Multi-Cancer Early Detection Blood Test Increases Cancer Detection

Cancer is the second leading cause of death worldwide as most deadly cancers are found too late. Approximately 70% of cancer deaths come from cancers that do not have standard-of-care screening and are typically caught too late. Now, new study findings reveal a multi-cancer early detection blood test yielded a more than seven-fold increase in the cancer detection rate and found many cancers at earlier, more treatable stages.

GRAIL, Inc.’s (Menlo Park, CA, USA) Galleri multi-cancer early detection (MCED) test is a targeted methylation–based blood test that can detect more than 50 types of cancer from a simple blood draw. PATHFINDER 2 is a prospective, multi-center, interventional study conducted in the United States and Canada that enrolled approximately 35,878 adults aged 50 and older who were eligible for guideline-recommended cancer screening. Results reported here come from a pre-specified analysis of the first 25,578 participants with at least 12 months of follow-up; of these, 23,161 were analyzable for performance and 25,114 for safety.

In the performance analyzable cohort, the test detected a cancer signal in 216 participants (cancer signal detection rate 0.93%), and cancer was diagnosed in 133 participants (cancer detection rate 0.57%), yielding a positive predictive value of 61.6%. Episode sensitivity was 73.7% for the 12 cancers responsible for two-thirds of U.S. cancer deaths and 40.4% for all cancers; specificity was 99.6% (false positive rate 0.4%). More than half (53.5%) of the new cancers detected were stage I or II and the test correctly identified the cancer signal origin 92% of the time; these PATHFINDER 2 results were presented at the ESMO Congress.

Adding the Galleri test to recommended screening found more cancers earlier and detected many cancers that do not have standard-of-care screening options, suggesting the test could fundamentally change population-level screening approaches. Diagnostic evaluation after a positive test had a median resolution of 46 days and only 0.6% of all participants underwent an invasive procedure during workup, with no serious study-related adverse events reported. Data from this study will be submitted to the U.S. Food and Drug Administration as part of a premarket approval application, with GRAIL expecting to complete the PMA modular submission in the first half of 2026.

“These results are extremely compelling as approximately three-quarters of the Galleri-detected cancers do not have recommended screening tests today. Galleri is the only MCED test available that has been validated in an interventional trial in the screening population and could transform how we deliver cancer screening at a population level,” said Josh Ofman, MD, MSHS, President, GRAIL, Inc.; spokesperson and company lead on the PATHFINDER 2 program.

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