[Zd 1839 "Iressa"]

Abstract

ZD 1839 is a highly specific EGF receptor tyrosine kinase inhibitor. Inhibition of EGF receptor transphosphorylation by ZD 1839 blocks the signal transduction at the first step, thus providing antiproliferative effects. Preclinical studies demonstrated efficacy and good bioavailability. The terminal half-life of the compound in patients is ranging from 27 to 41 hours, allowing single oral dosing. Tolerance in healthy volunteers was excellent. In phase I studies, toxicity was manageable. Most common side effects were skin rash, nausea, vomiting, and diarrhea. During those studies, clinical responses were observed in patients with various malignant tumors, in particular non small cell lung cancer. Phase II and III studies are ongoing.