FDA Sets a September Panel on GRAIL’s Galleri Blood Test

FDA will convene its Molecular and Clinical Genetics Panel on 23 September 2026 to review GRAIL, Inc.'s premarket approval application for Galleri, a blood test designed to screen for dozens of cancer types at once. The meeting notice, published in the Federal Register on 8 August 2026, is procedural on its face — a date, a docket, a set of deadlines — but it marks a genuine first: no multi-cancer early detection test has ever reached an FDA advisory panel before.

What Galleri is built to do

Galleri is a prescription-only, next-generation-sequencing in vitro diagnostic. It looks for cancer-specific methylation patterns in cell-free DNA isolated from a standard blood draw, intended to screen adults aged 50 and older for multiple types of cancer — including several with no recommended screening test today — in a single test. When it returns a signal, Galleri is also designed to predict the Cancer Signal Origin, pointing toward where in the body the cancer likely arose, to guide the diagnostic work-up that follows. FDA's notice frames the meeting narrowly: the panel will discuss, make recommendations on, and vote on the evidence in GRAIL's PMA, not on the test's use outside that application.

The evidence on the table

GRAIL submitted the final module of its PMA to FDA on 29 January 2026. The filing centers on two studies. PATHFINDER 2, the US registrational trial, contributes safety and performance data from 25,490 consented participants with at least one year of follow-up. The NHS-Galleri trial — the largest randomized, controlled trial of an MCED test in an intended-use population — adds results from more than 70,000 participants in its intervention arm, drawn from the first screening round. GRAIL has said the PMA includes a bridging analysis linking the Galleri version used in both trials to the updated version submitted for approval.

The most recent performance figures GRAIL has disclosed publicly — presented at the 2026 ASCO Annual Meeting from a PATHFINDER 2 cohort of more than 35,000 participants — reported 69.8% episode sensitivity for twelve cancers responsible for roughly two-thirds of US cancer deaths, 39.3% episode sensitivity across all cancer types, 99.6% specificity, and a 60.3% positive predictive value. Those are topline trial results, not confirmed contents of the PMA itself; the panel meeting is where FDA's own analysis of the submitted data will surface.

Why the panel matters beyond one product

MCED testing has been a crowded development category for years without a single FDA-reviewed product to anchor it. This meeting changes that: whatever evidentiary questions the committee raises about specificity in an asymptomatic screening population, about false-positive follow-up burden, or about how trial-arm results translate to product labeling will become the reference points every subsequent MCED sponsor has to answer. It is the same open-panel mechanism FDA has used elsewhere to put a novel product's evidence in front of outside experts before a licensing decision — the product changes, the principle does not. The docket record, once the transcript posts, will be read closely well past GRAIL's own approval decision.

What is not yet decided

An advisory committee recommendation does not bind FDA, and the panel's questions and vote are only one input into a PMA decision that remains the agency's own. FDA has not set a public target action date for the Galleri PMA, and the notice does not indicate how the agency will weigh the panel's discussion. What is fixed is the calendar: written comments are due to the docket by 16 September, oral-presentation requests by 28 August, and the panel meets 23 September — a meeting FDA is also required, under the Federal Advisory Committee Act, to hold in a session open to the public, whether attendees appear in person or online.