FDA advisers back Galleri

On Sept. 23, an FDA advisory committee recommended authorization of Galleri, a blood-based test designed by Grail to identify signals associated with multiple cancers in adults 50 and older.

The committee voted 7-2, with one abstention, that Galleri’s benefits outweigh its risks. Members separately voted 10-0 on safety and 6-4 on whether there was reasonable assurance the test is effective. The recommendation is an important regulatory milestone, but it is not FDA approval. Advisory committee recommendations are nonbinding, and the agency makes the final decision on a premarket approval application.

Galleri analyzes methylation patterns in cell-free DNA found in a blood sample. When it detects a cancer-associated signal, the test is also designed to predict where that signal originated, potentially helping clinicians determine the appropriate diagnostic evaluation. It is intended to supplement, rather than replace, established cancer screening.

The regulatory review comes amid growing interest in multi-cancer detection, or MCD, tests as a possible way to expand screening beyond the handful of malignancies for which population-level screening is routinely recommended.

Large U.S. study finds more cancers with supplemental testing

One of the central pieces of evidence supporting Galleri is PATHFINDER 2, an interventional study that enrolled 35,878 adults ages 50 and older across the United States and Canada. The findings were published Sept. 22 in Nature Medicine.

Researchers reported that adding the blood test to recommended screening increased the number of cancers detected through screening approximately 6.5-fold. Among 32,007 participants included in the 12-month performance analysis, the test’s positive predictive value was 60.3%, meaning roughly six in 10 participants with a positive result who completed follow-up were ultimately found to have cancer. Its 12-month sensitivity across cancers was 39.3%.

The findings also illustrate the proposed appeal of multi-cancer testing: about 70% of cancers detected by Galleri were malignancies without existing national screening recommendations.

However, detecting additional cancers does not by itself prove that screening reduces late-stage disease or cancer mortality, a distinction that has become particularly important following results from a much larger randomized trial.

U.K. trial raises questions about clinical benefit

The NHS-Galleri trial enrolled more than 142,000 participants and compared usual care with a strategy that added Galleri testing. Unlike PATHFINDER 2, its randomized design allowed investigators to examine whether introducing the test changed cancer-stage outcomes at the population level.

The study did not meet its primary endpoint. Researchers found no statistically significant reduction in the combined incidence of stage 3 and stage 4 cancers targeted by the trial. Participants offered testing did have fewer stage 4 diagnoses, along with more early-stage cancers, but those changes did not translate into a significant improvement in the trial’s primary late-stage endpoint.

That difference between test performance and demonstrated clinical benefit is likely to remain at the center of the debate surrounding MCD screening.

Some members of the FDA advisory committee also expressed concern about calling Galleri an “early detection” test. The panel recommended that patients be clearly advised to continue established screening, such as mammography and colorectal and lung cancer screening when appropriate.

Access could change significantly with FDA approval

Galleri is already available in the U.S. by prescription as a laboratory-developed test and currently costs $949, according to publicly available information. FDA approval would represent a different regulatory status and could have significant implications for future coverage.

Federal legislation enacted in February 2026 established a pathway for Medicare coverage of FDA-cleared or approved MCD tests, subject to a national coverage determination and other requirements.

Available summaries of the legislation indicate that coverage provisions begin in 2028, with eligibility initially subject to an age ceiling that increases over subsequent years. The legislation generally permits one qualifying test every 11 months. Those restrictions can change if the U.S. Preventive Services Task Force issues an A or B recommendation for an MCD test.

Editor’s note: This differs from the supplied source, which states that Medicare coverage begins in 2029 and initially applies to beneficiaries ages 50 to 64. Legislative summaries of H.R. 842 instead describe coverage beginning in 2028 and an initial upper age threshold of 68. That detail should be checked against the enacted statutory language before publication.

What comes next

Galleri’s progress represents an important test case for the broader MCD field. These technologies offer the possibility of screening simultaneously for cancers that currently lack routine screening options, potentially changing how clinicians approach cancer detection.

At the same time, the evidence remains mixed on the question that matters most clinically: whether adding MCD testing to existing screening ultimately reduces advanced cancer and, eventually, deaths from cancer.

The PATHFINDER 2 findings demonstrate that adding Galleri can substantially increase the number of cancers identified through screening. The NHS-Galleri study, however, shows why increased detection cannot automatically be equated with improved outcomes.

That distinction will be central as the FDA evaluates Galleri’s application and as researchers continue studying the broader role of multi-cancer blood tests.