Galleri Blood Test: FDA Panel Backs Approval Despite Gaps in Evidence

GRAIL’s Galleri blood test, which screens for more than 50 types of cancer, received a favorable recommendation from an FDA advisory panel on September 23, 2026. The panel voted to recommend approval, signaling a potential expansion of access for American patients. However, the endorsement came with reservations regarding the test’s current efficacy and its impact on long-term survival rates.

The test identifies specific methylation markers on DNA fragments in the blood to detect potential tumors. In a study involving 32,000 U.S. adults aged 50 and older, the test correctly identified the origin of diagnosed cancer in 91% of cases. This specificity offers a distinct advantage over standard screenings, which are limited to four cancer types. Additionally, the false positive rate is approximately 0.5%, meaning one in every 200 positive results is incorrect. This is significantly lower than the 10% false positive rate seen in colorectal cancer screenings like Cologuard.

Despite these strengths, clinical data reveals limitations in early detection. Across three annual screening rounds, the test detected less than 31% of all cancer cases. The detection rate for early-stage cancers was only 21%, missing nearly 80% of such cases. Panelists noted that the test performed no better than existing standard screenings at catching disease in its most curable stages.

The panel voted 6-4 to deem the test effective, though many members conditioned their support on removing the word "early" from the product label. A separate vote of 7-2, with one abstention, determined that the test’s benefits outweigh its risks. One panel member described their affirmative vote as "hopeful" rather than fully evidence-based, acknowledging the uncertainty surrounding the test’s long-term value.

A primary concern among experts is that the trial failed to demonstrate a reduction in late-stage cancer incidence or cancer-related deaths. While there was a trend toward fewer stage four diagnoses by the third year, the data was not conclusive. The test is not a diagnostic tool; a positive result requires further invasive testing to confirm the presence of cancer.

If the FDA grants final approval, the cost of the Galleri test remains $949 out-of-pocket for many patients. Insurance coverage is not guaranteed, as the Centers for Medicare and Medicaid Services maintains a separate process for determining coverage eligibility. GRAIL did not return requests for comment regarding the panel’s recommendation.

The FDA has not yet announced when it will make a final decision on the test’s approval. The agency will review the panel’s recommendation alongside the existing data before issuing a formal ruling.