Grail's 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, demonstrating improved performance of its Galleri cancer blood test. The results, presented at the European Society for Medical Oncology (ESMO) 2025 in Berlin, show significant progress in the test's ability to detect multiple cancers at early stages.

Enhanced Detection Rates and Accuracy

The Pathfinder 2 study, which included over 23,000 participants aged 50 and older, revealed that the Galleri test identified a cancer signal in 216 individuals. Of these, 133 were subsequently diagnosed with cancer, resulting in a positive predictive value of 61.6%. This marks a substantial improvement from the previous Pathfinder study, which reported a 43% positive predictive value in 2022.

Key performance metrics from the study include:

• Episode sensitivity: 40.4% across all cancers
• Specificity: 99.6%, with a false positive rate of just 0.4%
• Early-stage detection: 53.5% of new cancers found at stages 1 or 2
• Overall detection: 69.3% of cancers identified at stages 1 through 3

Dr. Josh Ofman, president at Grail, emphasized the test's precision, stating, "Galleri's ability to accurately predict where in the body the cancer signal comes from also helps to guide a more efficient diagnostic workup."

Complementing Standard Screening Methods

The Pathfinder 2 study demonstrated that when used alongside recommended oncology screenings for breast, cervical, colorectal, and lung cancers, the Galleri test detected approximately three times as many cancers compared to standard screening methods alone. Notably, about three-quarters of the cancers detected by Galleri do not currently have recommended screening tests, highlighting its potential to fill critical gaps in cancer detection.

FDA Approval Process and Future Outlook

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 both the Pathfinder 2 study and an ongoing large-scale trial in the UK's National Health Service (NHS), which involves over 140,000 volunteers.

Grail anticipates completing the PMA submission for Galleri, which has received breakthrough device designation, in the first half of 2026. If approved, which could potentially occur in 2027, the test may become eligible for insurance coverage and see broader adoption in clinical practice.

While the Galleri test is already commercially available in the United States, FDA approval would mark a significant milestone in its integration into standard cancer screening protocols. As the pharmaceutical and biotechnology industries continue to advance early cancer detection methods, Grail's progress with the Galleri test represents a promising step toward improving cancer outcomes through early diagnosis and intervention.