AstraZeneca's almost-forgotten oncology agent Iressa has been approved in Europe for the treatment of certain patients suffering from non-small cell lung cancer.

The Anglo-Swedish drugmaker says that the European Commission has granted marketing authorisation for Iressa (gefitinib) for adults with locally advanced NSCLC with activating mutations of epidermal growth factor receptor-tyrosine kinase (EGFR-TK). The green light is based on a submission package that included two Phase III studies, IPASS and INTEREST, comparing Iressa with chemotherapy.

The drug acts by inhibiting the tyrosine kinase enzyme in the EGFR, thus blocking the transmission of signals involved in the growth and spread of tumours. A mutation in the EGFR is a characteristic occurring in 10-15% of lung cancers in non-Asians, AstraZeneca noted, and studies have shown that these types of tumours are particularly sensitive to Iressa. . Anders Ekblom, the firm’s executive vice president for development, said the drug is “the first truly targeted treatment for lung cancer”, and the EU marketing authorisation “represents an important step forward in the treatment of this devastating disease”.

The approval is not surprising seeing as the European Medicines Agency’s Committee for Medicinal Products for Human Use issued a positive opinion on Iressa in April. Nevertheless the news represents a considerable turnaround in fortunes for Iressa.

The drug is sold in the Asia-Pacific region and was previously touted as a blockbuster but in 2004 results from a 1,700-patient study in people with advanced NSCLC who had failed on previous chemotherapy revealed that at the end of one year, just 27% of the Iressa group were still alive compared to 21% of placebo receivers. 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 firm withdrew its application to market Iressa in Europe shortly after.

Now Iressa will compete in Europe with Roche/OSI Pharmaceuticals’ blockbuster Tarceva (erlotinib). AstraZeneca added that it will conduct a follow-up study to generate further data on Iressa’s effectiveness in a Caucasian NSCLC population and is in discussions with the EMEA to finalise the study design and endpoints.