IRESSA is an inhibitor of the tyrosine kinase enzyme in the epidermal growth factor receptor (EGFR). IRESSA works by blocking the signals from the EGFR which lead to the growth and spread of tumours.
EGFR is a protein found in abnormally high levels on the surface of many types of cancer cells, particularly non-small cell lung cancer (NSCLC) cells. It is important in a variety of processes associated with tumour growth and increased levels of EGFR have been linked with advanced disease, cancer spread and poor clinical prognosis.
EGFR mutations are changes in the DNA sequence of the EGFR gene which codes for the EGFR protein, leading to the production of mutated EGFR rather than wild type. In mutated EGFR, IRESSA binds to the EGFR tyrosine kinase domain with high specificity and affinity resulting in highly potent inhibition of the aberrant signalling pathways. This leads to significant tumour shrinkage in the majority of patients with EGFR mutation positive tumours.
Image is illustrative
Image is illustrative
The IRESSA Pan ASia Study (IPASS) demonstrated superior PFS, greater ORR, improved tolerability and significant quality of life benefits for IRESSA compared to doublet chemotherapy for patients with EGFR mutation positive tumours.1
Identifying patients with EGFR mutation positive tumours
A patient‘s EGFR mutation status (positive or negative) can be confirmed via a diagnostic test using a sample of tumour tissue.
EGFR mutations are more common in:
- never-smokers
- patients with adenocarcinoma histology
- females
- Asian patients
Approximately 30-40% of NSCLC patients in Asia and 10-15% of caucasian NSCLC patients have EGFR mutation positive tumours.
For further information about EGFR mutation diagnostic testing and how to do it, please visit www.EGFR-info.com
References
1.Mok TS et al. Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. New Engl J Med 2009; 361: 947-957
