FDA to review Grail's Galleri cancer test for approval after large randomized trial failed primary endpoint

FDA plans to hold a meeting of outside experts (advisory committee) in September 2026 to review Grail's multi-cancer screening test Galleri.

Galleri failed to meet the primary endpoint of a large, 142,000‑person randomized trial in the UK (NHS‑Galleri), which aimed to reduce late‑stage (Stage III–IV) cancer diagnoses by 20%.

Despite missing the primary endpoint, the trial showed a 26% reduction in Stage IV cancers among 12 prespecified cancers by the third round of screening and a four‑fold increase in cancer detection when added to standard screening.

Grail previously submitted a Premarket Approval (PMA) application to the FDA in January 2026 based on PATHFINDER 2 data and the first (prevailing) round of the NHS‑Galleri trial, plus a bridging analysis to the updated test version.

Concerns have been raised that the test has not yet demonstrated a reduction in cancer mortality or clear clinical benefit, and the failed trial complicates the regulatory and coverage outlook even though the FDA review is proceeding.

The advisory committee will focus on effectiveness and safety—particularly clinical validity—rather than directly relying on the full NHS‑Galleri utility results, which showed a missed primary endpoint but promising secondary stage‑shift signals.