A Phase I and Pharmacokinetic Trial of Erlotinib in Combination with Weekly Docetaxel in Patients with Taxane-Naive Malignancies

Abstract

This study aimed to define the maximum tolerated dose of weekly docetaxel combined with daily erlotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor. Patients with any solid tumor received 150 mg erlotinib with escalating doses of docetaxel (20, 25, 30, and 35 mg/m(2)) on days 1, 8, and 15 every 28 days. The pharmacokinetics of docetaxel and erlotinib was determined on cycle 2, day 1. Erlotinib was given for a maximum of 12 cycles and docetaxel was given for up to 6 cycles. Twenty-five patients (17 males and 8 females) were enrolled with a median age of 56 years (range, 34-76); Eastern Cooperative Oncology Group performance status of 0/1 was 20/5. One patient had a dose-limiting toxicity in cycle 1 at the 25 mg/m(2) level (grade 3 enterocolitis). At 35 mg/m(2) docetaxel dose level, 6 of 10 patients required dose reductions to 30 mg/m(2) beyond cycle 1 due to neutropenia (3 patients) and mucositis, increased bilirubin, and diarrhea (1 patient each). The clearance of docetaxel and erlotinib of 61.7 and 8.16 L/h, respectively, did not seem to differ from historical controls. Responses were seen in non-small cell lung cancer, prostate cancer, and hepatobiliary cancers, including a complete response lasting 36+ months in a patient with hepatocellular carcinoma. Although no maximum tolerated dose was reached in cycle 1 with 35 mg/m(2) docetaxel, repetitive dosing proved intolerable in a substantial number of patients; thus, the recommended phase II dose of weekly docetaxel is 30 mg/m(2) when combined with 150 mg of daily erlotinib.