Exosome liquid biopsies of NSCLC patients for longitudinal monitoring of ALK fusions and resistance mutations.

e24090Background: Molecular profiling of mutations in NSCLC patients is of increasing relevance for direction of targeted therapy. Assessing such biomarkers directly from plasma overcomes hurdles associated with biopsies, including significant risk and difficulties to monitor molecular changes longitudinally. Here we applied molecular testing for detection of EML4-ALK fusions and ALK resistance mutations in exosomal nucleic acids from plasma of lung cancer patients. In a prospective cohort of ALK-positive patients the longitudinal monitoring of response to treatment by liquid biopsies in correlation to routine diagnostics was investigated. Methods: In an accredited laboratory the ExoDx Lung(ALK) test was used for variant-specific detection of EML4-ALK from exosomal RNA of patient plasma using a validated qPCR panel. In parallel, ALK resistance mutations were analyzed on exosomal RNA as well as cfDNA using our ExoLution Plus platform that simultaneously isolated exosomal RNA and cfDNA. 11 ALK exon23-based ...