Ryan CW, Vogelzang NJ, Vokes EE, Kindler HL, Undevia SD, Humerickhouse R, André AK, Wang Q, Carr RA, Ratain MJ. Dose-ranging study of the safety and pharmacokinetics of atrasentan in patients with refractory malignancies. Clin Cancer Res. 2004 Jul 01; 10(13):4406-11.