A Randomized Phase 3 Double-Blinded Study Comparing the Efficacy and Safety of Niraparib to Placebo in Participants With Either HER2-Negative BRCA-Mutated or Triple-Negative Breast Cancer With Molecular Disease Based on Presence of Circulating Tumor DNA After Definitive Therapy (ZEST)

This study will assess the efficacy and safety of Niraparib in participants with either tumor mutation in the BRCA gene (tBRCAmut) HER2- breast cancer (Independent of hormone receptor \[HR\] status, including HR positive \[+\] and TNBC) or tumor BRCA wild type (tBRCAwt) TNBC with molecular disease based on the presence of circulating tumor Deoxyribonucleic acid (ctDNA) following surgery or completion of adjuvant therapy.