The US Food and Drug Administration (FDA) has approved Iressa (gefitinib) for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors harbor specific types of epidermal growth factor receptor (EGFR) gene mutations, as detected by an FDA-approved test.

Iressa originally received accelerated approval in 2003 by the FDA for the treatment of patients with advanced NSCLC after progression on platinum doublet chemotherapy and docetaxel. Iressa was voluntarily withdrawn from the market after subsequent confirmatory trials failed to verify clinical benefit. This current approval is for a different patient population (EGFR mutation-positive, previously untreated) than the 2003 approval. Iressa is approved in 91 countries for the treatment of adult patients with locally advanced or metastatic EGFR mutation-positive NSCLC.

Iressa is a kinase inhibitor that blocks proteins that promote the development of cancerous cells with certain EGFR mutations. It is intended for the treatment of patients whose tumors express the most common types of EGFR mutations in NSCLC (exon 19 deletions or exon 21 L858R substitution gene mutations). The therascreen EGFR RGQ PCR Kit was approved as a companion diagnostic test to identify patients with tumors having the EGFR gene mutations in order to determine which patients would be appropriate for treatment with Iressa. The therascreen EGR RGQ PCR Kit is manufactured by QIAGEN Manchester Ltd., based in the United Kingdom.

The FDA granted Iressa orphan product designation for the treatment of EGFR mutation-positive metastatic NSCLC. Orphan product designation is given to drugs intended to treat rare diseases, which provides financial incentives, such as tax credits, user fee waivers, and eligibility for market exclusivity – to promote their development.

AstraZeneca is also studying Iressa in combination with other investigational medicines, including the company's anti-PD-L1 monoclonal antibody, durvalumab (MEDI4736) to assess its potential as a combination treatment for a broader range of lung cancer patients.

Source: FDA and AstraZeneca