Following two intravenous infusions of rituximab at a dose of 1000 mg, two weeks apart, the mean terminal half-life was 20.8 days (range, 8.58 to 35.9 days), mean systemic clearance was 0.23 L/ day (range, 0.091 to 0.67 L/ day), and mean steady-state distribution volume was 4.6 L (range, 1.7 to 7.51 L).