PATHFINDER 2
PATHFINDER 2 is the US real-world study of the Galleri test that forms the core of its FDA submission.
25,490 participants with one-year follow-up in the PMA. Reported PPV ~60% and cancer signal detection rate ~1%; seven-fold more cancers detected when added to standard screening per GRAIL's ESMO 2025 presentation.
- 0.9 out of 100 people reached this endpoint with Galleri, all participants.
- 61.6 out of 100 people reached this endpoint with Galleri.
- 99.6 out of 100 people reached this endpoint with Galleri.
- There was no comparison group, so this number cannot tell you how much of the effect is due to the treatment.
- This endpoint is not one of the standard survival or response measures; read it alongside the trial's primary result.
- These results apply to the people the trial enrolled: ~35,000 adults ≥50 receiving Galleri alongside standard screening, single-arm. People in a different situation may not see the same effect.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
35,878 participants enrolled.
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Cancer signal detected | Galleri, all participants | 25,578 | 0.93% | — | — | link |
| Positive predictive value | Galleri | — | 61.6% | — | — | link |
| Specificity | Galleri | — | 99.6% | — | — | link |
A multi-cancer blood test can be run in ordinary clinics, and most positive results can be resolved with imaging. But six in ten positives are false alarms that take months to resolve, and the test misses most cancers. Whether it reduces late-stage cancer or deaths is unknown; that requires randomised trials.
NHS-Galleri is the trial that will decide whether a blood test for many cancers at once should be offered by a health system. Its endpoint is a reduction in late-stage cancer rather than deaths, so even a positive result leaves the mortality question to be settled by longer follow-up.
Pages like this
not linked directly; found by shared links- TrialNHS-Galleri
Shares Pre-agreed update rules so an MCED test is not obsolete when its trial reads out, Let MCED trials read out on late-stage incidence, with mortality follow-up mandated, A whole-population cancer interception programme: risk-stratify every adult, detect and intercept early, NHS-Galleri: design of the largest randomised trial of a multi-cancer blood test.
- IdeaMulti-cancer blood test as the first step for patients with non-specific symptoms
Shares Galleri, Positive predictive value (PPV), Multi-cancer early detection (MCED), Most lethal cancers are found late.
- IdeaBlood-based pancreatic cancer detection in new-onset diabetes
Shares Galleri, Positive predictive value (PPV), Multi-cancer early detection (MCED), Most lethal cancers are found late.
- IdeaA 28-day national pathway for people with a positive multi-cancer blood test
Shares PATHFINDER: the first prospective test of a multi-cancer blood test in people without symptoms, Positive predictive value (PPV), Multi-cancer early detection (MCED), Most lethal cancers are found late.
- IdeaFAPI PET as the workup for MCED positives
Shares A whole-population cancer interception programme: risk-stratify every adult, detect and intercept early, Galleri, Multi-cancer early detection (MCED), Most lethal cancers are found late.
- CompanyGRAIL
Shares Pre-agreed update rules so an MCED test is not obsolete when its trial reads out, Galleri, Multi-cancer early detection (MCED), Most lethal cancers are found late.
- CompanyHarbinger Health
Shares Positive predictive value (PPV), Multi-cancer early detection (MCED), Most lethal cancers are found late.
- IdeaRegistry-based randomised MCED trial: a million people, no study visits
Shares NHS-Galleri: design of the largest randomised trial of a multi-cancer blood test, Multi-cancer early detection (MCED), Most lethal cancers are found late.