ROS1 and central nervous system neoplasm: Entrectinib was tested in the phase I and phase II STARTRK trials and showed promising results in pediatric and adult CNS tumors harboring NTRK fusions with an ORR of 50% (12, 86), and is being further evaluated in a phase 2 trial of children less than 3 years old with CNS tumors harboring NTRK or ROS1 fusion (34).