Dr Duska on PFS2 Data With Pembrolizumab and Chemoradiotherapy in Cervical Cancer

“One of the interesting parts of this second analysis was the [read out of] PFS2 data. In the experimental arm, the rate [of PFS2 events] was 15.3% compared with 24.3% in the placebo arm. This was statistically significant with a hazard ratio of 0.60. The median PFS2 was not reached in either arm. These are very exciting data.”

Linda R. Duska, MD, MPH, a gynecologic oncologist and a professor in the Department of Obstetrics and Gynecology, Gynecological Oncology Division, at the University of Virginia Health as well as the associate dean for Clinical Research at UVA School of Medicine, discussed time to second progression (PFS2) data with pembrolizumab (Keytruda) in combination with chemoradiotherapy followed by pembrolizumab monotherapy for the treatment of patients with newly diagnosed, high-risk cervical cancer. She also detailed the background of the phase 3 KEYNOTE-A18 trial (NCT04221945), data from which were presented during 2025 SGO Annual Meeting on Women’s Cancer.

At a median follow-up of 29.9 months, findings from KEYNOTE-A18 demonstrated that the median PFS2 was not reached (NR; 95% CI, NR-NR) in either the investigational (n = 529) or the control arm (n = 531), Duska said, adding that the hazard ratio of 0.60 (95% CI, 0.46-0.80) was statistically significant. Patients in the pembrolizumab and placebo arm had respective PFS2 rates of 15.3% and 24.3%, she added.

KEYNOTE-A18 was a unique trial in that enrolled only patients with high-risk locally advanced cervical cancer, Duska said. To be eligible for the study, patients needed to have FIGO 2014 stage IB to IIB, node-positive disease or FIGO 2014 stage III to IVA disease irrespective of nodal status, she explained. The trial was able to accrue more than 1000 patients from 2020 to 2022, which is notable since it was conducted during the COVID-19 pandemic, she commented. All patients received cisplatin at 40 mg/m2 weekly for 5 cycles with external beam radiotherapy followed by brachytherapy, she said. Patients in the investigational arm also received pembrolizumab at 200 mg every 3 weeks for 5 cycles followed by maintenance pembrolizumab at 400 mg every 6 weeks for 15 cycles or matching placebo, she concluded.