Clinical trialPhase 3Lung cancer

Five-Year Outcomes of Perioperative Pembrolizumab for Early-Stage Non-Small-Cell Lung Cancer From the Randomized KEYNOTE-671 Study

Ann Oncol · 2026797 patients (397 pembrolizumab, 400 placebo)

Wakelee H, Spicer JD, Gao S, Liberman M, Tsuboi M, Kato T, et al. Ann Oncol. 2026

Study type: Clinical trial
Study name: KEYNOTE-671
Phase: Phase 3
Design: Randomised (1:1), placebo-controlled trial; 5-year follow-up report
Sample size: 797 patients (397 pembrolizumab, 400 placebo)
Source: Ann Oncol · 2026
Trial registration: NCT03425643

In plain words

In this study, patients with lung cancer that could be operated on received 4 cycles of chemotherapy before surgery together with pembrolizumab or a placebo, and pembrolizumab or placebo also continued after surgery. After 5 years, about half of the patients in the pembrolizumab group had no return or growth of the cancer (compared with about a quarter in the other group), and 64.6% versus 53.6% were alive.

Key results

64.6% vs 53.6%

5-year overall survival

HR 0.74; 95% CI 0.59–0.92

49.9% vs 26.5%

5-year event-free survival

HR 0.58; 95% CI 0.48–0.69

60.4 months

Median time from randomisation to data cut-off

Range 42.6–85.8 months; data cut-off 3 July 2025

Drugs in this study:Cisplatin (Platinol)Gemcitabine (Gemzar)Pembrolizumab (Keytruda)

Dose and schedule cards

Perioperative pembrolizumab (KEYNOTE-671)

Resectable NSCLC, stage II, IIIA or IIIB (N2) (AJCC 8th edition; tumour ≥4 cm or node-positive), regardless of PD-L1Cycle length: Every 21 daysOn the page “Lung cancer” · Resectable NSCLC: treatment before or after surgery

Resectable NSCLC, stage II, IIIA or IIIB (N2) (AJCC 8th edition; tumour ≥4 cm or node-positive), regardless of PD-L1

Drug	Dose	Route	Schedule
Neoadjuvant: up to 4 cycles of 21 days
Pembrolizumab	200 mg	IV (30 min)	Day 1, before chemotherapy
Cisplatin	75 mg/m²	IV	Day 1
Pemetrexed (non-squamous) or gemcitabine (squamous)	500 mg/m² or 1000 mg/m²	IV	Pemetrexed day 1; gemcitabine days 1 and 8
Adjuvant, after surgery
Pembrolizumab	200 mg every 3 weeks (or 400 mg every 6 weeks)	IV	Start 4 to 12 weeks after surgery

Cycle length: Every 21 days
Duration: 12 weeks before surgery, then 39 weeks (up to 13 cycles) after surgery

Dose source: FDA label for pembrolizumab (description of the KEYNOTE-671 trial) and the trial publication; surgery no later than 20 weeks after the first dose; pembrolizumab dose reduction is not permitted (only interruption or discontinuation); 5-year results.

On the page “Lung cancer” · Resectable NSCLC: treatment before or after surgery

Resectable NSCLC, before and after surgery (KEYNOTE-671)

Resectable stage II, IIIA or IIIB (N2)Cycle length: Every 21 daysOn the page “Pembrolizumab (Keytruda)” · Early stages: before and after surgery or with chemoradiotherapy (FDA label)

Resectable stage II, IIIA or IIIB (N2)

Drug	Dose	Route	Schedule
Before surgery, 4 cycles
Pembrolizumab	200 mg	IV infusion over 30 minutes	Day 1
Cisplatin + pemetrexed or gemcitabine	75 mg/m² + 500 mg/m² (day 1) or 1000 mg/m² (days 1 and 8)	IV	Every 21 days
After surgery
Pembrolizumab	200 mg every 3 weeks or 400 mg every 6 weeks	IV infusion over 30 minutes	Day 1

Cycle length: Every 21 days
Duration: 12 weeks before surgery, then 39 weeks as a single agent after surgery (up to 13 cycles in the trial)

On the page “Pembrolizumab (Keytruda)” · Early stages: before and after surgery or with chemoradiotherapy (FDA label)

Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.

Treatment arms and regimens

1Perioperative pembrolizumab

Neoadjuvant (4 cycles of 21 days): pembrolizumab 200 mg IV day 1 + cisplatin 75 mg/m² IV day 1 + one of: gemcitabine 1000 mg/m² IV days 1 and 8 (squamous histology) or pemetrexed 500 mg/m² IV day 1 (non-squamous).

Surgery (lobectomy, bilobectomy, pneumonectomy or sleeve resection) no later than 20 weeks after the first neoadjuvant dose.

Adjuvant: starting 4 to 12 weeks after surgery; pembrolizumab 200 mg IV every 3 weeks for up to 13 cycles. Pembrolizumab dose reductions were not allowed (only interruption or discontinuation).

2Placebo

The same neoadjuvant chemotherapy (cisplatin 75 mg/m² day 1 + gemcitabine 1000 mg/m² days 1 and 8 or pemetrexed 500 mg/m² day 1, every 21 days, 4 cycles) with placebo (normal saline IV day 1), then surgery and adjuvant placebo every 3 weeks for up to 13 cycles.

Source of the regimen details: Dose and schedule from the full text of the Lancet 2024 report of the same trial (PMC11512588, Procedures section) and ClinicalTrials.gov NCT03425643; consistent with the Ann Oncol 2026 abstract

Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.

Study population

Adults (≥18 years) with pathologically confirmed, previously untreated stage II, IIIA or IIIB (N2) NSCLC per the AJCC 8th edition, judged resectable after surgical consultation; ECOG 0 or 1 (within 10 days before randomisation) and a tumour sample for PD-L1 testing. Stratified by stage, PD-L1 (TPS ≥50% versus <50%), histology and geographic region. Patients with EGFR mutations or ALK rearrangements were also included in the population.

Endpoints

Dual primary endpoints: event-free survival (per RECIST version 1.1, investigator-assessed) and overall survival.

Safety and side effects

In the 5-year report, safety was consistent with the known profile of each treatment, and no decline in health-related quality of life was seen in the pembrolizumab group. In the Lancet 2024 analysis (same trial): treatment-related grade ≥3 adverse events in 45% versus 38%; discontinuation of all treatment due to a treatment-related adverse event 14% versus 5%; immune-mediated adverse events and infusion reactions 26% versus 9% (grade ≥3: 7% versus 2%); treatment-related deaths 1% in each group.

Clinical significance and place in guidelines

This 5-year report shows the durability of the benefit of perioperative pembrolizumab and supports its place as one of the standard treatments for resectable non-small-cell lung cancer (stage II to IIIB with N2).

Limitations

The separate contribution of the adjuvant pembrolizumab phase cannot be isolated in this design.

Original article (DOI)PubMed ClinicalTrials.gov

This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.