FDA Panel Backs Blood Test for Over 50 Cancer Types

An advisory panel for the U.S. Food and Drug Administration (FDA) has recommended the approval of the Galleri blood test, which can detect signals from over 50 types of cancer in a single blood sample. The recommendation, made by a vote of seven to two with one abstention, brings the test closer to regulatory approval in the United States, though the FDA's final decision is expected in the coming months. The panel determined that the potential benefits of the test outweigh the risks for individuals aged 50 and older. The vote on safety was unanimous, while the effectiveness vote was closer at six to four.

Developed by GRAIL, the Galleri test is part of a new generation of multi-cancer early detection (MCED) blood tests. It analyzes cell-free DNA in the blood for methylation patterns, which are chemical changes in DNA that can indicate cancerous activity. If a suspicious signal is detected, the test can also predict the tissue or organ of origin, guiding subsequent medical examinations.

Professor Eido Wolf, Director of Oncology at Ichilov Hospital, stated that the test is designed for very early cancer detection before metastasis and is intended for those over 50 due to higher cancer incidence in this age group. He emphasized that the test complements, rather than replaces, existing routine screenings like mammograms or colonoscopies. Wolf also noted that the test is not 100% guaranteed, may not detect all tumors, and a positive result requires further investigation.

Data from clinical studies, including the U.S. PATHFINDER 2 and the UK NHS-Galleri studies, supported the FDA submission. Both studies showed high specificity (over 99%), minimizing false positive results. Cancer was confirmed in about 77% of positive cases in the U.S. study and two-thirds in the UK study. However, the test identified only about one-third of cancers diagnosed within a year of follow-up. Its ability to pinpoint the tumor's origin was strong, with accuracy over 94% in the U.S. study and 92% in the UK study.

While the UK study did not meet its primary endpoint of reducing overall stage III and IV cancer incidence, it did show a significant reduction in stage IV cancer. Professor Wolf highlighted that sequential, regular use of the test shows long-term promise, with a potential 20% reduction in advanced and fatal tumors, though its impact on overall cancer mortality rates is not yet proven.

In Israel, the Galleri test is currently available privately through Oncotest for 4,200 shekels, and it is not covered by the national health insurance. Blood samples are collected locally and sent to GRAIL's labs in the United States.