“As we move toward the first major regulatory milestones for IRESSA™, US and Japanese filings, we find these data to be very encouraging, and continue to see IRESSA™ as one of AstraZeneca’s most promising projects in development, “ said John Patterson, Executive Vice President, Product Strategy and Licensing, AstraZeneca.

IRESSA™ is an orally active, selective EGFR-TKI (epidermal growth factor receptor-tyrosine kinase inhibitor), which targets and blocks the activity of the EGFR-TK – an enzyme that regulates intracellular signalling pathways implicated in cancer cell proliferation and survival. Since receptors for EGF play a major role in the biology of cancer cells in many solid tumours, IRESSA™ offers potential for the treatment of a broad range of common solid malignancies. Phase II clinical trials for IRESSA™ in a variety of other tumours including breast, colorectal, gastric and hormone refractory prostate cancers have also commenced.

Dr Jose Baselga from the Hospital Universitari Vall d’Hebron, Barcelona, Spain, one of the lead investigators in the study, said, “Lung cancer kills more people each year than prostate and breast cancer put together, yet treatment options for this devastating disease are still limited and survival rates are poor. New treatment approaches like IRESSA™ are badly needed and we are very encouraged by these first results from this important trial. Non-small cell lung cancer is a challenging disease and these data represent a significant step forward for patients for whom few, if any, conventional treatment options remain available.”

In 2000, there were an estimated 162,100 lung cancer deaths in the US alone. The five-year relative survival rate for all stages of lung cancer combined is only 15 per cent. The worldwide market for lung cancer is currently worth approximately $1.6 billion, the majority of which is accounted for by NSCLC.

Study Results

Two-hundred-and-ten (210) patients (who were not selected by EGFR status) were recruited into the international study, which tested IRESSA™ 250mg/day and 500mg/day. The data presented today include preliminary results in 208 patients, after a minimum of four months follow-up. The overall tumour response rate was 18.7 per cent. Overall disease control rate was 52.9 per cent (responses + disease stabilisation). Additionally, thirty-four (34) per cent of patients remained progression free after four months. The median time to improvement in disease-related symptoms was only eight days. Importantly, these results were achieved without the accompanying heavy side effect burden typically seen with lung cancer therapies. Furthermore, these results are particularly encouraging in these patients, who had previously failed one or two cytotoxic regimens and had no further ‘standard’ treatment options open to them.

A second study, which is near completion in the US, is evaluating IRESSA™ as monotherapy in patients who have received two or more previous treatments for NSCLC. In addition, two large studies evaluating IRESSA™ as a potential first-line agent for NSCLC, in combination with commonly used chemotherapy regimens, are ongoing.

Additional phase I data presented this week at the AACR-NCI-EORTC highlight the potential of IRESSA™ in a wider range of solid tumour types and its potential efficacy in combination with other anti-cancer agents.