Grail Shares Surge 35% as FDA Staff Finds No Major Issues With Galleri Cancer Test

Grail's (GRAL) stock surged as much as 35% on Monday after U.S. Food and Drug Administration staff reviewers released briefing documents that did not raise significant concerns about the company's multi-cancer blood test, Galleri. The documents were published ahead of an external advisory panel meeting scheduled for Wednesday to discuss Grail's application for premarket approval.

Favorable Staff Review

According to the briefing documents, the FDA's staff had no outstanding questions for its advisory panel regarding Galleri's analytical performance, study design, or primary safety analyses. This suggests a positive initial assessment of the test's fundamental accuracy and safety profile.

However, the agency did ask its external advisers to discuss whether the available evidence sufficiently supports characterizing Galleri as an "early detection" test. This point will likely be a key focus of the upcoming panel discussion.

Market Impact and Outlook

The market's reaction was strongly positive, with investors seeing the staff review as a significant step toward potential FDA approval. "We view this as constructive for Grail," said Piper Sandler analyst David Westenberg in a research note, adding that he expects a favorable vote from the advisory panel.

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An FDA approval is considered critical for securing widespread adoption by physicians, inclusion in medical guidelines, and routine health insurance coverage. Galleri is currently available under the Clinical Laboratory Improvement Amendments (CLIA) regulations but lacks full FDA approval. The test generated $136.8 million in U.S. revenue in 2025, according to the company.

Background and Context

Monday's rally marks a sharp reversal for Grail's stock, which had fallen more than 20% since February. The prior decline followed news that a three-year U.K. trial failed to show that routine screening with Galleri significantly boosted early-stage cancer detection or reduced late-stage diagnoses.

Grail submitted its FDA application in January, based on data from a smaller U.S. trial and first-year data from the U.K. study. The company has stated that Galleri, which analyzes molecular signals from tumors in a blood sample, is intended to complement, not replace, existing cancer screenings like mammograms and colonoscopies.