# Tempus xR

Source: https://onco.cc/drugs/tempus-xr/  
OnCo record `tempus-xr` (Test). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A tumour RNA sequencing test from Tempus, usually run with its DNA panel, that finds gene fusions DNA testing can miss.

## Summary

The FDA cleared xR IVD (510(k) K241868, Tempus AI) on 19 September 2025 for the "detection of rearrangements in two genes, using RNA isolated from formalin-fixed paraffin embedded (FFPE) tumor tissue specimens from patients with solid malignant neoplasms", BRAF and RET; the FDA summary adds that results "are not intended to be prescriptive or conclusive for labeled use of any specific therapeutic product". In the FDA summary, agreement was 100 per cent for RET (13 of 13 positive) and 92.3 per cent for BRAF (12 of 13). A Tempus study describes xR as "a whole-transcriptome RNA-seq assay" and, in 67,278 patients who had both RNA and DNA sequencing, found that adding RNA increased detection of driver gene fusions by 21 per cent over DNA alone (Gai 2025). The maker's page could not be read.

## Fields

- Kind: Test
- Status: approved
- Last checked: 2026-11-04
- Also known as: Tempus xR IVD; xR IVD
- Tags: test; rna
- Brand: xR
- Modality: Tumour RNA sequencing test (fusion detection; FDA-cleared for BRAF and RET rearrangements)
- Mechanism: RNA from fixed tumour tissue is captured with a whole-exome probe set plus custom probes and sequenced; the FDA-cleared version reports rearrangements in BRAF and RET.
- Approvals: US 2025: FDA 510(k) clearance (K241868) for detection of BRAF and RET rearrangements in RNA from solid tumour tissue

## Sources

- FDA 510(k) K241868: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K241868
- FDA decision summary K241868: https://www.accessdata.fda.gov/cdrh_docs/reviews/K241868.pdf

## Connected records

- drugs: [Archer FusionPlex panels](https://onco.cc/drugs/archer-fusionplex/), [FoundationOne RNA](https://onco.cc/drugs/foundationone-rna/), [Tempus xE](https://onco.cc/drugs/tempus-xe/), [Tempus xT CDx](https://onco.cc/drugs/tempus-xt-cdx/)
- technologies: [Comprehensive genomic profiling](https://onco.cc/technologies/cgp/), [RNA sequencing & expression profiling](https://onco.cc/technologies/rna-seq/)
- companies: [Tempus AI](https://onco.cc/companies/tempus/)
- key papers: [Molecular Characterization of Oncogenic Gene Fusions in a Large Real-World Cohort of Solid Tumors](https://onco.cc/key-papers/paper-gai-rna-dna-ngs-fusions-cancer-res-commun-2025/)

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