Research Publications


Iniparib administered weekly or twice-weekly in combination with gemcitabine/carboplatin in patients with metastatic triple-negative breast cancer: a phase II randomized open-label study with pharmacokinetics

Dieras, V; Bonnefoi, H; Alba, E; Awada, A; Coudert, B; Pivot, X; Gligorov, J; Jager, A; Zambelli, S; Lindeman, GJ; Charpentier, E; Emmons, GT; Garcia-Ribas, I; Paridaens, R; Verweij, J
Breast Cancer Research and Treatment
Journal Article
PURPOSE: Metastatic triple-negative breast cancer (TNBC) is a phenotypic breast cancer subgroup with a very poor prognosis, despite standard treatments. Combined twice-weekly iniparib and gemcitabine/carboplatin (GC+tw-iniparib) showed benefit over gemcitabine/carboplatin in a randomized phase II trial, and a phase III was initiated comparing these regimens. The present phase II study was initiated to compare GC+tw-iniparib with a more practical once-weekly schedule (GC+w-iniparib) in TNBC. METHODS: Metastatic TNBC patients were randomized to receive iniparib weekly (11.2 mg/kg on days 1 and 8) or twice-weekly (5.6 mg/kg on days 1, 4, 8, and 11) with gemcitabine (1000 mg/m(2)) and carboplatin (area under the curve 2 on days 1 and 8), every 3 weeks. The primary endpoint was the overall response rate (ORR). Pharmacokinetics of iniparib and its two metabolites were analyzed. RESULTS: A total of 163 patients were randomized, 82 GC+w-iniparib and 81 GC+tw-iniparib. Demographic and baseline characteristics were well balanced. ORR was 34.1% (95% CI 23.9-44.4%) vs. 29.6% (95% CI 19.7-39.6%) and median progression-free survival was 5.5 months (95% CI 4.2-5.7) vs. 4.3 months (95% CI 3.0-5.8) for GC+w-iniparib and GC+tw-iniparib, respectively. Safety was similar across treatment arms in terms of event severity and type. Iniparib plasma concentrations and exposure were two-fold higher with w-iniparib compared to tw-iniparib. Iniparib and its metabolites were cleared rapidly with a terminal half-life of < 1 h, without accumulation. CONCLUSIONS: Despite a doubled maximum concentration with weekly iniparib, no detectable differences in safety or efficacy were observed between the weekly and twice-weekly administration schedules in this population. TRIAL REGISTRATION: Identifier NCT01045304.
Cancer Biology and Stem Cells
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Creation Date 2019-06-20 10:18:08 Last Modified 2019-08-08 02:45:08