Does Adding Pembrolizumab to Chemoradiotherapy Improve Survival in Patients with Locally Advanced Cervical Cancer?

Using pembrolizumab with platinum-based chemotherapy has been shown to be effective in patients with PD-L1–positive, persistent, recurrent, or metastatic cervical cancer. Now, in a manufacturer-supported, randomized, double-blind, international, phase 3 trial, researchers evaluated survival outcomes with pembrolizumab in 1060 adult patients with locally advanced cervical cancer who were receiving chemoradiation.

Eligible patients had newly diagnosed, high-risk squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma of the cervix (FIGO 2014 stage IB2–IIB with node-positive disease or stage III–IVA). The study arms were either pembrolizumab plus chemoradiotherapy followed by maintenance pembrolizumab, or placebo plus chemoradiotherapy followed by maintenance placebo. Over 94% of study participants had positive PD-L1 expression (combined positive score, ≥1).

The median follow-up was almost 18 months in both arms. Rates of progression-free survival at 24 months were 68% in the pembrolizumab arm and 57% in the placebo arm, with a hazard ratio for disease progression or death of 0.70, a significant finding. Estimated overall survival at 24 months was 87% in the pembrolizumab arm and 81% in the placebo arm. A higher percentage of patients in the pembrolizumab arm than in the placebo arm experienced grade 3 or higher adverse events (75% and 69%, respectively), but no new safety signals were identified.