(NSCLC). However, some clinical trials (like those for entrectinib, DS-6051b, and TPX-0005) accept patients with ROS1 cancer in any type of solid tumor. Crizotinib is approved for treating metastatic ROS1-positive NSCLC in many countries. In clinical trials, crizotinib was shown to be effective for 70-80% of ROS1+ NSCLC patients, but it does not effectively treat the brain. Some patients have a response that lasts for years. Crizotinib is available to patients with solid tumors other than NSCLC through clinical trials. Entrectinib (RXDX-101) is a selective tyrosine kinase inhibitor developed by Ignyta, Inc., with specificity, at low nanomolar concentrations, for all of three Trk proteins (encoded by the three NTRK genes, respectively) as well as the ROS1, and ALK receptor tyrosine kinases. An open label, multicenter, global phase 2 clinical trial called STARTRK-2 started in 2015 to test the drug in patients with ROS1/NTRK/ALK gene rearrangements. Lorlatinib (also known as PF-06463922) was shown in an ongoing Phase 2 clinical trial to be effective in some ROS1+ NSCLC patients, and treats the cancer in the brain as well as the body. Lorlatinib has the potential to overcome certain resistance mutations that develop during treatment with crizotinib. Ceritinib demonstrates clinical activity (including treating the brain) in ROS1+ NSCLC patients who had previously received platinum-based chemotherapy. In preclinical studies, ceritinib is unable to overcome most ROS1 resistance mutations, including ROS1 G2032R. It has more severe side effects than crizotinib for some patients. Ceritinib is US FDA approved for first line treatment of ALK+ metastatic non-small cell lung cancer. TPX-0005 preclinical data suggests it is a potent inhibitor of ROS1+ cancer. A Phase I clinical trial opened in March 2017 for patients with advanced solid tumors harboring ALK, ROS1, or NTRK1-3 rearrangements. DS-6051b preclinical data show it is active against ROS1-positive cancers. It is an ongoing clinical trial. Cabozantinib preclinical data has shown the drug might overcome crizotinib resistance in ROS1+ cancer in early studies. However, the required dosage makes the drug difficult to tolerate for many patients. Cabozantinib is US FDA approved for metastatic medullary thyroid cancer (as Cometriq) and renal cell carcinoma (as Cabometyx). The ROS1ders The ROS1ders is a worldwide collaboration of ROS1+ cancer patients and caregivers with a goal of improving patient outcomes and accelerating research for any type of ROS1+ cancer. It is the first such collaboration focused on cancers driven by a single oncogene. Their website tracks targeted therapies,