BOULDER, Colo.—This year’s IASLC Multidisciplinary Symposium in Thoracic Oncology hosted by the International Association for the Study of Lung Cancer featured a number of presenters, including Biodesix, which shared recent data regarding its VeriStrat test and its use in identifying patient subsets in lung cancer. The Symposium was held Sept. 22-24 in Chicago.
Biodesix’s presentation consisted of results of subset analyses of its TIGER-X and TIGER-2 clinical trials demonstrating that VeriStrat can stratify T790M-mutated patients with previously treated, advanced non-small cell lung cancer (NSCLC) who are more or less likely to experience longer progression-free survival (PFS) when treated with a third-generation EGFR-TKI therapy like erlotinib.
An individual’s EGFR mutation status is known to highlight NSCLC patients who see better outcomes when treated with EGFR-TKI therapy compared to standard platinum-doublet therapy in a front-line setting. There is, however, a subset of patients who will present with de-novo resistance, and acquired resistance is expected for all patients. In up to 60 percent of patients, the EGFR T790M mutation is the mechanism of resistance at progression.
The VeriStrat test is a predictive, prognostic blood-based proteomic test for patients with advanced NSCLC that determines disease aggressiveness by characterizing host response to the tumor. Patients are classified as either VeriStrat-Good (VS-G) or VeriStrat-Poor (VS-P), with results available within 72 hours, and Biodesix has previously shown that VeriStrat can predict survival outcomes for patients with advanced NSCLC who are treated with erlotinib.
Biodesix reported in a press release that its patients with VeriStrat test results had a median PFS of 127 days. PFS was analyzed for patients with ECOG status of 0 (63 patients; median 169 days) or 1 (169 patients; 125 days) and was found to have a hazard ratio of 0.85. Analyses compared VeriStrat test status Good and Poor for the entire T790M mutation positive patient pool for second-line patients alone and for third- and higher-line patients alone. For the entire cohort, the median PFS was 168 days for the VS-G patients vs. 91 days for VS-P patients, and for the second-line cohort, median PFS was 127 days for VS-G patients vs. 43.5 days for VS-P patients. For the third- and higher-lines cohort, median PFS was reported at 165 days for VS-G patients vs. 106 days for VS-P patients.
VeriStrat test status versus ECOG performance status was also analyzed. For ECOG status 1 patients, VeriStrat stratified patients by median PFS:153 days for VS-G patients vs. 102 days for VS-P patients.
The prognostic ability of this test was noted in a 2014 paper published in The Lancet Oncology titled “Predictive Value Of A Proteomic Signature In Patients With Non-Small-Cell Lung Cancer Treated With Second-Line Erlotinib Or Chemotherapy (PROSE): A Biomarker-Stratified, Randomised Phase 3 Trial.”
This work focused on patients with histologically or cytologically confirmed, second-line, stage IIIB or IV NSCLC who were enrolled in 14 centers in Italy. Patients were stratified to receive either erlotinib or chemotherapy, with a primary endpoint of overall survival (OS). All told, 142 patients were assigned to receive chemotherapy and 143 to receive erlotinib, with 129 (91 percent) and 134 (94 percent), respectively, included in the per-protocol analysis. As noted in the paper’s findings, “88 (68 percent) patients in the chemotherapy group and 96 (72 percent) in the erlotinib group had a proteomic test classification of good. Median overall survival was nine months in the chemotherapy group and 7.7 months in the erlotinib group. We noted a significant interaction between treatment and proteomic classification … Patients with a proteomic test classification of poor had worse survival on erlotinib than on chemotherapy. There was no significant difference in overall survival between treatments for patients with a proteomic test classification of good.”
VeriStrat is proving itself in other types of lung cancer as well. Biodesix announced on Oct. 5 that new clinical work shows that the test can identify patients with squamous cell carcinoma of the lung who are more likely to see longer PFS and OS with irreversible ErbB family blocker afatinib therapy over erlotinib.
“For patients with advanced squamous cell carcinoma of the lung who have ‘good’ status according to the VeriStrat test, EGFR-TKI therapy remains a relevant option, in addition to the recently approved checkpoint inhibitors for this patient population,” said Dr. Glenwood D. Goss, professor of medicine at the University of Ottawa. “The present data clearly show that EGFR-TKI therapy is useful for VeriStrat-Good patients and that afatinib confers significantly better survival than erlotinib, with median OS of 11.5 months versus 8.9 months. These survival data compare very favorably with other therapies that are currently available for the second-line treatment of patients with squamous cell carcinoma of the lung. While further validation studies are needed, the VeriStrat test has the potential to be clinically useful for guiding TKI therapy in squamous NSCLC.”
