Screen time for Guardant

Guardant Health, first to market with a pan-cancer liquid biopsy, is also the first to launch a blood test to screen for colorectal cancer. The Shield assay, formerly called Lunar-2, went on sale yesterday in the US as a homebrew test to detect colorectal cancer in average-risk people aged 45 and older. Sales are unlikely to be stratospheric at first: the vast Eclipse trial, designed to support FDA approval of the test in this setting, has not yet reported – the data might come at Asco next month. Approval for Shield, should it be granted, ought to allow sales-boosting reimbursement and guideline changes, though guidelines are unlikely to be updated before 2026, according to Stifel analysts. At that point Shield would amount to a major threat to Exact Sciences’ Cologuard stool test, currently the leading non-invasive colorectal screen. In advance of the Eclipse readout, Guardant released new data from a smaller study indicating that Shield’s sensitivity and specificity for detecting cancer were 91% and 92% respectively – competitive with Cologuard and the clinical-stage second-gen version of that test. Guardant is also investigating Shield as a screen for lung, pancreatic and bladder cancers, but for now all the attention remains on Eclipse.