific and medical affairs, told GenomeWeb.
Looking at 179 Lung Reflex tests performed across five different multidisciplinary thoracic oncology programs, the average time to results was 33 hours, compared to a median of 12 days for tissue-based testing.
"In multidisciplinary community settings we are seeing significant response to the [test's] turnaround time," Traylor said, noting that in such settings the test is being adopted as a tool for initial, rapid patient assessment.
Most commonly in this setting, she said, the Genestrat blood test is done during the initial biopsy. "If it is positive in blood then you have your answer," she said. "If it is negative, then I think there is a general consensus right now that they would reflex to tissue-based [mutation testing]."
Biodesix launched the Genestrat test last year as part of a larger move to expand beyond proteomics and into genomic testing. In addition to giving the company a foothold in genomics, the Genestrat test has also helped expand the market for Veristrat, Traylor said.
While Veristrat has been on the market since 2009, proteomic assays are less widespread in clinical practice than genomic tests, and Genestrat allows the company to introduce its offerings to doctors via a more broadly accepted form of molecular testing. In a January interview with GenomeWeb, Paul Beresford, the company's chief business officer, said that roughly 65 percent of Genestrat orders are accompanied by a Veristrat order, and that the company had seen an uptick in Veristrat sales since launching Genestrat.
"There is no question that Genestrat has played a significant role in driving awareness of the utility of Veristrat, Traylor said this week, adding that the percentage of Genestrat orders accompanied by a Veristrat order was now higher than the 65 percent Beresford cited/claimed earlier in the year.
One of the mutations detected by Genestrat is the EGFR T790M mutation, which is a marker of resistance to anti-EGFR drugs. Biodesix also presented at the IASLC meeting data showing the utility of Veristrat for predicting which patients with the EGFR T790M mutation would respond to third-generation EGFR inhibitors.
Around 60 percent of patients who develop resistance to first- and second-generation EGRF inhibitors have the T790M mutation, Traylor said. In the study, researchers used Veristrat to evaluate 230 patients with the mutation, finding that patients testing Veristrat-poor had progression free survival of 91 days compared to 168 days for those testing Veristrat-good when treated with a third-generation EGFR inhibitor.
The study, which Traylor said was the first to use Veristrat for stratifying patients with the T790M mutation, looked at cohorts from the TIGER-X and TIGER-2 clinical trials, which tested Clovis Oncology's EGFR inhibitor rociletinib in patients with EGFR T790M-mutated non–small cell lung cancer.
Traylor said that the TIGER trials failed to meet their primary endpoints, but that Biodesix had been able to identify a set of good responders using Veristrat. Clovis stopped developing rociletinib for EGFR T790M-mutated NSCLC this year.