Esmo 2022 – Exact trails Grail on sensitivity

Exact Sciences spent $1.7bn on Thrive in 2020 to get its hands on that company’s liquid biopsy, then called CancerSeek. Data presented on Friday at Esmo, however, suggest that this assay, which Exact now refers to simply as its multi-cancer early detection (MCED) test, might not be quite as good as the competition. The data come from a retrospective, case-control study intended to validate four blood biomarkers – aneuploidy, DNA methylation, mutations and proteins – detected by the assay. They indicated that the test could detect cancers from 15 organ sites with a mean sensitivity of 61% and mean specificity of 98%. But splitting the data by stage of the cancer suggests that Exact’s assay might not be quite as sensitive as Grail/Illumina’s Galleri pan-cancer test was in a similar trial, as the graph below shows. This is not a strictly fair juxtaposition, of course, since cross-trial comparisons never are; moreover the tests picked up different tumour types, which will have affected their accuracy figures. Exact is currently conducting a larger case-control trial, results of which will determine the final design of the MCED test, which will next year go into a pivotal US study called Soar.