Cabazitaxel plus cisplatin coadministration and drug-interaction study in patients with advanced solid tumors.

e15116 Background: Cabazitaxel (Cbz) is a novel taxane with in vivo efficacy in taxane-sensitive and -resistant tumors. Therapeutic synergism of Cbz/cisplatin (Cis) has been shown in tumor-bearing mice. Since Cbz is primarily metabolized by CYP3A, drug interactions may occur with modulators of CYP3A. Methods: The primary objective of part 1 of this phase I study (NCT00925743) was to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of Cbz/Cis. Secondary objectives included safety, pharmacokinetics (PK) and efficacy. The objective of part 2 was to assess efficacy at the MTD. The effect of the antiemetic aprepitant (a moderate CYP3A inhibitor) on the PK of Cbz was also examined. Eligible patients (pts) had ECOG PS ≤ 1 and confirmed metastatic or unresectable solid tumors for which Cis therapy was considered appropriate. A 3 + 3 dose escalation at a starting dose (level 0) of 20/75 mg/m2 (Cbz/Cis), administered IV Q3W, was used. The MTD was the highest dose at which 0/3 or ≤ 1/6 ...