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.