Phase II Trial of Single Agent ABT-888 With Post-Progression Therapy of ABT-888 in Combination With Carboplatin in Patients With Stage IV BRCA-Associated Breast Cancer

PRIMARY OBJECTIVE: I. To evaluate the efficacy of single agent veliparib (ABT-888) (NSC 737664) in breast cancer (BRCA) carriers with metastatic breast cancer based on response rate (Response Evaluation Criteria In Solid Tumors \[RECIST\] criteria). SECONDARY OBJECTIVES: I. To conduct subset analysis on BRCA1 versus (vs.) BRCA2 and hormone receptor status. II. To evaluate progression-free survival of patients on single-agent ABT-888. III. To further describe the safety and tolerability of ABT-888 (NSC 737664) as a single agent and in combination with carboplatin for BRCA-associated breast cancer. IV. To evaluate the pharmacokinetics of ABT-888 (NSC 737664) alone and in combination with carboplatin. V. To assess the relationship between the level of poly adenosine diphosphate (ADP) ribose polymerase (PARP) inhibition by ABT-888 and biomarkers of deoxyribonucleic acid (DNA) damage in peripheral blood mononuclear cell (PBMC's) and in tumor. VI. To explore the relationship between biomarkers of drug effect and progression-free survival. VII. To evaluate the efficacy and safety of the combination of carboplatin and ABT-888 in patients who have failed single agent ABT-888. VIII. To conduct subset analysis on BRCA1 vs. BRCA2 and hormone receptor status. OUTLINE: This is a dose-escalation study of veliparib. Patients are assigned to 1 of 2 phases. SAFETY LEAD-IN PHASE: Patients receive veliparib orally (PO) twice daily (BID) on days 1-21 of each cycle and carboplatin intravenously (IV) over 30 minutes on day 1 of each cycle. Cycles repeats every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo computed tomography (CT) or magnetic resonance imaging (MRI) and may optionally undergo biopsies throughout the study. Patients undergo blood sample collection during screening and on study. PHASE II: Patients receive veliparib PO BID on days 1-21 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Upon progression, patients are taken off treatment for 1 week and may then continue to recieve veliparib along with carboplatin IV over 30 minutes on day 1 of each cycle. Cycles repeats every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo CT or MRI and may optionally undergo biopsies throughout the study. Patients undergo blood sample collection during screening and on study. \* As of the November 9, 2023 amendment, the pharmaceutical collaborator has discontinued the ABT-888 development program with the National Cancer Institute Cancer Therapy Evaluation Program (CTEP). Clinical supply will no longer be available after December 31, 2024. Patients will discontinue treatment by December 31, 2024, or earlier. After completion of study treatment, patients are followed up every 6 months.