An FDA advisory panel voted 7-2, with one abstention, on Wednesday, Sept. 23, that a blood test screening for signals from more than 50 cancer types offers more potential benefit than risk. The recommendation covers GRAIL Inc.’s Galleri test, a liquid biopsy built to catch cancer-specific DNA methylation patterns in a single blood draw. A panel vote is not an approval — the Food and Drug Administration is not bound by it, and a final decision on Galleri is still pending.
A 7-2 vote inside FDA’s genetics panel
The vote came from the Molecular and Clinical Genetics Panel of the FDA’s Medical Devices Advisory Committee, a group of oncologists, geneticists and patient representatives who met at the agency’s White Oak campus to weigh GRAIL’s premarket approval application for Galleri. A premarket approval is the FDA’s most rigorous device pathway, requiring evidence that a product’s benefits outweigh its risks for its intended use, the same standard the panel was asked to apply. Panel members split sharply on how confident they felt in the underlying evidence even as most ultimately sided with the company. “Perhaps my yes is a hopeful rather than an accurate one,” said Dr. Victor van Berkel, a University of Louisville physician on the panel, summing up the ambivalence in the room.
The panel’s actual charge, laid out in FDA’s questions to the group, was whether Galleri’s overall benefits outweigh its risks for early cancer detection — and the panel’s 7-2 vote, with one abstention, answered yes. Diana Zuckerman of the National Center for Health Research argued the risk side is easy to underestimate: “When they start having symptoms there will be tendency to delay going to the doctor,” she said of patients who test negative on Galleri and skip other screening as a result.
Galleri’s one-in-three catch rate, and its false alarms
GRAIL’s primary study behind this week’s vote followed roughly 140,000 older adults and found the test detected about one-third of the cancers diagnosed among that group over a one-year period. The test still missed roughly two-thirds of the cancers diagnosed among the same participants, a gap panel members weighed against its promise for cancer types with no dedicated screening tool today.
About two-thirds of the “cancer signal detected” results in that same study were later confirmed as cancer, meaning roughly one in three positive Galleri results was a false alarm that required follow-up imaging or biopsy before being ruled out. That rate is separate from GRAIL’s PATHFINDER 2 study, a 35,000-person trial in which Galleri delivered a 6.5-fold increase in cancer detection when layered onto standard screening — a result GRAIL has promoted even as its own materials state the test has not been cleared or approved by the Food and Drug Administration.
PATHFINDER 2 also reported 99.6% specificity and a 60.3% positive predictive value for a flagged signal, figures that describe a different, additive-screening population than the roughly 140,000-person study the panel actually reviewed this week. The mismatch shows that GRAIL’s various trials produce different-looking numbers depending on who was tested and how the test was used alongside existing screening.
Cancers with no screening test today
Part of Galleri’s appeal to the panel is where it can catch disease earlier than any existing test. The blood draw screens for signals from more than 50 cancer types, including liver and ovarian cancer, for which no routine screening option exists in current guidelines, by reading cancer-specific DNA methylation patterns shed into the bloodstream.
Liver and ovarian cancer are both typically caught late, once symptoms have already appeared and treatment options have narrowed — the exact gap multi-cancer screening is designed to close before it opens.
GRAIL’s next stop: a premarket approval decision
An advisory committee vote does not equal marketplace clearance. The FDA will weigh the panel’s input against GRAIL’s premarket approval application for Galleri, but the agency is not required to follow the recommendation and can still request more data or reject the application outright, according to the executive summary the agency prepared for the meeting.
Dr. Mylynda Massart, a University of Pittsburgh physician who represented GRAIL’s perspective on the panel, framed the stakes in terms of patients rather than regulators: “Patients want opportunity, they want options,” she said. If Galleri does win approval, the test would likely qualify for Medicare and private insurer coverage, opening it to a far broader pool of adults than the number who have already paid out of pocket to take it.
A final FDA decision on Galleri is expected within the next few months, on the agency’s own timeline for the review. Until then, the panel’s Molecular and Clinical Genetics Panel vote stands as a recommendation, not a clearance — and the one-in-three false-positive rate is the number the agency’s own reviewers still have to weigh against everything Galleri promises to catch early.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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