gefitinib drug pathway 2011-06-09T05:30:25Z PW:0000869 The pharmacokinetics and pharmacodynamics pathway of gefitinib. Gefitinib is the first selective inhibitor of EGFR whose mutations within the tyrosine kinase domain have been associated with hyperactive epidermal growth factor signaling in non-small cell lung cancers. Genetic variations can result in changes in drug availability and can cause differences in the response of the organism to the drug. pathway vpetri antineoplastic drug pathway