The GRAIL headline missed. The cancer screening revolution didn't.

What happened

The NHS-Galleri trial: the numbers behind the noise

The NHS-Galleri trial enrolled 142,000 participants aged 50–77 across England, making it by far the largest prospective, randomised trial of any multi-cancer early detection / screening test in the world. Participants provided three blood draws over two years, about 12 months apart, and were followed for three years.

The primary endpoint was a statistically significant reduction in combined Stage III and IV cancer diagnoses. It was not met.

But the secondary and exploratory endpoints told a different story entirely:

• 4× higher overall cancer detection rate vs. standard of care (breast, colorectal, cervical, and high-risk lung cancer within NHS screening)
• >20 % reduction in Stage IV diagnoses for 12 of the deadliest cancer types in rounds 2 and 3
• Increased Stage I and II detection of cancers that are typically found too late
• Fewer emergency clinical presentations which is a proxy for late diagnosis, strongly correlated with mortality
• No serious safety concerns

GRAIL plans to extend follow-up by 6–12 months, and the trend lines suggest the effect is building over time.

Impact on our Investment Case

Early cancer detection is a long-term conviction of our Bionics strategy

Cancer is the world’s second leading cause of death, and we address it through several angles most notably earlier and better detection. In practice, that means exposure to imaging (hardware plus AI-enabled software) and to liquid biopsy. Liquid biopsy covers: MCED (multi-cancer early detection / screening), MRD (minimal residual disease—monitoring for relapse after treatment), and treatment selection (using tumor signals to help choose the right therapy). 

We have been investing in liquid biopsy since late 2019. Guardant Health, focused on colorectal cancer detection, was even the top2 position in Q1 2020. Natera Inc, a leader in post-treatment monitoring (MRD), has been in our top three holdings since Q1 2024. And lately, we initiated a position in GRAIL INC. as an MCED (screening) play in November 2025, before the MCED test legislation passed and the NHS-Galleri trial readout was released.

Why the primary endpoint was going to be hard to hit

The trial's design contained a structural challenge: the prevalent round dilution effect. In the first screening round, Galleri catches a backlog of pre-existing, already advanced cancers that have been silently growing for years. These prevalent cases artificially inflate late-stage counts in the intervention arm during year 1, diluting the stage-shift signal.

It is only in rounds 2 and 3, once the prevalent pool is cleared, that the true incident-screening benefit emerges. And that is exactly what the data showed.

Second, the endpoint bundled Stage III with Stage IV. In an era where Stage III cancers increasingly have effective treatment options, the most clinically meaningful shift is from Stage IV to Stage III and from Stage IV to Stage I–II. By combining III + IV into a single metric, the trial blunted the clearest signal.

Third, three years of screening with ~12 months follow-up is also relatively short for a population-level cancer screening trial. It took decades to demonstrate mortality benefits in mammography or colonoscopy programmes.

The FDA did not force this endpoint. The trial was designed to convince the UK's National Screening Committee to adopt Galleri as a national programme. For that, GRAIL wanted to show population-level impact, not just test performance. Late-stage (III+IV) reduction was chosen because it is the gold-standard surrogate for mortality benefit in screening trials and can be measured in years rather than decades. GRAIL set itself a harder bar than the FDA ever asked for, and the market is now punishing them for it.

We were aware of the high bar for the primary endpoint, but it also meant the payoff, if positive, outweighed the risk, and a miss would not derail the approval and commercial path.

The FDA doesn't care about clinical utility, it cares about clinical validation

This is the single most misunderstood point. GRAIL's PMA submission to the FDA, completed in January 2026, is built on test performance data from PATHFINDER 2 (35,000 U.S. participants) and the prevalent screening round of NHS-Galleri. Sensitivity, specificity, positive predictive value (PPV), and cancer signal of origin (CSO) accuracy — these are the metrics the FDA evaluates. 

On the Q4 earnings call, GRAIL's Chief Scientific Officer stated there was "not an obvious correlation or obvious impact" between the NHS-Galleri final results and the FDA's assessment. The FDA has been clear publicly: its focus is clinical validation, not clinical utility. The PMA remains on track for a ~12-month review.

The commercial story is intact and accelerating

GRAIL sold over 185,000 Galleri tests in 2025, growing U.S. revenue 26 % year-over-year to $136.8 million. The Hims & Hers partnership extends consumer access. Samsung collaboration plans are underway. The company guided to 22–32% revenue growth in 2026.

With $904 million in cash, GRAIL has a runway into 2030 that is more than enough to reach potential FDA approval and commercial scale-up.

Medicare coverage is now a matter of when, not if

New U.S. federal legislation has established a dedicated Medicare coverage pathway for MCED tests as we discussed in our previous article. This structural catalyst is entirely independent of the NHS-Galleri primary endpoint and removes the single biggest reimbursement uncertainty that has hung over the MCED category for years.

GRAIL has no peer in clinical evidence

No other MCED competitor — not Exact Science, not Freenome, not Singlera has a randomised controlled trial of this scale. The NHS-Galleri data, even with the primary miss, represents the most robust evidence base in the entire liquid biopsy space. That moat only deepens as GRAIL extends follow-up and publishes granular subgroup analyses.

If the valuation was stretched, it is now attractive

Before the readout, GRAIL's market cap stood at roughly $4 billion, about 25× trailing revenue,  making it the most expensive name in diagnostics. At that level, the stock was unambiguously pricing in a clean primary endpoint hit, NHS adoption momentum, and a de-risked FDA pathway all at once. The overnight crash to ~$50 reprices the company at roughly $2 billion. Strip out the $904 million cash pile and the enterprise value falls to just ~$1.1 billion, or about 6–7× 2026 guided revenue. For context, that is the cheapest valuation in the genetic diagnostics peer group.

In other words, the market went from pricing perfection to pricing doubt, when the reality is arguably much closer to the bull case. The revenue trajectory is intact (26% U.S. growth, 185k+ tests sold), the Pre-Market Approval is submitted, Medicare coverage is legislated, and the clinical data, while missing a rigid statistical threshold, delivered exactly the kind of real-world signals (4× detection, Stage IV reduction) that drive physician adoption and payer engagement.

Our Takeaway

Cancer kills 10 million people a year. Most of them are diagnosed too late. GRAIL just showed, in the world's largest screening trial, that a simple blood test can change that. The primary endpoint can wait. The patients cannot.

The market sold the headline. At atonra, we buy the data underneath it. A blood test that finds cancers 4× more often, reduces the most lethal stage diagnoses by >20 %, and catches tumours at stages where cure rates are dramatically higher is not a failed trial.