M. Olivera

Pembrolizumab plus chemotherapy for advanced and recurrent cervical cancer: final analysis according to bevacizumab use in the randomized KEYNOTE-826 study

In KEYNOTE-826 (NCT03635567), pembrolizumab plus chemotherapy (±bevacizumab) significantly improved overall survival (OS) and progression-free survival (PFS) in patients with persistent, recurrent, or metastatic cervical cancer. This exploratory analysis examined outcomes in patient subgroups defined by bevacizumab use. Eligible adult patients had persistent, recurrent, or metastatic squamous cell carcinoma, adenosquamous carcinoma, or adenocarcinoma of the cervix not previously treated with chemotherapy and not amenable to curative treatment; measurable disease per RECIST v1.1; and an Eastern Cooperative Oncology Group performance status ≤1. Patients were randomly allocated 1 : 1 to pembrolizumab 200 mg every 3 weeks or placebo for up to 35 cycles plus chemotherapy (±bevacizumab 15 mg/kg). Dual primary endpoints were OS and PFS per RECIST v1.1 by investigator assessment. Outcomes were assessed in subgroups defined by bevacizumab use. Hazard ratios (HRs) and 95% confidence intervals (CIs) were based on a stratified Cox regression model. A total of 617 patients were randomly assigned [pembrolizumab arm, n = 308 (63.6% with bevacizumab); placebo arm, n = 309 (62.5% with bevacizumab)]. The most common reason for bevacizumab exclusion was medical contraindication (75.9%). Among patients who received bevacizumab, HRs (95% CIs) for PFS favored the pembrolizumab arm in the programmed cell death-ligand 1 combined positive score ≥1 [0.56 (0.43-0.73)] and all-comer [0.57 (0.45-0.73)] populations; OS results were 0.60 (0.45-0.79) and 0.61 (0.47-0.80), respectively. Among patients who did not receive bevacizumab, HRs (95% CIs) for PFS also favored the pembrolizumab arm in the programmed cell death-ligand 1 combined positive score ≥1 [0.61 (0.44-0.85)] and all-comer [0.69 (0.50-0.94)] populations; OS results were 0.61 (0.44-0.85) and 0.67 (0.49-0.91), respectively. Among patients who received bevacizumab, grade ≥3 treatment-related adverse events occurred in 74.0% of patients in the pembrolizumab arm and 66.8% in the placebo arm. Pembrolizumab plus chemotherapy prolonged PFS and OS and had manageable safety compared with placebo plus chemotherapy in patient subgroups defined by bevacizumab use.

First-Line Pembrolizumab + Chemotherapy Versus Placebo + Chemotherapy for Persistent, Recurrent, or Metastatic Cervical Cancer: Final Overall Survival Results of KEYNOTE-826

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. The phase III, double-blind KEYNOTE-826 trial of pembrolizumab 200 mg or placebo once every 3 weeks for up to 35 cycles plus platinum-based chemotherapy, with or without bevacizumab, showed statistically significant survival benefits with the addition of pembrolizumab for patients with persistent, recurrent, or metastatic cervical cancer (primary data cutoff: May 3, 2021). This article reports the protocol-specified final overall survival (OS) results tested in the PD-L1 combined positive score (CPS) ≥1, all-comer, and CPS ≥10 populations. At the final data cutoff (October 3, 2022), the median study follow-up duration was 39.1 months (range, 32.1-46.5 months). In the PD-L1 CPS ≥1 (N = 548), all-comer (N = 617), and CPS ≥10 (N = 317) populations, median OS with pembrolizumab–chemotherapy versus placebo–chemotherapy was 28.6 months versus 16.5 months (hazard ratio [HR] for death, 0.60 [95% CI, 0.49 to 0.74]), 26.4 months versus 16.8 months (HR, 0.63 [95% CI, 0.52 to 0.77]), and 29.6 months versus 17.4 months (HR, 0.58 [95% CI, 0.44 to 0.78]), respectively. The incidence of grade ≥3 adverse events was 82.4% with pembrolizumab–chemotherapy and 75.4% with placebo–chemotherapy. These results show that pembrolizumab plus chemotherapy, with or without bevacizumab, continued to provide clinically meaningful improvements in OS for patients with persistent, recurrent, or metastatic cervical cancer.