In an ongoing phase I trial, the ALK tyrosine kinase inhibitor (TKI) crizotinib shows remarkable initial responses in patients with non-small cell lung cancer (NSCLC) harboring ROS1 fusions; however, cancers eventually develop crizotinib resistance due to acquired mutations such as G2032R in ROS1.
Non-small-cell lung cancer (NSCLC) patients harboring ALK or ROS1 rearrangements invariably acquire resistance to the first- and second-generation tyrosine kinase inhibitors (TKIs), most notably ALK G1202R and ROS1 G2032R.
Development of the acquired ROS1 G2032R mutation has been reported as a resistant mechanism to ROS1 inhibitors in ROS1-rearranged (ROS1<sup>+</sup>) NSCLC patients.
We performed a biopsy of a resistant tumor and identified an acquired mutation leading to a glycine-to-arginine substitution at codon 2032 in the ROS1 kinase domain.
The effect of the identified drug was assessed in the CD74-ROS1-mutant Ba/F3 cells and crizotinib-resistant patient-derived cancer cells (MGH047) harboring G2032R-mutated CD74-ROS1.
Here we report that DS-6051b is effective in treating ROS1- or NTRK-rearranged cancer in preclinical models, including crizotinib-resistant ROS1 positive cancer with secondary kinase domain mutations especially G2032R mutation which is highly resistant to crizotinib as well as lorlatinib and entrectinib, next generation ROS1 inhibitors.
Here we report that DS-6051b is effective in treating ROS1- or NTRK-rearranged cancer in preclinical models, including crizotinib-resistant ROS1 positive cancer with secondary kinase domain mutations especially G2032R mutation which is highly resistant to crizotinib as well as lorlatinib and entrectinib, next generation ROS1 inhibitors.
The effect of the identified drug was assessed in the CD74-ROS1-mutant Ba/F3 cells and crizotinib-resistant patient-derived cancer cells (MGH047) harboring G2032R-mutated CD74-ROS1.
Combination of Twist1 siRNA and crizotinib significantly reduced cell vitality, inhibited cell invasion and migration, and promoted apoptosis in A549-CD74-ROS1 G2032R mutation cells.
Non-small-cell lung cancer (NSCLC) patients harboring ALK or ROS1 rearrangements invariably acquire resistance to the first- and second-generation tyrosine kinase inhibitors (TKIs), most notably ALK G1202R and ROS1 G2032R.
These results demonstrated how the mutated residues tune the crizotinib response and may assist kinase inhibitor development especially for ALK G1202R, analogous to the ROS1 G2302R and MET G1163R mutations that are also resistant to crizotinib treatment in NSCLC.
We report the discovery of a novel, solvent-front ROS1(D2033N) mutation in a patient with CD74-ROS1-rearranged lung adenocarcinoma and acquired resistance to crizotinib.