# ROS1 fusion (ROS1-positive)

Source: https://onco.cc/biomarkers/ros1-fusion/  
OnCo record `ros1-fusion` (Biomarker). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

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.

## Fields

- Kind: Biomarker
- Last checked: 2026-09-23
- Also known as: ROS1 fusion; ROS1 rearrangement; ROS1-positive; ROS1+; CD74-ROS1; CD74::ROS1
- Tags: biomarker; fusion

## Sources

- Rozlytrek prescribing information (DailyMed): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c7c71b0c-2549-4495-86b6-c2807fa54908
- IBTROZI prescribing information (DailyMed): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=51ac8e52-3269-4102-8dc8-dba22d82128c

## Connected records

- biomarkers: [ALK fusion (ALK-positive)](https://onco.cc/biomarkers/alk-fusion/), [NTRK1/2/3 gene fusion](https://onco.cc/biomarkers/ntrk-fusion/), [RET fusion and RET mutation](https://onco.cc/biomarkers/ret-fusion/)
- cancers: [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/)
- drugs: [Crizotinib](https://onco.cc/drugs/crizotinib/), [Entrectinib](https://onco.cc/drugs/entrectinib/), [FoundationOne CDx / Liquid CDx](https://onco.cc/drugs/foundationone-cdx/), [Oncomine Dx Target Test](https://onco.cc/drugs/oncomine-dx-target-test/), [Repotrectinib](https://onco.cc/drugs/repotrectinib/), [Taletrectinib](https://onco.cc/drugs/taletrectinib/)
- terms: [Gene fusion](https://onco.cc/terms/gene-fusion/), [Tyrosine kinase inhibitor (TKI)](https://onco.cc/terms/tki-term/)
- targets: [ROS1](https://onco.cc/targets/ros1/)

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JSON: https://onco.cc/api/v1/entities/ros1-fusion.json