Phase I safety, pharmacokinetic and pharmacodynamic trial of BMS-599626 (AC480), an oral pan-HER receptor tyrosine kinase inhibitor, in patients with advanced solid tumors.

PURPOSE We studied the safety, tolerability, and recommended dose of BMS-599626, an orally bioavailable inhibitor of the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases. PATIENTS AND METHODS Patients with advanced solid tumors that expressed epidermal growth factor receptor (EGFR) and/or HER-2 were recruited and enrolled in a phase I, open-label, dose escalation trial of oral BMS-599626 starting at 100 mg/day given once daily for at least 28 days. RESULTS Forty-five patients received BMS-599626 (100-660 mg/day). Dose-limiting toxic effects were reported at 660 mg/day (grade 3 elevation of hepatic transaminases [two patients] and QTc interval prolongation [one patient]), therefore the recommended maximum tolerated dose was 600 mg/day. The most frequent drug-related toxic effects were diarrhea (30% of patients), anorexia (13%), asthenia (30%), and cutaneous toxic effects, including skin rash (30%). Pharmacokinetic analysis demonstrated C(max) and exposure to BMS-599626 in patients increased with dose. Eleven patients had stable disease and received BMS-599626 for ≥ 4 months. Serial skin and tumor biopsies taken before and after treatment revealed expected changes in pharmacodynamic biomarkers, indicating that the EGFR and HER-2 pathways were affected. Positron emission tomography imaging showed a metabolic response in 2 of 10 patients evaluated. CONCLUSION BMS-599626 was generally well tolerated, with disease stabilization across a range of tumor types and doses.