The addition of pembrolizumab to chemotherapy and bevacizumab prolongs progression-free survival (PFS) and overall survival (OS) among patients with cervical cancer across several key subgroups, according to an analysis of the phase 3 KEYNOTE-826 trial.

These findings were presented by Krishnansu Sujata Tewari, MD, University of California, Irvine, Orange, lead author of the study, at the 2022 ASCO Annual Meeting.

The KEYNOTE-826 trial enrolled adult patients with persistent, recurrent, or metastatic cervical cancer not previously treated with chemotherapy and not amenable to curative treatment.

Patients were randomized to treatment with chemotherapy (paclitaxel plus either cisplatin or carboplatin) and either pembrolizumab (n = 308), or placebo (n = 309). Some patients received bevacizumab in addition to the other 2 therapies (n = 389 with bevacizumab, n = 228 without). The primary end points of the trial were PFS and OS.

This analysis explored pembrolizumab plus chemotherapy and bevacizumab across subgroups defined by bevacizumab use (yes or no), histology (squamous or non–squamous) platinum use (carboplatin or cisplatin), and prior chemoradiation therapy.

The median follow-up was 22 months at the data cut-off of May 3, 2021. In all subgroups of the population, the use of pembrolizumab with chemotherapy and bevacizumab prolonged PFS and OS when compared to placebo.

In the subgroup of patients who received bevacizumab the median PFS was 15.2 months with pembrolizumab vs 10.2 months with placebo (hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.47 to 0.79) and median OS was not reach vs 24.7 months, respectively (HR, 0.63; 95% CI, 0.47 to 0.87). In those who did not receive bevacizumab, median PFS was 6.3 months with pembrolizumab vs 6.2 months with placebo (HR, 0.74; 95% CI, 0.54-1.01) and median OS was 16.8 months vs 12.6 months, respectively (HR, 0.74; 95% CI, 0.53 to 1.04).

In the subgroup of patients with squamous histology, median PFS was 10.4 months with pembrolizumab vs 6.9 months with placebo (HR, 0.63; 95% CI, 0.50 to 0.80) and median OS was 23.5 months vs 14.2 months, respectively (HR, 0.61; 95% CI, 0.47 to 0.80). In patients with non–squamous histology, median PFS was 11.6 months with pembrolizumab vs 8.4 months with placebo (HR, 0.66; 95% CI, 0.43 to 1.00) and median OS was not reached vs 21.3 months, respectively (HR, 0.76; 95% CI, 0.47 to 1.23).

In the subgroup of patients who received carboplatin, median PFS was 10.2 months vs 7.4 months with placebo (HR, 0.69; 95% CI, 0.55 to 0.86) and median OS was 21.4 months vs 15.9 months (HR, 0.59; 95% CI, 0.32 to 1.09). In patients who received cisplatin, the median PFS with pembrolizumab was 15.2 months vs 8.4 months (HR, 0.47; 95% CI, 0.28 to 0.77) and median OS was not reached vs 21.3 months, respectively (HR, 0.59; 95% CI, 0.32 to 1.09).

Among patients who received prior chemoradiation therapy, the median PFS was 10.3 months with pembrolizumab vs 6.3 months with placebo (HR, 0.62; 95% CI, 0.45 to 0.86) and median OS was 21.3 months vs 12.6 months, respectively (HR, 0.64; 95% CI, 0.45 to 0.91).

Source:

Tewari KS, Colombo N, Monk BJ, et al. Pembrolizumab + chemotherapy in patients with persistent, recurrent, or metastatic cervical cancer: Subgroup analysis of KEYNOTE-826. Presented at: ASCO Annual Meeting; June 3-7, 2022. Chicago, IL, and virtual. Abstract 5506.