Adding pembrolizumab to chemotherapy improves survival in advanced cervical cancer

Adding the immunotherapy checkpoint inhibitor pembrolizumab to chemotherapy, with or without bevacizumab, improved overall survival (OS) and progression-free survival (PFS) in people with persistent, recurrent, or metastatic cervical cancer, regardless of whether the cancer expressed PD-L1, showed research presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting.  

The findings could lead to a possible new standard of care for the first-line treatment of this patient population. 

The multinational KEYNOTE-826 phase 3 clinical trial included 617 patients with persistent, recurrent, or metastatic cervical cancer who were not already treated with systemic chemotherapy and were not eligible for curative treatment with surgery or radiation therapy. Prior treatment with radiosensitising chemotherapy was allowed.

Patients were randomly assigned to receive either pembrolizumab with chemotherapy, with or without bevacizumab (308 participants), or placebo with chemotherapy, with or without bevacizumab (309 participants), for up to 35 cycles. Of the participants, 88.8 per cent had a PD-L1 combined positive score of 1 or higher and 51.4 per cent had a PD-L1 combined positive score of 10 or higher. The dual primary endpoints of the study were OS and PFS. 

At a median follow-up of 39.1 months, OS was:  

u For patients with a PD-L1 combined positive score of 1 or higher – 28.6 months in the pembrolizumab group vs 16.5 months in the placebo group.

u For patients with a PD-L1 combined positive score of 10 or higher – 29.6 months in the pembrolizumab group vs 17.4 months in the placebo group.

u For all participants – 26.4 months in the pembrolizumab group vs 16.8 in the placebo group.

PFS was 10.4 months in the pembrolizumab group vs 8.2 months in the placebo group for all participants. 

Across the study population, pembrolizumab with chemotherapy reduced the risk of death by 37 per cent. 

“The results of this study solidify the addition of pembrolizumab to chemotherapy with or without bevacizumab in people with persistent, recurrent, or metastatic cervical cancer as the frontline standard of care for this disease. Survival significantly improved with this approach, regardless of PD-L1 expression, further supporting its use for all patients in this population,” said Dr Merry Jennifer Markham, ASCO expert.   Researchers are hoping to further understand the role of pembrolizumab in locally-advanced cervical cancer, which is being studied in a separate, ongoing phase 3 clinical trial.