ROS1 fusions occur when a portion of the ROS1 gene is swapped (or fused) with a portion of another gene. The fusion gene then produces an abnormal ROS1 protein that makes the cell behave like cancer. Tumors that are driven by ROS1 fusions are called ROS1-positive or ROS1+ cancer. It occurs in 1% to 2% of non-small cell lung cancers as well as many other solid tumors.
Targeted therapy drugs bind with the abnormal ROS1 protein and block its signals so the cell no longer behaves like cancer. Since the cell is addicted to the signaling of the abnormal ROS1 protein, the cell dies when the ROS1 signaling is blocked.
The oral targeted therapy entrectinib (brand name Rozlytrek) is FDA-approved for treating ROS1+ cancer for non-small cell lung cancer, but it is not approved for other types of cancer. This means many patients with other ROS1+ solid tumors might not be able to access the drug outside of a clinical trial.
For people living with ROS1+ cancer other than lung cancer, and who have run out of treatment options, the TAPUR (Targeted Agent and Profiling Utilization Registry) clinical trial may be a good option. The TAPUR Study is a phase II, nonrandomized clinical trial that targets ROS1+ cancer with entrectinib. Since the drug is taken orally, patients can take it at home instead having an infusion at the clinic, and many patients find oral targeted therapies are more tolerable than chemotherapy.
The TAPUR Study has over 250 clinical sites across 28 states in the United States. For more information on the TAPUR Study, visit the TAPUR website at www.TAPUR.org. If you would like to learn more, the study team recently held a virtual live Grand Rounds which was recorded. The May 2023 TAPUR Grand Rounds recording is available for viewing and can be found under the “Study Results” page of the TAPUR website.