Prospective Efficacy of Osimertinib in Circulating Tumour DNA (ctDNA) T790M-Mutant NSCLC Patients [P2.13-24]

BACKGROUND : Liquid biopsy circulating tumor DNA (ctDNA) analysis in advanced EGFR-mutant NSCLC patients is an approved tool for molecular profiling and disease surveillance when tissue is not available. Long-term efficacy of osimertinib in patients with the T790M resistance mutation positive detected only by ctDNA (without tissue information) has not been fully validated. [...

The amount of activating EGFR mutations in circulating cell-free DNA is a marker to monitor osimertinib response

BACKGROUND: Circulating cell-free DNA (cfDNA) may help understand the molecular response to pharmacologic treatment and provide information on dynamics of clonal heterogeneity. Therefore, this study evaluated the correlation between treatment outcome and activating EGFR mutations (act-EGFR) and T790M in cfDNA in patients with advanced NSCLC given osimertinib. METHODS: Thirty-four NSCLC patients resistant to first/second-generation EGFR-TKIs, positive for both act-EGFR and T790M in cfDNA at the time of progression were enrolled in this study. Plasma samples were obtained at osimertinib baseline and after 3 months of therapy; cfDNA was analyzed by droplet digital PCR and results were expressed as mutant allele frequency (MAF). RESULTS: At baseline, act-EGFR MAF was significantly higher than T790M (p  2.6% and  0.22 (6 months vs. not reached, respectively, p = 0.01). CONCLUSION: act-EGFR MAF and T790M/act-EGFR MAF ratio are potential markers of outcome in patients treated with osimertinib

Mobile Genome Express (MGE): A comprehensive automatic genetic analyses pipeline with a mobile device

The development of next-generation sequencing (NGS) technology allows to sequence whole exomes or genome. However, data analysis is still the biggest bottleneck for its wide implementation. Most laboratories still depend on manual procedures for data handling and analyses, which translates into a delay and decreased efficiency in the delivery of NGS results to doctors and patients. Thus, there is high demand for developing an automatic and an easy-to-use NGS data analyses system. We developed comprehensive, automatic genetic analyses controller named Mobile Genome Express (MGE) that works in smartphones or other mobile devices. MGE can handle all the steps for genetic analyses, such as: sample information submission, sequencing run quality check from the sequencer, secured data transfer and results review. We sequenced an Actrometrix control DNA containing multiple proven human mutations using a targeted sequencing panel, and the whole analysis was managed by MGE, and its data reviewing program called ELECTRO. All steps were processed automatically except for the final sequencing review procedure with ELECTRO to confirm mutations. The data analysis process was completed within several hours. We confirmed the mutations that we have identified were consistent with our previous results obtained by using multi-step, manual pipelines