{"entity":{"id":"ret-fusion","kind":"biomarker","name":"RET fusion and RET mutation","aka":["RET fusion","RET rearrangement","RET fusion-positive","KIF5B-RET","KIF5B::RET","CCDC6-RET","RET mutation","RET M918T","RET-mutant medullary thyroid cancer","RET-altered"],"tldr":"RET fusions drive 1 to 2 percent of lung cancers and some thyroid cancers; RET point mutations drive medullary thyroid cancer. Selpercatinib is approved for RET fusions in any solid tumour and for RET-mutant medullary thyroid cancer; pralsetinib for RET fusion lung cancer.","summary":"RET fusions (KIF5B::RET, CCDC6::RET, NCOA4::RET) are detected by RNA or DNA sequencing and FISH; RET point mutations (M918T, codon 634 and others, germline in MEN2) by sequencing. Selpercatinib (Retevmo) is labelled for RET fusion-positive NSCLC, RET fusion-positive thyroid cancer, RET-mutant medullary thyroid cancer and, since 2022, RET fusion-positive solid tumours after prior therapy, each as detected by an FDA-approved test; pralsetinib (Gavreto) for RET fusion-positive NSCLC. The Oncomine Dx Target Test, FoundationOne CDx and TruSight Oncology Comprehensive are the listed companion diagnostics.","asOf":"2026-09-23","links":[{"label":"Retevmo prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7fa848ba-a59c-4144-9f52-64d090f4d828"},{"label":"Gavreto prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=16edd46e-28b8-f06d-e063-6394a90ae31b"}],"tags":["biomarker","fusion"],"related":["alk-fusion","ntrk-fusion","ros1-fusion"],"cancers":["nsclc","thyroid","medullary-thyroid-cancer","papillary-thyroid-cancer","metastatic-cancer"],"sections":[],"technologies":[],"targets":[],"drugs":["selpercatinib","pralsetinib","oncomine-dx-target-test","foundationone-cdx","trusight-oncology-comprehensive"],"companies":[],"institutions":[],"pathways":[],"terms":["gene-fusion","tumour-agnostic","tki-term"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"target":"ret","measurement":"sequencing-variant","scoringRule":{"text":"A RET gene fusion by RNA or DNA sequencing (or FISH), or an activating RET point mutation, small deletion or insertion by sequencing.","quote":"RET fusions; RET mutations (SNVs, MNVs, and deletions)","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":"RET fusion-positive","drugId":"pralsetinib","cancerId":"nsclc","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=16edd46e-28b8-f06d-e063-6394a90ae31b","quote":"Adult patients with metastatic rearranged during transfection (RET ) fusion-positive non-small cell lung cancer as detected by an FDA approved test (NSCLC).","status":"current"},{"value":"RET fusion-positive (NSCLC, thyroid, solid tumours) and RET-mutant medullary thyroid cancer","drugId":"selpercatinib","cancerId":"medullary-thyroid-cancer","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7fa848ba-a59c-4144-9f52-64d090f4d828","status":"current","note":"Retevmo label indications 1.1 to 1.4 (DailyMed set id 7fa848ba): RET fusion-positive NSCLC, RET-mutant medullary thyroid cancer, RET fusion-positive thyroid cancer, and RET fusion-positive solid tumours after prior systemic treatment, each as detected by an FDA-approved test."},{"value":"RET fusion-positive","drugId":"selpercatinib","cancerId":"nsclc","regulator":"FDA","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools","quote":"RET fusions","status":"current","note":"FDA companion diagnostic rows for the Oncomine Dx Target Test (P160045/S031) and TruSight Oncology Comprehensive (P230011) with Retevmo in NSCLC."}],"tests":["foundationone-cdx","trusight-oncology-comprehensive","tempus-xt","guardant360-cdx","caris-mi-cancer-seek"],"assays":["oncomine-dx","foundationone-cdx-panel"],"companionDiagnostics":[{"device":"Oncomine Dx Target Test","maker":"Life Technologies (Thermo Fisher Scientific)","companyId":"thermo-fisher","drugs":["pralsetinib"],"indication":"Non-Small Cell Lung Cancer (NSCLC) - Tissue","pma":"P160045/S019 (09/04/2020)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"},{"device":"Oncomine Dx Target Test","maker":"Life Technologies (Thermo Fisher Scientific)","companyId":"thermo-fisher","drugs":["selpercatinib"],"indication":"Medullary Thyroid Cancer (MTC) - Tissue","pma":"P160045/S031 (09/21/2022)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"},{"device":"FoundationOne CDx","maker":"Foundation Medicine","companyId":"foundation-medicine","drugs":["selpercatinib"],"indication":"Solid Tumors - Tissue","pma":"P170019/S043 (10/06/2023)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"},{"device":"TruSight Oncology Comprehensive","maker":"Illumina","companyId":"illumina","drugs":["selpercatinib"],"indication":"Non-Small Cell Lung Cancer (NSCLC) - Tissue","pma":"P230011 (08/21/2024)","source":"https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools"}],"forPatient":"A RET fusion means selpercatinib (or, in lung cancer, pralsetinib) is an on-label tablet whatever the cancer type once other treatment has been tried, and first line in lung cancer. In medullary thyroid cancer a RET point mutation qualifies for selpercatinib too, and if the mutation is inherited (MEN2) relatives should be tested."},"route":"/biomarkers/ret-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":"ros1-fusion","kind":"biomarker","name":"ROS1 fusion (ROS1-positive)","route":"/biomarkers/ros1-fusion/"}],"cancer":[{"id":"medullary-thyroid-cancer","kind":"cancer","name":"Medullary thyroid cancer","route":"/cancers/medullary-thyroid-cancer/"},{"id":"metastatic-cancer","kind":"cancer","name":"Metastatic cancer (cancer that has spread)","route":"/cancers/metastatic-cancer/"},{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"},{"id":"papillary-thyroid-cancer","kind":"cancer","name":"Papillary thyroid cancer","route":"/cancers/papillary-thyroid-cancer/"},{"id":"thyroid","kind":"cancer","name":"Thyroid cancer","route":"/cancers/thyroid/"}],"drug":[{"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":"pralsetinib","kind":"drug","name":"Pralsetinib","route":"/drugs/pralsetinib/"},{"id":"selpercatinib","kind":"drug","name":"Selpercatinib","route":"/drugs/selpercatinib/"},{"id":"trusight-oncology-comprehensive","kind":"drug","name":"TruSight Oncology Comprehensive","route":"/drugs/trusight-oncology-comprehensive/"}],"term":[{"id":"gene-fusion","kind":"term","name":"Gene fusion","route":"/terms/gene-fusion/"},{"id":"tumour-agnostic","kind":"term","name":"Tumour-agnostic (tissue-agnostic) approval","route":"/terms/tumour-agnostic/"},{"id":"tki-term","kind":"term","name":"Tyrosine kinase inhibitor (TKI)","route":"/terms/tki-term/"}],"target":[{"id":"ret","kind":"target","name":"RET","route":"/targets/ret/"}]}}