3084 Background: Cetuximab is a chimeric monoclonal antibody that selectively binds to the Epidermal Growth Factor Receptor (EGFR). This study examined single dose PK of cetuximab across a 10-fold dose range (50–500mg/m2). Methods: Thirty-nine patients with refractory solid tumors of epithelial origin were randomized to a single IV infusion of cetuximab of 50, 100, 250, 400 or 500 mg/m2. Blood samples for PK analysis were collected for up to three weeks following the first cetuximab dose. After 22 days, all patients were then administered weekly dosing of cetuximab at 250 mg/m2. Results: Results from noncompartmental PK analysis are summarized in the Table. Cetuximab serum concentrations reached a maximum at approximately 3h after initiation of infusion and then declined slowly thereafter. Concentrations approached baseline levels within 504 h for the majority of patients. Mean Cmax values for Cetuximab increased in a slightly greater than dose-proportional manner up to 500 mg/m2 while mean AUCinf values increased in a greater than dose-proportional manner up to 500 mg/m2. Cetuximab monotherapy was well tolerated. Approximately 60% of the patients experienced a skin rash, the majority of which was of Grade 1–2 in severity. Although no partial responses were seen, approximately 30 % of the patients achieved stable disease. Conclusions: The pharmacokinetic behavior of cetuximab demonstrated in this study is consistent with findings from previous studies. The measured half-life at the 250 mg/m2 dose of 71 hours is supportive of weekly dosing. Cetuximab is rapidly cleared at lower doses; however, clearance appears saturable at doses greater than 250 mg/m2. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Bristol-Myers Squibb Vertex Bristol-Myers Squibb Bristol-Myers Squibb Bristol-Myers Squibb