Experts warn FDA against approving Grail’s ineffective multicancer blood test

Physician and cancer‑screening researcher H. Gilbert Welch argues that the FDA should not greenlight Grail’s multicancer blood test, noting the company’s trial of 140,000 participants used a weak surrogate endpoint and failed to meet it.

Despite the trial’s shortcomings, an FDA advisory panel has recommended approval, and new legislation would allow Medicare to cover the test, potentially shifting costs to taxpayers.

Welch points out that Grail has made bold claims about saving tens of thousands of lives, yet the company has faced lawsuits from its own investors in 2024 and 2026, raising doubts about its credibility.

He also highlights concerns about Grail’s ties to the UK’s NHS and former Prime Minister David Cameron, suggesting the test’s promotion may be driven more by political and financial interests than solid scientific evidence.