Real-world results with PARP inhibitor use for HER2-negative advanced breast cancer: prospective PRAEGNANT registry

Germline BRCA1 and BRCA2 mutations enable targeted therapies in HER2-negative advanced breast cancer (aBC). The two PARP inhibitors olaparib and talazoparib were introduced in clinical practice in 2018. Real-world analysis of data from the prospective PRAEGNANT registry in Germany investigated PARP inhibitor use for HER2-negative aBC. The analysis included 152 patients receiving a PARP inhibitor. The median real-world progression-free survival was 6.2 months (95% CI 4.8-7.9) and the median real-world overall survival was 17.1 months (14.4-22.3). Line of therapy, HR status, and treatment (olaparib versus talazoparib) affected real-world survival outcomes. Among patients with a reported germline mutation, 36.1% had a BRCA1, 62.9% had a BRCA2, and 1.0% had a PALB2 mutation. The authors conclude that outcomes were comparable to those reported in pivotal trials despite later-line use of PARP inhibitors in this analysis.