FDA advisers voted 7-2, with one abstention, that the benefits of Grail’s Galleri multicancer blood test outweigh its risks, marking a significant step toward potential FDA approval. The test, which requires a single blood draw, analyzes methylation patterns in cell-free DNA to detect cancer signals and identify associated tissue types.
FDA Panel Backs Grail’s Galleri Test
The molecular and clinical genetics panel at the FDA unanimously agreed the test is safe, though its effectiveness endorsement passed narrowly with six votes in favor and four against. Panel members emphasized the test should not replace existing guideline-recommended screenings for breast, cervical, colorectal, and lung cancers.
“The biggest concerns, as we’ve talked about, are people being falsely reassured and not getting recommended screening, and then the very small number of people who have a false positive, and the exposure they get to [follow-up] testing,” said Deborah Armstrong, professor of oncology at Johns Hopkins School of Medicine. “But if people are well informed, I think that’s acceptable.”
The panel debated extensively over false positive and negative results, ultimately deeming the risk of false positives low. However, concerns remained about patients receiving negative results potentially skipping proven screening methods.
Real-World Impact and Limitations
Kevin McFarland, a retired Ohio firefighter, shared at the meeting that the Galleri test detected his esophageal cancer at stage 1. “To have this test catch my cancer that early, it truly saved my life,” McFarland said.
Despite individual success stories, panel members expressed caution about limited data on the test’s reliability for detecting certain cancer types. Charity Morgan, professor of biostatistics at the University of Alabama, noted, “We don’t have the evidence in front of us today to say this test can detect those types of cancers, and until we do, I don’t think we can say that Galleri can detect those cancers.”
Grail highlighted that its data shows the test detects four to seven times more cancers compared to standard care alone, while also shifting detection toward earlier stages of disease. The company emphasized Galleri is intended for use alongside, not as a replacement for, guideline-recommended screenings. Grail began selling the test as a laboratory-developed test in 2021, a regulatory pathway that does not require FDA approval.
The FDA typically follows its expert panels’ recommendations, and analysts at Canaccord Genuity called this vote “a solid predictor of FDA approval.” No FDA-authorized devices currently screen for multiple cancer types simultaneously.
