Cancer Research UK, the Royal Marsden NHS Foundation Trust, and Guardant Health said they will make circulating tumor DNA (ctDNA) testing freely available for hundreds of patients with advanced solid tumors. The effort is tied to an ECMC network initiative aimed at expanding genomic testing capacity across the UK. Under the collaboration, CRUK plans to fund a proof-of-concept program to provide at least 500 Guardant360 Liquid CDx tests. The assay analyzes genomic and epigenomic markers in patient ctDNA to identify actionable mutations that can guide targeted therapy decisions. Guardant360 Liquid CDx recently received FDA approval, and the partners said the expanded testing will also support precision medicine trials involving ctDNA profiling, including those led by CRUK’s Centre for Drug Development.