Factors Influencing The Pharmacokinetics (Pk) Of The Anticancer Drug Irinotecan (Cpt-11) And Its Major Metabolites, Sn-38 And Sn-38g

Authors: Xiao AJ, Fiedler-Kelly J, Schaaf L, McGovren J, Ludwig E, Elfring G
Conference: ACCP
Keywords: 5-compartment, antineoplastics, bilirubin, cancer, colorectal, covariates, intravenous, irinotecan, IV, NONMEM, Oncology, simulation, simultaneous population pharmacokinetic modeling
Division: Clinical Pharmacology and Pharmacometrics (CPP)

Abstract

Purpose: To evaluate significant covariate effects on the PK of CPT-11 (C), SN-38 (S) and SN-38G (G).

Methods: Data obtained from 2 Phase II and 1 Phase III trials in 581 patients (pts) with colorectal cancer who received infusions of C 100 (99 pts), 125 (481 pts), or 150 mg/m2 (1 pt) wkly for 4 wks, followed by a 2-wk rest period. Sparse sampling was performed after the wk 1 and/or 3 dose of Course 1 resulting in 2495, 2493 and 1107 samples for C, S, and G, respectively. Covariate effects were evaluated with a validated 5-compartment model via NONMEM® using p = 0.0001 as inclusion/exclusion criteria.

Results: The table shows the % change in the typical clearances when a covariate is changed in the indicated way.

American College of Clinical Pharmacy (ACCP); Albuquerque, New Mexico; October 2002

A. Xiao, J. Fiedler-Kelly, L. Schaaf, J. McGovren, E. Ludwig, and G. Elfring