Grail's Galleri Cancer Blood Test Shows Promising Results, Eyes FDA Review

Grail, a biotechnology company focused on early cancer detection, has unveiled detailed data from its Pathfinder 2 study of the Galleri cancer blood test at the European Society for Medical Oncology (ESMO) 2025 conference in Berlin. The results demonstrate significant improvements in cancer detection rates and accuracy, paving the way for a potential FDA review.

Pathfinder 2 Study Highlights

The Pathfinder 2 study, which included over 23,000 participants aged 50 and older, showed that the Galleri test detected cancer signals in 216 individuals, with 133 subsequently receiving a cancer diagnosis. This translates to a positive predictive value of 61.6%, a substantial increase from the 43% observed in the previous Pathfinder study conducted in 2022.

Key findings from the study include:

• The test demonstrated a specificity of 99.6%, with a false positive rate of just 0.4%.
• Over half (53.5%) of the newly detected cancers were found at early stages (1 or 2).
• 69.3% of cancers were identified at stages 1 through 3, where curative treatment may still be possible.
• The overall episode sensitivity for all cancers was 40.4%.

Implications for Cancer Screening

When used in conjunction with standard cancer screening methods, the Galleri test detected approximately three times as many cancers. Dr. Josh Ofman, president at Grail, emphasized the test's potential impact, stating, "These results are extremely compelling as approximately three-quarters of the Galleri-detected cancers do not have recommended screening tests today."

The test's ability to predict the cancer's location within the body is expected to streamline diagnostic procedures, potentially leading to more efficient and targeted follow-up investigations.

Path to FDA Approval

Armed with these promising results, Grail is preparing to submit a premarket approval (PMA) application to the FDA. The company plans to include data from the Pathfinder 2 study alongside anticipated results from a large-scale trial conducted in collaboration with the UK's National Health Service (NHS).

The NHS-Galleri trial, involving over 140,000 volunteers, aims to assess the test's ability to reduce late-stage cancer diagnoses. Results from this study are expected in 2026.

Grail anticipates completing the PMA submission for Galleri, which has already received breakthrough device designation, in the first half of 2026. If the process proceeds as planned, FDA approval could potentially be granted in 2027, opening the door for insurance coverage and broader adoption of the test in clinical practice.