The U.S. Food and Drug Administration approved Guardant Health’s Guardant360 CDx as a companion diagnostic to identify BRAF V600E‑mutant metastatic colorectal cancer patients for Pfizer’s encorafenib (Braftovi) plus cetuximab and chemotherapy regimen. The approval follows data from Pfizer’s Phase 3 BREAKWATER trial showing improved response rates, progression‑free survival and overall survival in the biomarker‑positive population. Guardant framed the clearance as validation of circulating tumor DNA (ctDNA) testing in advanced oncology care and said the test will support rapid, noninvasive patient selection and resistance monitoring. Clinicians and payers will now evaluate implementation logistics and reimbursement; debate persists over the clinical utility and cost‑effectiveness of liquid biopsy vs tissue testing in colorectal cancer.