Phase I study of ombrabulin in combination with paclitaxel and carboplatin in Japanese patients with advanced solid tumors

ObjectivesTo evaluate the maximum tolerated dose/maximum administered dose, safety, pharmacokinetic, and efficacy profiles of ombrabulin combined with paclitaxel and carboplatin in Japanese patients with solid tumors.MethodsOmbrabulin (25, 30, or 35 mg/m2) combined with paclitaxel (175 or 200 mg/m2) and carboplatin (AUC5 or AUC6) was administered by intravenous infusion once every 3 weeks to patients with advanced solid tumors, including cervical, ovarian, and uterine cancers. The maximum tolerated dose/maximum administered dose was defined based on the dose-limiting toxicity at cycle 1. Efficacy was assessed based on Response Evaluation Criteria In Solid Tumors (RECIST).ResultsIn total, 18 patients were recruited for this dose escalation study. One out of six patients treated with the highest doses of combination of ombrabulin (35 mg/m2), paclitaxel (200 mg/m2), and carboplatin (AUC6) presented a dose-limiting toxicity consisting of grade 3 Escherichia urinary tract infection. This dose was defined as the maximum tolerated dose of ombrabulin. The most frequent treatment-emergent adverse events were alopecia (83.3%), neutropenia and fatigue (72.2% each), decreased appetite, nausea, diarrhea, arthralgia, and myalgia (66.7% each). The grade 3-4 treatment-emergent adverse events included neutropenia (61.1%), Escherichia urinary tract infection, drug hypersensitivity, syncope, pulmonary embolism, and hydronephrosis (one patient each). In efficacy evaluation, seven patients achieved partial response or better (38.9%), including one complete response, and seven of 18 patients had stable disease (38.9%). Pharmacokinetic profiles in this Japanese study were comparable with those observed in the previous study without Japanese patients.ConclusionsAlthough the maximum tolerated dose/maximum administered dose of ombrabulin (35 mg/m2) with taxane-platinum combination may be tolerable in Japanese patients in the first cycle, the dosages in the repeated treatment should be carefully selected for further study.Trial registration numberNCT01293630.