Abstract Two PARP1 inhibitors, olaparib and talazoparib, garnered regulatory approvals for the treatment of advanced HER2-negative breast cancer associated with a germline BRCA1 or BRCA2 mutation in 2018. The approvals were based on a prolongation of progression-free survival with PARP inhibitor monotherapy compared to non-DNA damaging single agent chemotherapy in the 1st - 4th line metastatic setting. While the availability of these therapies has increased therapeutic options for this group of patients, median progression-free survival ranged from 7 - 8.6 months and no overall survival advantage has been observed to date. While response rates with PARP inhibitor monotherapy are high, development of resistance remains a significant clinical problem. Further, how PARP inhibitor monotherapy compares with platinum-based chemotherapy in this group of patients has been unclear. The recently reported phase III BROCADE 3 clinical trial examining carboplatin and paclitaxel with the addition of veliparib or placebo added important insights. This was the first phase III trial in patients with advanced germline BRCA1 and BRCA2 mutation-associated HER2-negative breast cancer that examined the use of a PARP inhibitor combined with DNA damaging chemotherapy in the 1st-3rd line setting followed by blinded monotherapy after discontinuation of chemotherapy. The median progression-free survival was significantly prolonged with the addition of veliparib (14.5 versus 12.6 months) with 26% of patients in the veliparib arm remaining progression-free at 36 months. Median overall survival was 33.5 months in the veliparib arm compared to 28.2 months in placebo with 44% of patients in the placebo arm crossing over to receive veliparib after disease progression. While important differences exist between these three trials, BROCADE 3 has reported the longest progression-free and overall survival to date with PARP inhibitor therapy in advanced germline BRCA1 and BRCA2 mutation-associated breast cancer. Beyond BRCA1 and BRCA2, PARP inhibitors are also being investigated in homologous recombination deficient advanced breast cancer in a number of clinical trials. In the Talazoparib Beyond BRCA study, high clinical activity was noted in germline PALB2 mutation carriers. The Olaparib Expanded trial is ongoing. Citation Format: ML Telli. Clinical indications of PARP1 inhibitors and other targets [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr ES12-1.