{"entity":{"id":"ros1-fusion","kind":"biomarker","name":"ROS1 fusion (ROS1-positive)","aka":["ROS1 fusion","ROS1 rearrangement","ROS1-positive","ROS1+","CD74-ROS1","CD74::ROS1"],"tldr":"A ROS1 fusion drives about 1 to 2 percent of lung adenocarcinomas and behaves much like ALK. Crizotinib, entrectinib, repotrectinib and taletrectinib are approved for it.","summary":"ROS1 rearrangements (partners include CD74, SLC34A2 and EZR) are detected by FISH, IHC or sequencing; the FDA list carries the Oncomine Dx Target Test for crizotinib and FoundationOne CDx and Liquid CDx for entrectinib. Crizotinib was the first drug labelled for ROS1-positive metastatic NSCLC (2016); entrectinib (2019) and repotrectinib (2023) followed, the latter with activity after prior ROS1 inhibitors and against the G2032R solvent-front mutation; taletrectinib (Ibtrozi, 2025) is labelled for locally advanced or metastatic ROS1-positive NSCLC without a named test requirement.","asOf":"2026-09-23","links":[{"label":"Rozlytrek prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c7c71b0c-2549-4495-86b6-c2807fa54908"},{"label":"IBTROZI prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=51ac8e52-3269-4102-8dc8-dba22d82128c"}],"tags":["biomarker","fusion"],"related":["alk-fusion","ntrk-fusion"],"cancers":["nsclc"],"sections":[],"technologies":[],"targets":[],"drugs":["crizotinib","entrectinib","repotrectinib","taletrectinib","oncomine-dx-target-test","foundationone-cdx"],"companies":[],"institutions":[],"pathways":[],"terms":["gene-fusion","tki-term"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"target":"ros1","measurement":"sequencing-variant","scoringRule":{"text":"A ROS1 gene fusion or rearrangement by FISH, immunohistochemistry confirmed by a molecular method, or DNA or RNA sequencing of tissue or plasma.","quote":"ROS1 fusions","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools","sourceLabel":"FDA: List of FDA-Authorized Companion Diagnostic Devices"},"thresholds":[{"value":"ROS1-positive","drugId":"entrectinib","cancerId":"nsclc","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c7c71b0c-2549-4495-86b6-c2807fa54908","quote":"Adult patients with ROS1- positive metastatic non-small cell lung cancer (NSCLC) as detected by an FDA-approved test.","status":"current"},{"value":"ROS1-positive","drugId":"repotrectinib","cancerId":"nsclc","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=fb526827-40ba-4462-94cf-179ae3b0cb8a","quote":"adult patients with locally advanced or metastatic ROS1- positive non-small cell lung cancer (NSCLC).","status":"current"},{"value":"ROS1-positive","drugId":"taletrectinib","cancerId":"nsclc","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=51ac8e52-3269-4102-8dc8-dba22d82128c","quote":"IBTROZI ® (taletrectinib) is indicated for the treatment of adult patients with locally advanced or metastatic ROS1 -positive non-small cell lung cancer (NSCLC)","status":"current"},{"value":"ALK or ROS1-positive","drugId":"crizotinib","cancerId":"nsclc","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2a51b0de-47d6-455e-a94c-d2c737b04ff7","quote":"whose tumors are anaplastic lymphoma kinase (ALK) or ROS1-positive as detected by an FDA-approved test.","status":"current"}],"tests":["foundationone-cdx","foundationone-liquid-cdx","guardant360-cdx","tempus-xt","trusight-oncology-comprehensive"],"assays":["oncomine-dx","foundationone-cdx-panel","foundationone-liquid-cdx"],"companionDiagnostics":[{"device":"Oncomine Dx Target Test","maker":"Life Technologies (Thermo Fisher Scientific)","companyId":"thermo-fisher","drugs":["crizotinib"],"indication":"Non-Small Cell Lung Cancer (NSCLC) - Tissue","pma":"P160045 (06/22/2017)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"},{"device":"FoundationOne CDx","maker":"Foundation Medicine","companyId":"foundation-medicine","drugs":["entrectinib"],"indication":"Non-Small Cell Lung Cancer (NSCLC) - Tissue","pma":"P170019/S014 (06/07/2022)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"},{"device":"FoundationOne Liquid CDx","maker":"Foundation Medicine","companyId":"foundation-medicine","drugs":["entrectinib"],"indication":"Non-Small Cell Lung Cancer (NSCLC) - Plasma","pma":"P190032/S004 (12/22/2022)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"}],"forPatient":"A ROS1 fusion means a ROS1 tablet (repotrectinib, taletrectinib, entrectinib or crizotinib) is the first treatment for advanced lung cancer, with the newer drugs preferred where brain spread is a concern. If the tumour later grows, a second ROS1 inhibitor may still work depending on the resistance mutation found."},"route":"/biomarkers/ros1-fusion/","neighbours":{"biomarker":[{"id":"alk-fusion","kind":"biomarker","name":"ALK fusion (ALK-positive)","route":"/biomarkers/alk-fusion/"},{"id":"ntrk-fusion","kind":"biomarker","name":"NTRK1/2/3 gene fusion","route":"/biomarkers/ntrk-fusion/"},{"id":"ret-fusion","kind":"biomarker","name":"RET fusion and RET mutation","route":"/biomarkers/ret-fusion/"}],"cancer":[{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"}],"drug":[{"id":"crizotinib","kind":"drug","name":"Crizotinib","route":"/drugs/crizotinib/"},{"id":"entrectinib","kind":"drug","name":"Entrectinib","route":"/drugs/entrectinib/"},{"id":"foundationone-cdx","kind":"drug","name":"FoundationOne CDx / Liquid CDx","route":"/drugs/foundationone-cdx/"},{"id":"oncomine-dx-target-test","kind":"drug","name":"Oncomine Dx Target Test","route":"/drugs/oncomine-dx-target-test/"},{"id":"repotrectinib","kind":"drug","name":"Repotrectinib","route":"/drugs/repotrectinib/"},{"id":"taletrectinib","kind":"drug","name":"Taletrectinib","route":"/drugs/taletrectinib/"}],"term":[{"id":"gene-fusion","kind":"term","name":"Gene fusion","route":"/terms/gene-fusion/"},{"id":"tki-term","kind":"term","name":"Tyrosine kinase inhibitor (TKI)","route":"/terms/tki-term/"}],"target":[{"id":"ros1","kind":"target","name":"ROS1","route":"/targets/ros1/"}]}}