Introduction: Crizotinib is an oral multitargeted tyrosine kinase inhibitor (TKI) with activity against lung cancers driven by ALK-rearrangements, ROS1-rearrangements and MET-amplification. Comprehensive genomic profiling (CGP) based on clinical next generation sequencing (NGS) can detect crizotinib-sensitive genomic changes. We describe use of CGP to identify tumors responsive to crizotinib.
Methods: Retrospective review of representative lung adenocarcinomas treated with crizotinib and assayed with a clinical NGS assay.
Results: We report 3 cases of lung adenocarcinoma; one each identified to harbor an ALK-rearrangement (EML4-ALK), ROS1-rearrangement (SDC4-ROS1) and MET-amplification by genomic profiling. Notably, the MET-amplification was only detected by CGP as subsequent FISH testing did not show amplification. CGP also revealed other common genomic changes (somatic mutations [TP53 in 2 cases], deletions [CDKN2A in 1 case], amplifications [MCL1 in 1 case] and variants of unknown significance) in these cases. All patients received crizotinib 250 mg twice daily and achieved radiographic tumor reduction for months. The case harboring MET amplification of 10 copies achieved partial response and is one of the first MET-amplified lung cancer responsive to crizotinib in which the sole detection method was CGP.
Conclusions: CGP holds the promise of detecting predictive genomic alterations (somatic mutations, copy number changes and rearrangements) that may underlie tumor dependency in an oncogene and govern response to clinically-available TKIs for lung adenocarcinomas.
Keywords: Anaplastic lymphoma kinase; C-ros oncogene 1; Hepatocyte growth factor receptor; Mutation; Next-generation sequencing.