# KEYNOTE-671

Source: https://onco.cc/trials/keynote-671/  
OnCo record `keynote-671` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Showed that immunotherapy given both before and after lung cancer surgery lengthens survival.

## Summary

KEYNOTE-671, trial NCT03425643 sponsored by Merck and reported in 2023, showed that pembrolizumab given both before and after surgery for resectable stage II to IIIB non-small-cell lung cancer lengthens survival. It randomised 797 patients to neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab, or placebo, met its primary endpoints of event-free survival and overall survival, and led to FDA approval of the perioperative regimen in October 2023, the first such regimen with a survival benefit. OnCo links it to the perioperative term and to Heather A. Wakelee and Tina Cascone, and its findings are consistent with CheckMate 816, AEGEAN, CheckMate 77T and NEOTORCH. Whether the adjuvant phase adds to neoadjuvant treatment alone has never been tested head to head, which is the trial's main unanswered question. Pembrolizumab has its own page.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-06
- Registry id: NCT03425643
- Phase: 3
- Setting: Resectable stage II-IIIB NSCLC: neoadjuvant pembrolizumab + chemotherapy then adjuvant pembrolizumab vs placebo
- Sponsor: Merck
- Enrolled: 797
- Result: EFS HR 0.58; OS HR 0.72.
- Outcomes: Event-free survival: Pembrolizumab + chemotherapy → pembrolizumab 47.2 months vs Placebo + chemotherapy → placebo 18.3 months, HR 0.59; Overall survival at 36 months: Pembrolizumab arm 71.3% vs Placebo arm 64%, HR 0.72
- Replication: Consistent with CheckMate 816, AEGEAN, CheckMate 77T, and NEOTORCH; the first perioperative regimen with an OS benefit.

## Sources

- ClinicalTrials.gov NCT03425643: https://clinicaltrials.gov/study/NCT03425643

## Connected records

- cancers: [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/), [Resectable stage I to III non-small-cell lung cancer](https://onco.cc/cancers/resectable-nsclc/)
- technologies: [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/)
- drugs: [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)
- companies: [Merck & Co. (MSD)](https://onco.cc/companies/merck/)
- terms: [Neoadjuvant / adjuvant / perioperative](https://onco.cc/terms/neoadjuvant-adjuvant/)
- people: [Heather A. Wakelee](https://onco.cc/people/heather-wakelee/), [Tina Cascone](https://onco.cc/people/tina-cascone/)
- key papers: [Five-Year Outcomes of Perioperative Pembrolizumab for Early-Stage Non-Small-Cell Lung Cancer From the Randomized KEYNOTE-671 Study](https://onco.cc/key-papers/paper-keynote-671-ann-oncol-2026-update/), [Perioperative Pembrolizumab for Early-Stage Non-Small-Cell Lung Cancer](https://onco.cc/key-papers/paper-keynote-671-n-engl-j-med-2023/)
- trials: [A Study of Neoadjuvant Chemotherapy Plus Nivolumab Versus Neoadjuvant Chemotherapy Plus Placebo, Followed by Surgical Removal and Adjuvant Treatment With Nivolumab or Placebo for Participants With Surgically Removable Early Stage Non-small Cell Lung Cancer](https://onco.cc/trials/nct04025879/), [A Study of Neoadjuvant/Adjuvant Durvalumab for the Treatment of Patients With Resectable Non-small Cell Lung Cancer](https://onco.cc/trials/nct03800134/), [Comparing the Efficacy and Safety of a New Additional Treatment With Tislelizumab in Non-Small Cell Lung Cancer (NSCLC)](https://onco.cc/trials/nct04379635/), [KEYNOTE-091 (PEARLS)](https://onco.cc/trials/keynote-091/), [Neotorch](https://onco.cc/trials/neotorch/)
- roadmaps: [Surgery roadmap: radical operations → less surgery → no surgery when a drug has done the work](https://onco.cc/roadmaps/surgery-roadmap/)

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