Crizotinib in ROS1 Rearranged NSCLC

D. Ross Camidge, MD, PhD, Director, Thoracic Oncology Clinical Program, University of Colorado Cancer Center, discusses the potential to utilize crizotinib as a treatment for patients with advanced non-small cell lung cancer (NSCLC) who harbor a ROS1 gene rearrangement.

The ROS1 gene rearrangement is very similar to the ALK fusion and, as a result, it can be targeted by treatment with crizotinib, Camidge states. This alteration occurs in approximately 1% of patients with NSCLC and has been implicated in other types cancer, including colorectal.

Clinical Pearls

Evidence presented at the 2013 ASCO Annual Meeting suggests that crizotinib elicits a response rate of 50% to 60% in patients with ROS1 rearrangements. However, as a very rare subtype of NSCLC, expanding the approval of crizotinib to include patients with ROS1 will require ongoing conversations with the FDA, since the patient population is too small for a large phase III trial. Hopefully, Camidge notes, the approval can be granted based on small trials, since ROS1 is so similar to ALK.

• The ROS1 gene rearrangement is very similar to the ALK fusion
• In NSCLC patients with ROS1 rearrangements, crizotinib elicited a response rate of 50% to 60%
• There are too few patients with ROS1 alterations to conduct a phase III trial
• Expanding the approval of crizotinib to include patients with ROS1 will require flexibility and ongoing conversations with the FDA