FDA Approves Guardant360 CDx as Companion Diagnostic for BRAF V600E Metastatic Colorectal Cancer - GNTX

The U.S. Food and Drug Administration approved Guardant Health’s Guardant360 CDx as a companion diagnostic test for identifying patients with BRAF V600E-mutated metastatic colorectal cancer eligible for treatment with encorafenib and cetuximab. The approval, issued on January 22, 2026, supports the use of the liquid biopsy test to detect the genetic mutation in plasma samples. Guardant360 CDx is a next-generation sequencing-based assay designed to identify actionable genomic alterations in non-invasive blood samples. The FDA clearance aligns with clinical trial data showing improved outcomes when targeted therapy is guided by molecular profiling. The test will be used alongside the combination regimen developed by Amgen and Array BioPharma, which demonstrated efficacy in patients with this specific mutation. This marks the first FDA-approved liquid biopsy companion diagnostic for BRAF V600E in metastatic colorectal cancer. Guardant Health (GNTX) shares rose 4.7% following the announcement, reflecting investor optimism over expanded commercial opportunities in oncology diagnostics.