COLUMBUS – The combination of two novel immune therapy agents could be an effective new treatment option for women facing recurrent or advanced cervical cancer, according to the results of a multicenter phase II clinical trial led by researchers at the Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James).
The study presents the largest trial conducted to date testing the combination of a PD-1 inhibitor (balstilimab) with CTLA-4 inhibitor (zalifrelimab) in women with recurrent/metastatic cervical cancer. Researchers report an overall response rate of 26% (all study) patients, including 8% of patients who experienced complete response and a 32.8% response rate in patients whose tumors were PD-L1+ – a doubling of the expected response rates.
“Thanks to screening, most cervical cancers are detected in early or pre-cancerous stages that are very treatable. For women with an advanced or recurrent cancer, however, there are still limited medical therapies that provide durable cancer control. This data suggests the combination of balstilimab and zalifrelimab is an effective and durable new option for treating advanced or recurrent cervical cancers – particularly in patients whose tumors express PD-L1,” says Dr. David O’Malley, corresponding author and a gynecologic oncologist at the OSUCCC – James.
O’Malley notes that, while treatment benefits were most pronounced in patients whose tumors expressed a specific cellular marker known as PD-L1+ (programmed death ligand-1), significant treatment response was seen with this drug combination regardless of PD-L1 status.
The team reports its findings in the Dec. 21, 2021, online edition of the Journal of Clinical Oncology.
Cervical cancer is the most common gynecologic cancer and the fourth-leading cause of cancer death worldwide. There is currently only one approved immunotherapy treatment option approved for patients with recurrent or metastatic disease.
For this study, researchers hypothesized that two targeted drug treatments – the investigational monoclonal antibody drug balstilimab and the drug zalifrelimab – would produce an effective and durable response in patients with advanced or recurrent cervical cancer. Researchers at 45 sites across the United States, Europe, South America and Australia enrolled 155 women between the ages of 24 and 76 in the trial. All had previously been treated with at least one prior line of platinum-based chemotherapy.
Patients were treated on a six-week cycle of the balstilimab and zalifrelimab combination for up to two years, or until disease progression or side effects limited a patient’s ability to complete care.
The overall disease control rate was 52% (patients with partial, complete or stable disease) – with patients whose tumors expressed the cellular receptor PD-L1 having an overall response rate of 32.8% with an acceptable safety profile.
Researchers continue to evaluate this drug combination in a phase III clinical study. To learn more about clinical trials and gynecologic oncology treatment at the OSUCCC – James, visit cancer.osu.edu.
This study was supported by Agenus, Inc. Several study co-authors serve in advising or consulting roles for Agenus, including Dr. O’Malley. Coauthors in the study include Dr. Maryna Neffa, Bradley J. Monk, Tamar Melkadze, Marilyn Huang, Anna Kryzhanivska, Dr. Iurie Bulat, Tarek M. Meniawy, Andrea Bagameri, Dr. Edward W. Wang, Dr. Bernard Doger de Speville Uribe, Roberto Hegg, Waldo Ortuzar Feliu, Marek Ancukiewicz and Dr. Iwona Lugowska.
