The plasma test VeriStrat can predict response but not survival benefit from erlotinib in patients with advanced non-small cell lung cancer (NSCLC).

VeriStrat is a commercially available serum-based or plasma-based test that uses matrix-assisted laser desorption ionization mass spectrometry methods to classify the prognosis of patients as Good or Poor. This study used plasma samples from 441 of the patients with advanced NSCLC who were enrolled in a phase III clinical trial of erlotinib versus placebo.

Testing by VeriStrat was successful in 98.9% of the samples (n=436). Among the 61% of patients whose prognosis was classified as Good, the median survival was 10.5 months on erlotinib versus 6.6 months on placebo. For the patients whose prognosis was classified as Poor, the median survival was 4 months on erlotinib versus 3.1 months on placebo.

This research confirmed that VeriStrat was predictive for response. When the research team examined if VeriStrat was predictive for a differential survival benefit versus placebo, they found it was not; both the Good and Poor patient cohorts derived a similar relative benefit from erlotinib. Among patients who did not receive erlotinib, VeriStrat was prognostic for both progression-free survival and overall survival.

For patients who did receive erlotinib, VeriStrat was able to predict response, but not progression-free survival or overall survival. The study stated that VeriStrat is “prognostic biomarker in previously treated patients with advanced NSCLC. Further studies are required to define the clinical utility of VeriStrat and other blood-based biomarkers in defining the appropriate patient population for therapy with erlotinib and other EGFR-based therapies.”

This research was published in the Journal of Thoracic Oncology (2012;7[11]:1653-1660).