New York, Feb 20, 2026, 14:08 EST — Regular session
- GRAIL plunged nearly 50% after mixed UK trial results hit for its Galleri blood test, leaving investors reeling.
- The study failed to hit its primary endpoint, muddying the argument for widespread screening and reimbursement.
- Attention turns to U.S. regulators, with investors eyeing Medicare data tied to late-stage cancer reduction.
GRAIL, Inc. shares tumbled 49.8% to $51.00 during Friday afternoon trading, hitting a session low of $45.51 earlier amid heavy volume.
Sellers hit the stock after late-Thursday results from a three-year UK trial showed Grail’s Galleri blood test, used for routine screening, didn’t make a meaningful dent in early detection rates or late-stage cancer diagnoses. England’s National Health Service ran the study. The timing isn’t great for Grail, which is chasing U.S. approval and looking to shore up Galleri’s reimbursement prospects—a key factor for shifting the test away from direct-pay. TD Cowen’s analyst called for the company to “be proactive, transparent and deliberate about laying out in detail all the moving pieces.” Guggenheim’s Subbu Nambi flagged the data as a tougher sell for UK adoption compared to a U.S. review. Reuters
But Grail focused on other results from the trial. The company pointed out that adding Galleri to standard screening led to “a substantial reduction in Stage IV cancer diagnoses” along with better early detection. That’s despite the trial falling short of its main goal: showing a statistically significant drop in combined Stage III-IV cancers. Bob Ragusa, the CEO, called the dataset “the strongest evidence to date” for multi-cancer screening’s potential to shift diagnosis to earlier stages. Grail also plans to extend follow-up by six to 12 months. GRAIL
The debate hinges on the phrase “statistically significant.” Put simply, it’s about whether the gap between the test group and the control group is big enough for researchers to dismiss random chance, using a predetermined confidence threshold. If a study doesn’t clear that hurdle, policymakers usually hit the brakes.
That’s significant since Galleri targets asymptomatic individuals. When it comes to screening, regulators, insurers, and doctors generally demand evidence showing more than just cancer detection—they want to see that the difference is real, can be duplicated, and, crucially, that it actually impacts patient outcomes.
Grail posted its quarterly numbers and business update Thursday. Fourth-quarter revenue climbed 14% to $43.6 million. The company moved more than 185,000 Galleri tests in 2025, closing the year with $904.4 million in cash and marketable securities. Grail completed its FDA Premarket Approval submission for Galleri in January, but the test isn’t FDA cleared or approved, the company said.
The risk is clear enough. Should extended trials not bolster late-stage disease outcomes, or if U.S. regulators end up valuing the UK utility data more than optimists hope, shares may continue to move as a proxy for reimbursement probability.
Investors are eyeing the pace at which doctors and health systems pick up the test, and scrutinizing if the evidence supports the Medicare coverage pathway that Grail brought to the fore this week.
Looking ahead, the next big date for cancer-screening news is the 2026 ASCO Annual Meeting in Chicago, set for May 29 to June 2. That’s typically when companies unveil key clinical data.
