Guardant Health's Breast Cancer Diagnostic Approved by US FDA

06:08 AM EDT, 09/08/2026 (MT Newswires) -- Guardant Health's (GH) Guardant360 CDx has been approved by the US Food and Drug Administration as a companion diagnostic for advanced metastatic breast cancer, the company said Friday. The specific indication for the diagnostic combination is to identify patients with hormone receptor-positive, HER2-negative advanced or metastatic breast cancer harboring tumors with specific mutations before radiographic progression who may benefit from treatment with AstraZeneca's (AZN) Etcamah, the company said. The approval is based on data from a clinical trial showing a 56% reduction in the risk of progression or death, the company said. Shares of the company were up 1% in recent premarket trading.