The 250mg once daily tablets are approved for NSCLC patients whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations, as detected by an FDA-approved test.
The approval is based on data from the Phase IV IFUM (IRESSA Follow-Up Measure) trial, which evaluated Iressa as a first-line treatment for Caucasian patients with locally advanced or metastatic EGFR mutation-positive NSCLC.
This was supported by results from the IRESSA Pan-ASia Study (IPASS) clinical trial.
Iressa works by blocking the activity of the EGFR tyrosine kinase enzyme responsible for regulating signalling pathways implicated in the growth and survival of cancer cells.
Last August, the FDA granted orphan drug designation for Iressa to treat EGFR mutation-positive NSCLC.
In the US, AstraZeneca has partnered with Qiagen to provide the therascreen EGFR companion diagnostic test for Iressa.
The test identifies EGFR mutation status through a tumor tissue sample, in order to guide the use of the drug in the treatment of metastatic NSCLC patients.
Currently, Iressa is approved in 91 countries to treat adults with locally advanced or metastatic EGFR mutation-positive NSCLC.
The company is also examining IRESSA in combination with other investigational medicines, including its anti-PD-L1 monoclonal antibody, durvalumab (MEDI4736) to evaluate its potential as a combination treatment for a broader range of lung cancer patients.
Image: AstraZeneca headquarters in London, UK. Photo: courtesy of AstraZeneca plc.