Caris Life Sciences has achieved a significant milestone in precision oncology with the FDA approval of MI Cancer Seek, marking the first simultaneous whole exome sequencing (WES) and whole transcriptome sequencing (WTS)-based companion diagnostic test for solid tumors. The comprehensive molecular profiling assay is approved for both adult and pediatric patients aged 1-22, addressing a critical need for detailed genetic insights in cancer treatment selection.
Comprehensive Molecular Profiling Capabilities
MI Cancer Seek represents a breakthrough in diagnostic efficiency by combining DNA and RNA analysis into a single workflow. The test analyzes total nucleic acid isolated from formalin-fixed paraffin-embedded (FFPE) tumor tissue specimens to detect single nucleotide variants and insertions/deletions in 228 genes, microsatellite instability (MSI), tumor mutational burden (TMB), and copy number amplification in breast cancer patients.
According to research published in Oncotarget, the assay demonstrated remarkable performance with minimal tissue requirements. "MI Cancer Seek demonstrated strong concordance with other FDA-approved companion diagnostics and serves as a powerful tool to guide treatment decisions in both adult and pediatric cancer patients," stated the study authors from Caris Life Sciences.
Clinical Validation and Performance
The test achieved exceptional accuracy in clinical validation studies, showing over 97% agreement with other FDA-approved diagnostic tools. Notably, it maintained high precision in detecting critical biomarkers including PIK3CA, EGFR, BRAF, and KRAS/NRAS mutations from samples as small as 50 ng of tissue input.
The assay demonstrated near-perfect accuracy in identifying MSI status in colorectal and endometrial cancers, crucial indicators for immunotherapy response. Even when analyzing degraded FFPE samples, which are widely used in clinical practice, the test maintained high levels of accuracy across different laboratory conditions and varying DNA input levels.
Companion Diagnostic Indications
MI Cancer Seek includes one pan-cancer and five tumor-specific companion diagnostic indications for numerous FDA-approved targeted therapies. The test covers major cancer types including breast, lung, colon, melanoma, and endometrial cancers, providing comprehensive biomarker identification to guide treatment decisions.
The assay is intended as a companion diagnostic to identify patients who may benefit from treatment with specific targeted therapies, including PIQRAY, VECTIBIX, BRAFTOVI, ERBITUX, MEKINIST, KEYTRUDA, and LENVIMA, in accordance with approved therapeutic product labeling.
Advanced Features and Clinical Impact
Beyond its companion diagnostic capabilities, MI Cancer Seek incorporates advanced features developed under its predecessor, MI Tumor Seek Hybrid. These include detection of homologous recombination deficiency, structural variants, and cancer-related viruses. The test also features a Genomic Probability Score for identifying tissue of origin in cancers of unknown primary and gene signatures to guide first-line chemotherapy in colorectal cancer.
"We are very excited to receive FDA approval for our MI Cancer Seek test. The extensive rigor with which the FDA evaluates new technology ensures patients have access to safe and effective tests," said Caris President David Spetzler.
Study Limitations and Future Implications
The research identified one limitation: "low PPA for ERBB2 CNA detection," which researchers noted should be considered in clinical applications.
By offering comprehensive genetic insights from a single, small sample, MI Cancer Seek has the potential to streamline diagnostics, reduce testing costs, and connect patients to effective therapies more quickly. As precision medicine continues to expand, this FDA-approved assay represents a significant advancement in meeting the evolving needs of modern oncology practice.
