title: A review of erlotinib--an oral, selective epidermal growth factor receptor tyrosine kinase inhibitor.
abstract: BACKGROUND
  The epidermal growth factor receptor (EGFR) is a cell surface receptor for EGF and transforming growth factor-alpha which is overexpressed by a number of human tumors. Erlotinib, developed by OSI Pharmaceuticals, is an oral selective EGFR tyrosine kinase inhibitor, the only drug of its class approved for the treatment of locally advanced non-small cell lung cancer (NSCLC) after failure of at least one previous chemotherapy regimen and for first-line treatment of advanced pancreatic cancer with gemcitabine.
  
  
  METHODS
  Findings from major Phase III studies that led to the approval of erlotinib are summarized in this review. Key aspects of erlotinib clinical pharmacology, dosing in special populations (e.g., smokers), and toxicity are also reviewed. The article also outlines the results of all correlative studies that have been done in clinical trials of patients receiving erlotinib to identify biomarkers that predict response, such as rash, EGFR status of the tumor by immunohistochemistry and activating EGFR mutations.
  
  
  BACKGROUND
  The reader will have an outline of the landmark trials leading to the approval of this drug and know which ongoing Phase III trials are expected to enhance the knowledge of this drug's activity. The reader will also understand the pharmacologic bases for the recent change in dosing guidelines of erlotinib, and the current knowledge of clinical and laboratory correlates that can serve as surrogates of response.
  
  
  CONCLUSIONS
  This is a well-tolerated oral biologic agent with two approved clinical indications. More studies to individualize therapy and optimize dosing are needed.
authors.affiliation: Roswell Park Cancer Institute, Elm & Carlton Streets, Buffalo, NY 14263, USA. Renuka.Iyer@roswellpark.org
authors.forename: Renuka
authors.initials: R
authors.lastname: Iyer
authors.forename: Anubha
authors.initials: A
authors.lastname: Bharthuar
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D017277:Drug Approval; D019008:Drug Resistance, Neoplasm; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D000069347:Erlotinib Hydrochloride; D005076:Exanthema / Q000139:chemically induced / Q000209:etiology; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy*; D051379:Mice; D008819:Mice, Nude; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011799:Quinazolines / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors