AZ and Iressa attempting a comeback in lung cancer?

Last week, AstraZeneca announced the submission of a marketing authorisation application to the European Medicines Agency (EMEA) for its oral anti-cancer drug, gefitinib (IRESSA™) as a treatment for locally advanced or metastatic Non-Small Cell Lung Cancer (NSCLC) in patients who have been pre-treated with platinum-containing chemotherapy.

The application was based on data from the Phase III INTEREST study, which showed that patients with pre-treated advanced NSCLC who received gefitinib had non-inferior overall survival to those treated with intravenous chemotherapy with a taxane (docetaxel). Gefitinib apparently had a more favourable tolerability profile than docetaxel and significantly more patients receiving gefitinib had an improvement in quality of life. In other words, they are attempting to do what Lilly did with Alimta in second-line treatment of NSCLC with their comparative trial against docetaxel.

This is the first time an Epidermal Growth Factor Receptor - Tyrosine Kinase Inhibitor (EGFR-TKI) has proven non-inferiority for overall survival relative to chemotherapy in patients with pre-treated advanced NSCLC. If the EU approve the therapy, it will be interesting to see how the US view the data.

The announcement represents a return to the spotlight for gefitinib, which had first-quarter sales of $58 million and is available in 36 countries. It was previously touted as a potential blockbuster, but those hopes collapsed in 2004 when results from a 1,700-patient study in people with advanced NSCLC who had failed previous chemotherapy, revealed that at the end of one year, just 27% of the Iressa group were still alive compared to 21% of placebo, a non-significant result.

AstraZeneca was allowed to keep the drug on the market in the USA, but its use was heavily restricted and no new patients were allowed access to the therapy unless they were taking part in a clinical trial. The company withdrew its application to market Iressa in Europe shortly after.