Biodesix expanded its collaboration with Bio‑Rad to develop, clinically validate and seek regulatory clearance for cancer in vitro diagnostic assays using Bio‑Rad’s QX600 Droplet Digital PCR platform. The first assay to be validated is a multiplex ddPLEX ESR1 mutation test for ctDNA detection in advanced HR+/HER2‑ breast cancer. Under the agreement Biodesix will develop and manufacture specimen collection kits and pursue reimbursement with CMS following regulatory clearance. The companies said the assay will support both biopharma customers developing targeted therapies and clinical monitoring for treatment selection, reflecting rising demand for sensitive liquid‑biopsy tools. The deal underscores a market pivot toward decentralized, high‑sensitivity ctDNA testing that can guide targeted therapy selection and accelerate drug development decisions.