1430P Excellent performance of a fast and fully-automated RNA based genefusion assay conducted on a large fusion positive non-small cell lung cancer cohort within a multicenter study

In patients with advanced non-small cell lung cancer (aNSCLC) timely therapeutic decision making is critical. In the past decade the treatment options for aNSCLC have expanded, along increased numbers of biomarkers that need to be tested, often on small and sparse material with multiple testing technologies. This may result in an undesired prolonged time to treatment and in the worst case even to non-feasible analysis. To elucidate the performance of the Idylla™ GeneFusion Assay, which simultaneously covers the biomarkers ALK, ROS1, RET and MET exon 14 skipping, a multicenter study was conducted in a routine clinical setting involving 12 clinical centers across Europe. A total of 326 archival aNSCLC formalin fixed paraffin embedded (FFPE) samples were included. The results of the Idylla™ GeneFusion Assay were compared with the biomarker status determined earlier with routine reference methods (including FISH, IHC, RT-PCR, and NGS). A total of 179 biomarker positive cases (85 ALK, 33 ROS1, 20 RET and 41 MET exon 14 skipping) were included, making this one of the largest fusion positive datasets tested. The Idylla™ detects ALK, ROS1 and RET fusions using both fusion specific and expression imbalance detection, allowing for the detection of less common fusions not covered by the fusion specific PCR’s. FFPE sample types used were 44% resected specimen, 46% tissue biopsies, 9% cytological specimen and 1% unknown. 67% of the centers used only 1 or 2 FFPE sections (5 or 10μm). The Idylla™ GeneFusion Assay demonstrated a low failure rate (0.9%). It showed also a high sensitivity/specificity, respectively for the following actionable biomarkers in NSCLC: 96.1%/99.6% for ALK, 96.5%/98.9% for ROS1, 100%/99.6% for RET and 92.5%/100% for MET exon 14 skipping. Since results are available within 3 hours, the Idylla™ GeneFusion Assay technology has emerged as a highly relevant time efficient upfront screening tool in FFPE samples. Moreover, detection of potentially novel fusions based on the principle of expression imbalance may be easily verified with either IHC, FISH or NGS without delaying the treatment initiation.