# PATHFINDER (first prospective study of the Galleri test)

Source: https://onco.cc/trials/pathfinder/  
OnCo record `pathfinder` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The first study to return Galleri results to people without symptoms and follow what happened next; its results appeared in The Lancet in 2023.

## Summary

PATHFINDER (NCT04241796) is a single-arm interventional study sponsored by GRAIL, Inc. Its primary outcomes were the number and types of diagnostic tests, and the time needed, to reach a diagnosis after a cancer-signal-detected result. The results paper (Schrag 2023) reports a signal in 92 of 6,621 analysed participants, of whom 35 had cancer.

The registry record, read on 29 October 2026, gives its status as completed, with 6,662 participants enrolled, a start on 12 December 2019 and primary completion on 1 December 2021.

## Fields

- Kind: Trial
- Status: completed
- Last checked: 2026-10-29
- Also known as: PATHFINDER; GRAIL-007; PATHFINDER 1
- Registry id: NCT04241796
- Phase: not-applicable
- Setting: Adults aged 50 and over without symptoms of cancer at US health systems, given the Galleri test alongside usual screening with results returned to their doctors
- Sponsor: GRAIL, Inc.
- Enrolled: 6662

## Sources

- ClinicalTrials.gov NCT04241796: https://clinicaltrials.gov/study/NCT04241796

## Connected records

- trials: [PATHFINDER 2](https://onco.cc/trials/pathfinder-2/)
- fronts: [Early Detection & Screening](https://onco.cc/fronts/early-detection/)
- technologies: [Liquid biopsy (ctDNA)](https://onco.cc/technologies/liquid-biopsy/), [Multi-cancer early detection (MCED)](https://onco.cc/technologies/mced/)
- drugs: [Galleri](https://onco.cc/drugs/galleri/)
- companies: [GRAIL](https://onco.cc/companies/grail/)
- key papers: [PATHFINDER: the first prospective test of a multi-cancer blood test in people without symptoms](https://onco.cc/key-papers/paper-pathfinder-lancet-2023/), [The PATHFINDER Study: Assessment of the Implementation of an Investigational Multi-Cancer Early Detection Test into Clinical Practice](https://onco.cc/key-papers/paper-pathfinder-design-cancers-2021/)

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