Tempus xF Monitor

Tempus has launched the research-use-only xF Monitor circulating tumor DNA test for the detection and monitoring of changes in circulating tumor fraction to determine early response to immunotherapy for patients with advanced cancers. The test analyzes diverse genomic events, dynamically weighting somatic variant allele frequencies and copy number variants, while using germline information to inform these estimates, Tempus said. The algorithm that powers the test — xF ctDNA tumor fraction — uses multiple single input models and weights their importance based on failure modes observed in Tempus' multimodal database, the company said. The algorithm can be used with Tempus' 105-gene liquid assay, xF, and its 523-gene liquid assay, xF+.