Guardant360 CDx

Overview

Guardant360 CDx is a commercially available cell-free DNA (cfDNA) liquid biopsy panel developed by Guardant Health. It interrogates 74–83 genes (assay versions differ) from circulating tumor DNA (ctDNA) in plasma using targeted next-generation sequencing. The panel covers oncogenic mutations, copy number amplifications, and selected fusions, and has FDA breakthrough device designation for multiple solid tumor indications. It is used for both molecular profiling and longitudinal resistance monitoring without the need for invasive tissue biopsy.

Used by

• Used for ctDNA profiling of patients 1–5 and 11 in a 12-patient KRASG12C-mutant colorectal cancer cohort treated with combined KRAS/EGFR inhibition; detected heterogeneous acquired resistance alterations including KRAS switch mutations, NRAS mutations, BRAF mutations/fusions, MET amplification, and RET fusions, all at low variant allele frequency PMID:36355783

Notes

• Coverage is gene-panel-based (74–83 genes depending on assay version); does not provide whole-exome or whole-genome coverage.
• ctDNA input may limit sensitivity for detecting low-shedding tumors or alterations at very low allele frequency.
• In the KRASG12C CRC cohort, Guardant360 CDx was used alongside MSK-IMPACT (tissue/cell line) and MSK-ACCESS (patient 12 ctDNA), illustrating multi-platform longitudinal resistance tracking.

Sources

• PMID:36355783 — Acquired resistance to KRAS/EGFR co-inhibition in KRASG12C-mutant CRC; Guardant360 CDx used for serial ctDNA profiling.

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