Tempus AI has announced the nationwide commercial availability of its next-generation sequencing (NGS)-based diagnostic test, xT CDx, marking a significant advancement in precision oncology. The 648-gene assay, which received FDA approval in May 2023, provides comprehensive genomic profiling for solid tumors, including microsatellite instability status assessment.
"We are thrilled to broadly introduce our xT CDx test, which combines the trusted performance our clinicians rely on, now with FDA approval," said Dr. Ezra Cohen, Chief Medical Officer of Oncology at Tempus AI. He emphasized the company's commitment to delivering high-quality, actionable insights to improve patient outcomes.
Technical Capabilities and Applications
The xT CDx test analyzes DNA isolated from FFPE tumor tissue samples alongside matched normal blood or saliva samples from patients with solid malignant neoplasms. It detects various genetic alterations, including single nucleotide variants (SNVs), multi-nucleotide variants (MNVs), and insertion/deletion alterations across 648 genes.
Notably, the test serves as a companion diagnostic for colorectal cancer (CRC) treatment selection, identifying:
- KRAS wild-type patients who may benefit from cetuximab (Erbitux)
- KRAS and NRAS wild-type patients who could be candidates for panitumumab (Vectibix)
Robust Clinical Validation
The test's validation study encompassed 416 samples across 31 different tumor types, with significant representation from:
- Colorectal cancer (69 samples)
- Breast cancer (44 samples)
- Ovarian cancer (38 samples)
- Glioblastoma (34 samples)
- Non-small cell lung cancer (29 samples)
Performance metrics demonstrated exceptional accuracy in variant detection:
- 98.9% positive percent agreement (95% CI, 96.2%-99.9%)
- 100% negative percent agreement (95% CI, 100.0%-100%) for hotspot variants
- 100% positive percent agreement (95% CI, 88.8%-100.0%) for CDx-specific KRAS and NRAS variants in CRC
Advanced Technical Features
A key advantage of xT CDx is its use of matched normal samples, which enabled the reclassification of 148 variants previously identified as somatic to germline alterations. This capability enhances the accuracy of tumor-specific mutation identification.
The validation study specifically examined 192 variants in hotspot regions, including:
- 187 substitutions across 10 genes
- 5 insertions or deletions across 4 genes
This comprehensive testing approach provides clinicians with detailed molecular insights to guide precision medicine strategies across a broad spectrum of solid tumors.
