Initial validation of a highly sensitive RT-qPCR assay for detecting all fusions and wild-type upregulation of ALK.

e21070 Background: Anaplastic lymphoma kinase (ALK) fusions cause a variety of malignancies (e.g. NSCLC and NHL). Patients with ALK fusion-driven cancers treated with the ALK inhibitor crizotinib, currently in clinical trials, have had marked antitumor responses. There are 15+ ALK fusions reported in NSCLC and other cancers, and testing by fluorescence in situ hybridization (FISH) has shown ALK gene amplification in cancers as well. The clinical significance of amplification is currently undetermined. We report results from a novel RT-qPCR assay (Insight ALK Screen) that is unbiased toward fusion partners and also detects wild-type upregulation. Results were compared to FISH and immunohistochemistry (IHC) to assess the accuracy of the qPCR assay and to correlate mRNA expression with gene amplification. Methods: Twenty-three NSCLC FFPE specimens were blinded and analyzed by the qPCR assay. ALK mutation status was independently determined by FISH and IHC. FISH studies used the ALK break-apart probes (Abbott...