Phase I Study of Veliparib (ABT-888) Combined with Cisplatin and Vinorelbine in Advanced Triple-Negative Breast Cancer and/or BRCA Mutation-Associated Breast Cancer.

Publication Type:

Journal Article

Source:

Clinical cancer research : an official journal of the American Association for Cancer Research, Volume 22, Issue 12, p.2855-2864 (2016)

Abstract:

PURPOSE: Cisplatin is synergistic with vinorelbine and the poly(ADP-ribose) polymerase (PARP) inhibitor veliparib, and has anti-neoplastic activity in TNBC and BRCA mutation-associated breast cancer. This phase I study assessed veliparib with cisplatin and vinorelbine. EXPERIMENTAL DESIGN: A 3+3 dose escalation design evaluated veliparib administered BID for 14 days with cisplatin (75 mg/m2 day 1) and vinorelbine (25 mg/m2 days 1,8) every 21 days, for six to ten cycles, followed by veliparib monotherapy. Pharmacokinetics, measurement of poly(ADP-ribose) in peripheral blood mononuclear cells, and preliminary efficacy were assessed. Immunohistochemistry and gene expression profiling were evaluated as potential predictors of response. RESULTS: Forty-five patients enrolled in nine dose cohorts plus five in an expansion cohort at the highest dose level and recommended phase II dose, 300 mg BID. Maximum tolerated dose of veliparib was not reached. Neutropenia (36%), anemia (30%), and thrombocytopenia (12%) were the most common grade 3/4 adverse events. Best overall response for 48 patients was radiologic response with 9-week confirmation for 17 (35%; 2 complete, 15 partial), and stable disease for 21 (44%). Germline BRCA mutation presence versus absence was associated with 6-month progression-free survival (10 of 14 (71%) vs 8 of 27 (30%), mid-p=0.01). Median progression-free survival for all 50 patients was 5.5 months (95% confidence interval 4.1-6.7). CONCLUSIONS: Veliparib at 300 mg BID combined with cisplatin and vinorelbine is well tolerated with encouraging response rates. A phase II randomized trial is planned to assess veliparib's contribution to cisplatin chemotherapy in metastatic TNBC and BRCA mutation-associated breast cancer.