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# FDA OKs Guardant360 CDx Companion Diagnostic
- URL: https://www.fdaweb.com/fda-oks-guardant360-cdx-companion-diagnostic/
- Published: 2026-01-23T12:00:00.000Z
- Updated: 2026-09-14T15:31:22.000Z
- Author: David McFarland
- Tags: Devices, #legacy-id-D5160538

FDA has approved Guardant Health’s Guardant360 CDx liquid biopsy as a companion diagnostic to identify patients with BRAF V600E–mutant metastatic colorectal cancer who may benefit from treatment with Pfizer’s Braftovi (encorafenib) in combination with cetuximab (Lilly’s Erbitux) and chemotherapy. The decision was supported by data from Pfizer’s Phase 3 BREAKWATER trial, which evaluated encorafenib-based regimens in previously untreated patients with BRAF-mutated metastatic colorectal cancer.

According to Guardant Health, the BREAKWATER study showed that treatment with encorafenib plus cetuximab and mFOLFOX6 chemotherapy significantly improved objective response rate, progression-free survival and overall survival compared with standard of care. The results underscore the clinical value of early genomic testing to guide treatment selection in this aggressive subtype of colorectal cancer.

Guardant360 CDx uses a blood-based liquid biopsy to detect BRAF V600E and other clinically relevant genomic alterations from circulating tumor DNA, enabling non-invasive testing when tumor tissue is unavailable, insufficient or when rapid treatment decisions are needed. The company says the approval expands access to precision medicine for a high-risk patient population and supports broader adoption of liquid biopsy in routine oncology care.