Grail's multi-cancer blood test shows no major safety concerns in FDA review

U.S. Food and Drug Administration staff reviewers raised no major concerns regarding the safety and accuracy of Grail's Galleri multi-cancer blood test, sending Grail's shares up 35% on September 21, 2026. While Galleri is already sold under clinical laboratory regulations, FDA approval would unlock insurance coverage and Medicare reimbursement. An advisory panel will meet on September 23, 2026, to discuss the test, including whether it qualifies as an early detection tool, following mixed results from a major UK trial.

FDA staff review findings

• ▪U.S. Food and Drug Administration staff reviewers raised no major concerns regarding the accuracy and safety of Grail's Galleri multi-cancer blood test in briefing documents released on September 21, 2026
• ▪The U.S. Food and Drug Administration stated in briefing documents that it has no outstanding questions for its advisory panel regarding the analytical performance, study design, and primary safety analyses of Grail's Galleri test

Galleri early detection characterization

• ▪The U.S. Food and Drug Administration requested that its external advisory panel discuss whether clinical evidence supports characterizing Grail's Galleri blood test as an early detection test
• ▪Grail has stated that its Galleri multi-cancer blood test is designed to complement, rather than replace, established cancer screening methods such as mammograms and colonoscopies

Grail UK trial results

• ▪Grail's shares declined by more than 20% after February 2026, when the company reported that routine screening with its Galleri test failed to significantly boost early detection or reduce late-stage diagnoses in a three-year United Kingdom trial
• ▪Grail submitted its premarket approval application to the U.S. Food and Drug Administration in January 2026, utilizing data from a smaller United States trial, first-year data from a pivotal three-year United Kingdom trial, and a bridging analysis

Multi-cancer blood test market

• ▪Grail's Galleri test and Abbott Laboratories' Cancerguard test are currently sold under Clinical Laboratory Improvement Amendments regulations, though neither has received U.S. Food and Drug Administration approval
• ▪Grail's Galleri multi-cancer blood test generated $136.8 million in revenue in the United States during the 2025 fiscal year

Investor reactions to briefing

• ▪Piper Sandler analyst David Westenberg characterized the U.S. Food and Drug Administration's briefing documents released ahead of the FDA's September 23, 2026 advisory committee meeting on Grail's Galleri test as constructive for Grail and stated that he expects a favorable advisory panel vote
• ▪Grail's shares rose by 35% on September 21, 2026, following the release of U.S. Food and Drug Administration staff review documents that raised no major concerns about the safety and accuracy of Grail's Galleri multi-cancer blood test ahead of the September 23, 2026 advisory panel meeting

FDA approval pathway implications

• ▪U.S. Food and Drug Administration approval of Grail's Galleri test is expected to facilitate widespread distribution, physician guideline adoption, and routine health insurance coverage, including Medicare reimbursement
• ▪An external advisory committee of the U.S. Food and Drug Administration is scheduled to meet on September 23, 2026, to review Grail's premarket approval request, though the agency is not legally bound to follow the panel's advice

Debatable claims

• ▪The FDA should approve Grail's Galleri multi-cancer blood test
• ▪Multi-cancer blood tests should be commercially available before receiving FDA approval