Breast Cancer Coverage from Every Angle

Niraparib Plus Pembrolizumab in Triple-Negative Breast Cancer: TOPACIO/KEYNOTE-162 Trial

By: Sarah Campen, PharmD
Posted: Tuesday, July 2, 2019

A study conducted by Shaveta Vinayak, MD, MS, of the Fred Hutchinson Cancer Research Center and University of Washington School of Medicine, Seattle, and colleagues found that combination therapy with niraparib plus pembrolizumab appears to offer antitumor activity in patients with advanced or metastatic triple-negative breast cancer. The TOPACIO/KEYNOTE-162 trial, published in JAMA Oncology, identified no new safety signals with the combination of a PARP inhibitor and an immune checkpoint inhibitor compared with monotherapy.

“These findings suggest that PARP inhibitors plus PD-1 blockade may provide clinically relevant improvements in [duration of response],” concluded Dr. Vinayak and colleagues.

The open-label, single-arm, phase II trial enrolled 55 patients with advanced or metastatic triple-negative breast cancer, irrespective of BRCA mutation or PD-L1 status. Patients received 200 mg of oral niraparib once daily in combination with 200 mg of intravenous pembrolizumab on day 1 of each 21-day cycle. Of the 47 women in the efficacy-evaluable population, the objective response rate was 21% (10 patients), and the disease control rate was 49% (23 patients). The median duration of response has not yet been reached.

The objective response rate and disease control rate in 15 patients with tumor BRCA mutations were 47% and 80%, respectively. However, for the 27 women with BRCA wild-type tumors, the objective response rate was 11%, and the disease control rate was 33%.

As for safety, the investigators found that the combination therapy was associated with a tolerable safety profile. The most common treatment-related adverse events of grade 3 or higher were anemia (18%), thrombocytopenia (15%), and fatigue (7%); no new safety signals were detected.

“To confirm the findings of this trial, further clinical development of niraparib in combination with PD-1 inhibition in larger-scale studies is under consideration,” the investigators noted.

Disclosure: The study authors’ disclosure information may be found at

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