Guardant Health received FDA approval for its Guardant360 CDx liquid biopsy as a companion diagnostic for identifying BRAF V600E‑mutant metastatic colorectal cancer patients eligible for Pfizer’s encorafenib plus cetuximab and chemotherapy regimen. The decision was supported by data from Pfizer’s Phase III BREAKWATER trial, which showed improved response, PFS and overall survival with the targeted combination. The approval expands Guardant360’s companion diagnostic footprint and underscores growing regulatory acceptance of ctDNA assays for treatment selection. Clinical labs and oncology practices will assess how to integrate plasma genotyping into frontline therapy decisions and resistance monitoring workflows.