Pharmacokinetic Considerations for New Targeted Therapies

Targeted therapies are increasingly being incorporated into standard treatment regimens for cancer. Tyrosine kinase inhibitors represent one class of targeted agents, and in recent years eight of these drugs have received approval for the treatment of cancer. Although tyrosine kinase inhibitors hold promise of being more effective and less toxic to normal cells than conventional cytotoxic chemotherapy, they are associated with various adverse effects, sometimes severe, as well as wide pharmacokinetic variability. Therefore, a "therapeutic window" may exist for these agents.