Five-Year Outcomes With Pembrolizumab Versus Chemotherapy as First-Line Therapy in Patients With Non-Small-Cell Lung Cancer and Programmed Death Ligand-1 Tumor Proportion Score ≥ 1% in the KEYNOTE-042 Study.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We report 5-year results from the phase III KEYNOTE-042 study (ClinicalTrials.gov identifier: NCT02220894). Eligible patients with locally advanced/metastatic non-small-cell lung cancer (NSCLC) without EGFR/ALK alterations and with programmed death ligand-1 (PD-L1) tumor proportion score (TPS) ≥ 1% received pembrolizumab 200 mg once every 3 weeks for 35 cycles or chemotherapy (carboplatin + paclitaxel or pemetrexed) for 4-6 cycles with optional maintenance pemetrexed. Primary end points were overall survival (OS) in PD-L1 TPS ≥ 50%, ≥ 20%, and ≥ 1% groups. Patients who completed 35 cycles of pembrolizumab with ≥ stable disease could begin second-course pembrolizumab upon progression. One thousand two hundred seventy-four patients were randomly assigned (pembrolizumab, n = 637; chemotherapy, n = 637). Median follow-up time was 61.1 (range, 50.0-76.3) months. OS outcomes favored pembrolizumab (v chemotherapy) regardless of PD-L1 TPS (hazard ratio [95% CI] for TPS ≥ 50%, 0.68 [0.57 to 0.81]; TPS ≥ 20%, 0.75 [0.64 to 0.87]; TPS ≥ 1%, 0.79 [0.70 to 0.89]), with estimated 5-year OS rates with pembrolizumab of 21.9%, 19.4%, and 16.6%, respectively. No new toxicities were identified. Objective response rate was 84.3% among 102 patients who completed 35 cycles of pembrolizumab and 15.2% among 33 patients who received second-course pembrolizumab. First-line pembrolizumab monotherapy continued to show durable clinical benefit versus chemotherapy after 5 years of follow-up in PD-L1-positive, locally advanced/metastatic NSCLC without EGFR/ALK alterations and remains a standard of care.

Pembrolizumab versus chemotherapy for previously untreated, PD-L1-expressing, locally advanced or metastatic non-small-cell lung cancer (KEYNOTE-042): a randomised, open-label, controlled, phase 3 trial.

BACKGROUND: First-line pembrolizumab monotherapy improves overall and progression-free survival in patients with untreated metastatic non-small-cell lung cancer with a programmed death ligand 1 (PD-L1) tumour proportion score (TPS) of 50% or greater. We investigated overall survival after treatment with pembrolizumab monotherapy in patients with a PD-L1 TPS of 1% or greater. METHODS: This randomised, open-label, phase 3 study was done in 213 medical centres in 32 countries. Eligible patients were adults (≥18 years) with previously untreated locally advanced or metastatic non-small-cell lung cancer without a sensitising EGFR mutation or ALK translocation and with an Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1, life expectancy 3 months or longer, and a PD-L1 TPS of 1% or greater. Randomisation was computer generated, accessed via an interactive voice-response and integrated web-response system, and stratified by region of enrolment (east Asia vs rest of world), ECOG performance status score (0 vs 1), histology (squamous vs non-squamous), and PD-L1 TPS (≥50% vs 1-49%). Enrolled patients were randomly assigned 1:1 in blocks of four per stratum to receive pembrolizumab 200 mg every 3 weeks for up to 35 cycles or the investigator's choice of platinum-based chemotherapy for four to six cycles. Primary endpoints were overall survival in patients with a TPS of 50% or greater, 20% or greater, and 1% or greater (one-sided significance thresholds, p=0·0122, p=0·0120, and p=0·0124, respectively) in the intention-to-treat population, assessed sequentially if the previous findings were significant. This study is registered at ClinicalTrials.gov, number NCT02220894. FINDINGS: From Dec 19, 2014, to March 6, 2017, 1274 patients (902 men, 372 women, median age 63 years [IQR 57-69]) with a PD-L1 TPS of 1% or greater were allocated to pembrolizumab (n=637) or chemotherapy (n=637) and included in the intention-to-treat population. 599 (47%) had a TPS of 50% or greater and 818 patients (64%) had a TPS of 20% or greater. As of Feb 26, 2018, median follow-up was 12·8 months. Overall survival was significantly longer in the pembrolizumab group than in the chemotherapy group in all three TPS populations (≥50% hazard ratio 0·69, 95% CI 0·56-0·85, p=0·0003; ≥20% 0·77, 0·64-0·92, p=0·0020, and ≥1% 0·81, 0·71-0·93, p=0·0018). The median surival values by TPS population were 20·0 months (95% CI 15·4-24·9) for pembrolizumab versus 12·2 months (10·4-14·2) for chemotherapy, 17·7 months (15·3-22·1) versus 13·0 months (11·6-15·3), and 16·7 months (13·9-19·7) versus 12·1 months (11·3-13·3), respectively. Treatment-related adverse events of grade 3 or worse occurred in 113 (18%) of 636 treated patients in the pembrolizumab group and in 252 (41%) of 615 in the chemotherapy group and led to death in 13 (2%) and 14 (2%) patients, respectively. INTERPRETATION: The benefit-to-risk profile suggests that pembrolizumab monotherapy can be extended as first-line therapy to patients with locally advanced or metastatic non-small-cell lung cancer without sensitising EGFR or ALK alterations and with low PD-L1 TPS. FUNDING: Merck Sharp & Dohme.