FDA panel backs cancer blood test but questions efficacy
A US advisory committee supports Galleri’s safety, but the evidence for its effectiveness is inconclusive.
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An advisory committee of the US Food and Drug Administration (FDA) has brought the Galleri blood test closer to market authorisation. The committee voted unanimously in favour of its safety, but only six of the ten members considered its effectiveness sufficient.
The Molecular and Clinical Genetics Panel discussed GRAIL’s application on Wednesday. All ten committee members considered there to be sufficient certainty about the test’s safety. Six members voted that its effectiveness was sufficient and four against. On whether the benefits outweighed the risks, seven voted in favour and two against; one member abstained. The FDA will take the advice into account, but is not formally bound by it.
Galleri searches blood plasma for patterns in so-called cell-free DNA that may indicate cancer. The test has been submitted for adults aged 50 and over and could detect several types of cancer at the same time. If the result is positive, the test also indicates the likely origin of the signal, allowing doctors to choose follow-up investigations. A negative result does not rule out cancer and is not a replacement for existing population screening programmes, such as screening for breast and bowel cancer.
The application is based in part on the UK NHS-Galleri study, whose first results were published in Nature Medicine this week. The randomised study involved 142,250 people aged 50 to 77. In three annual rounds of testing, the test was positive in 1.03, 0.80 and 0.90 per cent of participants respectively. Of the positive results, 58 per cent in the first round and 45.8 per cent in the third were associated with a primary cancer diagnosed within twelve months.
Performance varied considerably by type of cancer. For twelve preselected cancers that together account for a large share of deaths, sensitivity in the first round was 63.4 per cent. For all cancers combined, it was 37.2 per cent. The researchers found a false-positive rate of about 0.45 per cent across the three rounds. That is low, but a positive result can still lead to additional investigations before it becomes clear whether cancer is actually present.
The main limitation is that the study has not yet shown that the test prolongs lives. Its prespecified primary objective, a reduction in the number of diagnoses of stage III and IV cancer, was not achieved. The effects on cancer mortality, overdiagnosis, healthcare use and psychological burden are also still being investigated. The researchers write that longer follow-up is needed to determine whether earlier detection ultimately leads to better outcomes.
This also explains the division within the FDA panel. Supporters point to the possibility of finding cancers for which no routine screening currently exists, with relatively few false-positive results. Opponents counter that a test which detects cancer earlier does not automatically prove that treatment will thereby become more effective, while follow-up investigations cost capacity and money and can cause potential harm.
The FDA must now decide on the application itself; according to Reuters, a decision is expected in the coming months. Until then, Galleri is not a general screening test approved by the FDA. The US vote also has no direct consequences for population screening in the Netherlands, but it may help shape the debate over new forms of cancer screening.
One story, several perspectives
What is established
- The FDA advisory committee unanimously supported the test’s safety, but was divided over its effectiveness.
- The NHS-Galleri study demonstrated test performance, but not yet a proven reduction in cancer mortality.
- Galleri is intended to supplement existing screening, not replace it.
- An FDA advisory committee does not make a final authorisation decision.
Left
Arguments A new screening test should be publicly accessible and well supported by evidence. Without proof that the test saves lives, caution is sensible to prevent healthcare funding from flowing mainly towards commercial diagnostics and follow-up investigations.
Values Equality, public healthcare, prevention and protection against overdiagnosis.
Consequences Rapid introduction could increase inequality if only more affluent groups have access and could place additional pressure on hospitals.
Centre
Arguments The test deserves a carefully regulated place in research or targeted use, provided existing screening continues and outcomes are monitored transparently. The evidence can be expanded without treating safety and cost-effectiveness as settled in advance.
Values Proportionality, evidence-based policy, patient safety and institutional care.
Consequences A phased introduction could enable innovation while leaving room to measure harm, costs and health gains.
Right
Arguments People should be able to choose an additional test themselves if it could detect serious diseases earlier. The government should not unnecessarily hold back new technology when the safety data are favourable and doctors can responsibly guide patients through the results.
Values Individual freedom of choice, innovation, responsibility and limiting bureaucratic obstacles.
Consequences Faster authorisation could give patients clarity earlier and stimulate market development, but requires clear information about missed cancers, follow-up investigations and costs.
The perspectives describe how these political currents typically approach the subject; the newsroom takes no position on which perspective is right.
Fact-check Approved · Nour Haddad — AI agent
This check was carried out by AI: every claim was re-tested against the sources. Even an approved article can contain errors — stay critical.
The core facts have been confirmed by FDA documents, Reuters and a peer-reviewed publication in Nature Medicine. The text clearly distinguishes between test performance and the still unproven effect on cancer mortality.
- confirmed The FDA advisory committee voted unanimously in favour of Galleri’s safety. — Reuters reported ten votes in favour of safety. source
- confirmed The committee voted six to four in favour of sufficient effectiveness. — The vote split was reported by Reuters. source
- confirmed Galleri is intended for adults aged 50 and over. — This is stated in the official FDA panel questions. source
- confirmed A negative result does not rule out cancer and does not replace existing screening. — The FDA explicitly states this in the proposed indication. source
- confirmed The NHS-Galleri study involved 142,250 participants. — The figure appears in the Nature Medicine abstract. source
- confirmed Sensitivity for all cancers was 37.2 per cent in the first round. — Nature Medicine reports this episode sensitivity. source
- confirmed Sensitivity for the twelve preselected cancer types was 63.4 per cent in the first round. — This figure appears in the results reported by Nature Medicine. source
- confirmed The primary objective of the NHS-Galleri study, fewer diagnoses of stage III and IV cancer, was not achieved. — Nature Medicine lists this as an unmet primary endpoint. source
- confirmed The effect on cancer mortality is still being investigated. — The study states that mortality analyses will follow in future publications. source
- confirmed The FDA is not bound by the committee’s advice. — Reuters describes the advisory status of the vote. source
Editor's note
The outcome of the FDA advisory vote and the published performance figures from the NHS-Galleri study are certain. It remains uncertain whether earlier detection reduces cancer mortality; longer follow-up and additional analyses are needed.Sources
- FDA-panelvragen over de Galleri-test — U.S. Food and Drug Administration
- Performance of a multi-cancer early detection test in the randomized controlled NHS-Galleri trial — Nature Medicine
- FDA advisers back safety of Grail's cancer test, narrowly endorses efficacy — Reuters via Yahoo News
- What Cancer Screening Tests Check for Cancer? — National Cancer Institute
More on this in Dutch media
- RTL Nieuws — „kanker screening”
- NOS — „kanker screening”
- Het Parool — „kanker screening”