FIGURE 3.

FISH performed on ROS1+ NSCLC patient pleural fluid/ascites samples reveals MET gene amplification at progression on ROS1 TKI. A patient harboring a CD74‐ROS1 fusion attempted a series of ROS1 TKIs due to unmanageable side effects. From both the CUTO38 cell line (derived April 2018 following progression on crizotinib) and a sample obtained during repotrectinib treatments (January 2020), MET FISH revealed a MET/CEP7 ratio of 1.1 or 0.9, respectively. When the patient returned to clinic in May 2020 with recurrence, a sample collected from ascites fluid and subjected to FISH revealed a MET/CEP7 ratio of 2.5. All images were taken at 100x magnification