FDA Panel Voted 6 to 4 That a Cancer Blood Test Works. Its Biggest Trials Missed Their Main Goal.

A Food and Drug Administration advisory panel voted 6 to 4 on Wednesday that there is reasonable assurance Grail's Galleri blood test works well enough to reach the market. It was the closest of three votes the same ten-member panel took that day on the same test. The panel voted 10 to 0 that Galleri is safe, and 7 to 2 with one abstention that its overall benefits outweigh its risks. The effectiveness vote split because Galleri's two largest clinical trials did not reduce cancer deaths and did not meet the goal they were originally designed around.

Galleri, made by the California company Grail, is a blood test built around a single kind of signal, a pattern of DNA methylation that many cancer types share. Grail says the test can flag signs of up to 50 cancer types, including several with no standard screening test today, such as pancreatic and ovarian cancer. It is already sold by prescription for $949 out of pocket. FDA approval would likely trigger Medicare coverage, since a 2024 law requires the program to cover multi-cancer detection tests once the FDA clears one.

Two large trials, one missed target

The panel reviewed two studies that anchor Grail's application: the NHS-Galleri trial, which enrolled more than 140,000 patients through England's National Health Service, and PATHFINDER 2, which enrolled more than 35,000 patients in North America. Both tracked adults 50 and older. Neither trial reduced overall cancer mortality, and neither hit its original primary endpoint, a combined reduction in Stage III and Stage IV cancer diagnoses. In a later update to the NHS-Galleri data, Grail reported that Stage IV diagnoses alone, not combined with Stage III, fell over the trial's three-year period, which the company says suggests the test is shifting some diagnoses to earlier stages.

“Routine approval and broad population rollout would risk harm and waste resources.”

Castle told the panel the available data were too preliminary to show real clinical benefit, and warned that marketing Galleri as an early detection tool could give people a false sense of security if it leads them to skip standard screening such as colonoscopies or mammograms. The panel's own recommendation carried the same caution: it told the FDA that Galleri's marketing should continue pointing patients toward routine screening and should avoid describing the test's results as catching cancer at an early stage.

Cristian Tomasetti, who directs early detection research at City of Hope's cancer center, reads the missed endpoint differently. He says a three-year window is short for proving a drop in cancer deaths, since mortality effects from earlier detection typically take longer to appear in the data, and that a test's first few years tend to catch cancers that were already advanced before the test could have changed anything. Tomasetti helped develop an early version of the methylation-detection approach in 2018, a technology now used in a competing test from Exact Sciences, though he is no longer involved with that company.

Tom Beer, chief medical officer at Abbott Cancer Diagnostics, told the panel he sees the gap firsthand in his Oregon oncology practice. Abbott is developing its own multi-cancer test, CancerGuard, also pending FDA review. Beer said about 70 percent of cancer diagnoses and deaths come from cancers, pancreatic cancer among them, that have no recommended screening test at all, which is the population he argues a test like Galleri could reach first.

What the FDA still has to decide

More than 200 physicians, nurses, professional societies, and patient advocates submitted comments or spoke during the panel's public docket, according to Grail. Grail's chief executive, Josh Ofman, called the vote confirmation of the company's evidence in a statement issued the same day, saying it 'reaffirms a high evidence bar' the company set for itself. Michelle Tarver, who runs the FDA's device center, struck a more measured tone at the hearing, describing multi-cancer blood testing as 'a genuinely promising opportunity' that still 'demands careful, rigorous evaluation.'

The FDA is not required to follow its advisory panel's recommendation, though it usually does. Grail submitted its approval application on January 29, 2026, after the agency designated Galleri a Breakthrough Device in 2018. The agency has not said when it will issue a final decision, only that one is expected within months. Exact Sciences and Abbott are both pursuing FDA approval for competing multi-cancer tests, which makes Wednesday's vote a marker for the whole category, not just one company's product.