• FDA’s reviewers did not flag major problems with the test’s accuracy or safety in the material posted ahead of the panel meeting on Wednesday. 
• Staff still asked the panel whether the evidence supports calling Galleri an “early detection” test, after a U.K. study failed to show a clear drop in late-stage diagnoses.
• Grail expects the FDA to decide on the test by the first part of 2027.

Shares of GRAIL Inc. (GRAL) soared 34% on Monday, clocking its best day since February 2025, after the U.S. Food and Drug Administration posted briefing papers that flagged no particular concerns for Wednesday’s review of the company’s Galleri blood test.

The agency’s reviewers did not flag major problems with the test’s accuracy or safety, raising investor optimism for approval of the cancer detection test after a sharp stock drop earlier this year.

The Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee will meet on Sept. 23 at the FDA’s White Oak campus in Silver Spring, Maryland, and discuss GRAIL’s premarket approval application, make recommendations, and vote. Its advice does not bind the agency.

What Galleri Does

Galleri is a prescription blood test for adults 50 and older. It looks for chemical marks on DNA fragments that tumors shed into the blood and is meant to flag many cancer types, including some that have no routine screening. If it finds a signal, it also predicts where in the body the cancer may have started. A doctor then orders follow-up tests.

The test has been sold since 2021 as a lab-developed product. GRAIL filed for full FDA approval on Jan. 29, 2026. The agency designated it a Breakthrough Device in 2018. An approval would make insurance coverage more likely.

What Reviewers Flagged

Staff said they have no leftover questions for the panel on how the test was built, how the studies were designed, or the main safety results. They cited a very low false-alarm rate and no injuries caused by the device itself but posed whether Galleri should be called an “early detection” test, or only a cancer-detection test after a UK study failed to show a clear drop in late-stage diagnoses.

The FDA panel will debate whether the test is reasonably safe, whether it works as intended, and whether benefits outweigh risks for the proposed use at the meeting. A positive takeaway from the panel would increase the chances of FDA approval. Grail expects the FDA to decide on the test by the first part of 2027.

How Did GRAL Retail Traders React?

On Stocktwits, retail sentiment around GRAL stock rose from bearish to bullish territory over the past 24 hours, while message volume increased from high to extremely high levels.

A Stocktwits user opined that investors should wait for the FDA decision and not “take wooden nickels.”

GRAL stock has gained 26% year-to-date. 

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