Phase I Study of Aurora A Kinase Inhibitor Alisertib (MLN8237) in Combination With Selective VEGFR Inhibitor Pazopanib for Therapy of Advanced Solid Tumors.

Objectives: Pazopanib is a multikinase angiogenesis inhibitor. Alisertib is a highly selective inhibitor of mitotic Aurora A kinase. There is preclinical evidence that mitosis-targeting agents exhibit antiangiogenic effects. Thus, the combination of these 2 agents may have a synergistic effect on tumor vasculature. The primary objective of this study is to determine the optimal tolerated dose (OTD) for alisertib and pazopanib. Materials and Methods: This phase 1b study evaluated the OTD of alisertib twice a day, on days 1 to 7 with pazopanib, once a day, continuously in a 21-day cycle, both taken orally. Disease response was assessed using the Response Evaluation Criteria in Solid Tumors version 1.1 every 2 cycles. OTD cohort was expanded to assure safety and perform pharmacokinetics analysis. Results: A total of 27 patients received treatment. Seventy-seven percent of the patients had received at least 3 prior chemotherapy regimens. Dose-limiting toxicities occurred in dose level (DL) 2+ (grade 4 thrombocytopenia and grade 3 mucositis) and DL 3 (grade 3 liver transaminases elevation and grade 3 abdominal pain). The OTD was determined to be DL 2: alisertib 20 mg twice daily and pazopanib 600 mg daily. Pharmacokinetic analysis revealed that clearance of alisertib was reduced by similar to 40% in the presence of pazopanib compared with clearance in the absence of pazopanib. Fourteen patients had stable disease and 2 patients had a partial response. Conclusions: The combination of alisertib with pazopanib demonstrates manageable safety and early clinical evidence of antitumor activity in patients with advanced malignancies (NCT01639911).