STAT+: Grail says new data on multi-cancer screening test show improved performance

In a strategic effort to redefine cancer screening and establish dominance in a growing competitive landscape, Grail unveiled recent findings on Friday from an extensive U.S. study concerning its leading blood test designed for the detection of multiple tumor types. These results bolster the company’s case for a novel screening method; however, experts caution that pivotal questions about the test’s implications in real-world settings remain unanswered.

The Pathfinder 2 study included nearly 36,000 participants aged 50 and above to assess the performance of Galleri, the biotech’s screening tool. When analyzing the results in individuals who had been monitored for over a year, researchers determined that the test identified 40.4% of cancer cases, a metric known as sensitivity. Over half of the diagnosed cancers were detected in the early stages, specifically stages 1 or 2, and roughly 75% of these cases fall outside the scope of current screening practices, including cancers of the pancreas, liver, and head and neck.

Regarding those who received a positive test result, almost 62% were confirmed to have cancer, while 38% were false positives. Previous research on Galleri indicated a slightly lower positive predictive value, ranging from 43% to 50%.