FDA advisory panel backs Grail’s Galleri multicancer blood test, with caveats

The useful part

Grail Inc.'s Galleri test doesn't diagnose cancer but instead, with a single blood draw, looks for a signal that someone may have one of a long list of tumors. Those who receive a positive result need additional care to tell if they're really sick. Administration's advisory panel voted 7-2, with one abstention, that the DNA-based test offers more potential benefits than risks, such as causing false assurances or raising false alarms.

How it works

• Victor van Berkel of UofL Physicians in Louisville, Kentucky, describing how more research is needed even if the test is rolled out.
• Grail also didn't provide data showing that screening with its test led to fewer cancer deaths, a metric that would have required years of follow-up.
• "They want the chance to fight their disease while the chance to survive is possible." Grail's primary study in 140,000 older adults showed that its test detected about one third of cancers diagnosed over a...
• About two-thirds of patients who received a "cancer signal detected" were later confirmed to have cancer.
• FDA reviewers at the meeting flipped the company's data to emphasize the potential downsides of that performance.

What to take from it

Risks include that the test will miss a significant number of real cancers while also flagging a potential cancer in patients who are healthy. Representatives for Grail argued that its test is a leap forward because it can pick up signs of more than 50 cancers, including dozens for which there are no screening options, such as liver and ovarian cancer. The agency's chief reviewer pointed out that the test missed 2 of 3 cancers that were diagnosed over the coming year, giving false reassurance to many patients.

Example or evidence

• "When they start having symptoms there will be tendency to delay going to the doctor — just a little bit — and that could be deadly," said Diana Zuckerman of the nonprofit National Center for Health...
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• Lots of companies are studying such blood tests and Wednesday's vote marks the first time a federal advisory group has backed the experimental approach.
• The FDA isn't bound by the advice but if it agrees, it could pave the way for widespread U.S.

Details worth keeping

"Perhaps my yes is a hopeful rather than an accurate one," said Dr. "If we can find more early-stage cancers in the population that we can't screen for currently, that will end up having benefit." The vote followed two earlier votes in which the experts affirmed that the test appears safe and effective for use by people age 50 and older. adoption of a long-sought way to find more cancers earlier.

Related coverage

• Ksn: Grail Inc.'s Galleri test doesn't diagnose cancer but instead, with a single blood draw, looks for a signal that someone may have one of a long list of tumors.
• Biopharmadive: Panel members said the first-of-a-kind blood test should not be used to replace medical guideline-recommended cancer screenings, however.