FDA Advisory Panel Weighs First Multi-Cancer Blood Test as Industry Watches Closely

A pivotal moment for early cancer detection arrived as an FDA advisory committee convened to vote on whether to recommend approval of the first multi-cancer blood test. Grail Inc.‘s Galleri blood test, which the company claims can detect up to 50 types of cancer, faces scrutiny from the agency’s Molecular and Clinical Genetics Panel during deliberations that could reshape the future of cancer screening.

The panel of independent experts heard presentations from Grail, FDA officials, and members of the public before casting their votes on a recommendation. While the FDA often follows advice from its advisory panels, the agency maintains ultimate authority over approval decisions. Ultimate approval could trigger insurance reimbursement for the test, which currently costs $949 out of pocket.

Hundreds of companies pursue the promise of blood tests to detect cancer through simple blood draws, searching for genetic material or other cancer markers shed in blood or saliva. Grail positions its Galleri test as additive to standardized cancer screenings like colonoscopies and mammograms, not as a replacement for existing protocols.

Breaking New Ground in Cancer Screening

While blood tests for cancer already exist in the market, no test screening for multiple cancers has undergone safety and accuracy reviews to win FDA approval so far. Many doctors and patients hope such technology will ultimately help detect disease earlier, when more treatment options become possible. The financial incentives to win FDA approval became far more powerful after Congress approved Medicare coverage for multi-cancer detection tests that receive agency authorization.

Based on its promise, the FDA expedited its review of Galleri, which stands furthest along in the approval process. Grail, a publicly traded company spun out of sequencing firm Illumina, currently sells the test directly to consumers through platforms such as Function Health, targeting people 50 and older.

Galleri serves as a kind of bellwether for the entire industry and for the potential use of blood tests to screen for cancers in general. Cristian Tomasetti, director of City of Hope cancer center’s early detection and monitoring division, emphasized the significance of the moment.

“It’s a new era for early cancer detection, and if the FDA approves it, it validates the overall concept,” said Tomasetti.

Critical Questions About Evidence and Accuracy

The FDA laid out key questions for the committee centered on whether the evidence behind Galleri proves strong enough to back the accuracy and timeliness claims the company would make in promotional materials. Regulators also wrestle with how to address the harms that could stem from inaccurate results, and may push Grail to include disclosures in its marketing acknowledging that the test cannot definitively confirm or exclude cancer.

The committee examined a pair of large Grail-sponsored trials-one conducted within the U.K.’s National Health Service enrolling more than 140,000 participants, and a second drawing from over 35,000 patients across North America. Both studies limited enrollment to people at least 50 years old.

The studies did not meet their primary endpoints-reducing overall mortality or the combined number of Stage III and Stage IV cancer diagnoses. However, later updates to the NHS study showed a decrease in Stage IV cancer diagnoses over the three-year period, offering a more nuanced picture of the test’s potential impact.

Interpreting Trial Results and Study Design

Tomasetti, who in 2018 was part of a team that developed a competing blood test technology now the basis of a test made by Exact Sciences (since purchased by Abbott) that also pursues FDA approval, offered perspective on the missed endpoints. He explained that the results reflect how the studies were designed rather than evidence that the technology itself falls short.

Tomasetti noted that screening trials generally need longer timeframes before mortality benefits become measurable. His assessment suggests the incomplete primary endpoints do not necessarily indicate failure in terms of the study’s substance to show evidence of the technology’s clinical value.

Industry-Wide Implications and Future Outlook

The committee’s recommendation carries implications far beyond a single company, potentially validating an entirely new approach to cancer screening. Approval would signal regulatory confidence in multi-cancer detection technology, potentially smoothing the path for competing tests from companies like Exact Sciences and Abbott that follow similar approaches.

The Medicare reimbursement structure already in place creates powerful incentives for successful navigation of the regulatory process. With Congress having authorized coverage for approved multi-cancer detection tests, companies face not only scientific validation but also access to a substantial market of eligible patients who would no longer need to pay $949 out of pocket.

The prescription-only nature of Galleri under consideration for approval represents another layer of regulatory oversight, requiring physician involvement in ordering and interpreting results. This structure aims to balance accessibility with appropriate medical guidance, particularly given the test’s limitations in definitively confirming or excluding cancer.

Balancing Promise Against Potential Risks

Regulators weigh the promise of earlier cancer detection against potential harms from false positives or false negatives. A false positive could lead to unnecessary anxiety and follow-up procedures, while a false negative might provide false reassurance and delay diagnosis. The FDA’s focus on requiring clear disclosures about the test’s limitations reflects these concerns about how patients and physicians might interpret and act on results.

The expedited review process granted to Galleri acknowledges both the urgent need for better early detection tools and the test’s advanced position in demonstrating safety and effectiveness. This accelerated timeline brings the industry closer to understanding whether regulatory pathways exist for broad adoption of multi-cancer screening technologies that could fundamentally change how medicine approaches cancer prevention and early intervention.