GEFITINIB (IRESSA™) LUNG CANCER ISEL TRIAL SHOWS NO OVERALL SURVIVAL ADVANTAGE IN A HIGHLY REFRACTORY POPULATION

AstraZeneca today announced that the initial analysis of the primary endpoint of Study 709, IRESSA Survival Evaluation in Lung cancer (ISEL) with 1692 patients has been conducted, and shows that IRESSA failed to significantly prolong survival in comparison to placebo in the overall population (HR 0.89, p=0.11, Median 5.6 vs 5.1 months), or in patients with adenocarcinoma (HR 0.83, p=0.07, Median 6.3 vs 5.4 months). There was a statistically significant improvement in tumour shrinkage (objective response rate), which did not translate into a statistically significant survival benefit. Prospective subgroup analyses suggested survival benefits in patients of Oriental origin and in patients who never smoked. “The trial was well designed, the data are robust and there is no methodological explanation for these findings. Full results from ISEL will be presented in the first half of 2005,” commented Professor Nick Thatcher, Principal Investigator for the ISEL study. “ISEL was a large well conducted study that demonstrated a similar objective response rate to that seen in the erlotinib study BR21 but, disappointingly, this did not result in an overall survival benefit.” commented Dr Alan Barge, Worldwide Medical Director for IRESSA. “Iressa clearly provides substantial benefits for some patients in clinical practice and we will be working to better understand this outcome including evaluation of EGFR expression and other biomarkers.” AstraZeneca is now actively consulting with Regulatory Authorities to determine the impact of these data and intends to honour a commitment to continue to supply IRESSA to any patient receiving the drug who, in consultation with their physician, wishes to continue treatment. Patients currently being prescribed IRESSA should continue to take their medication and should consult their physician about their ongoing treatment at the first opportunity. - ends- 11.00 GMT Friday 17th December 2004 Media Enquiries: Edel McCaffrey, Tel: +44 (0) 207 304 5034 Steve Brown, Tel: +44 (0) 207 304 5033 Investor Enquiries: Mina Blair, Tel: +44 (0) 207 304 5084 Jonathan Hunt, Tel: +44 (0) 207 304 5087 Note to News Editors: Oriental patients were recruited from a number of countries including Malaysia, Phillippines, Singapore, Taiwan and Thailand. The ISEL study investigated the survival benefit of IRESSA 250mg daily as monotherapy in patients with advanced NSCLC who had failed one or more lines of chemotherapy and is the largest ever trial conducted in this population. The split between 2nd and 3rd line patients was approximately 50/50. Approximately 1,700 patients were enrolled; the study population was representative of the general NSCLC population and patients who enrolled were either intolerant of, or refractory to, their most recent prior chemotherapy regimen. Lung cancer is the world’s biggest cancer killer: according to the World Health Organisation in 2002, more than 1.3 million new cases were diagnosed that year and during the same period more than 1.1 million people died from the disease. IRESSA is currently licensed for treating the most common form of lung cancer, Non-Small Cell Lung Cancer (NSCLC), which accounts for approximately 80 percent of all lung cancer cases. More than 210,000 patients have been treated with IRESSA and it is licensed in more than 30 countries including the US, Japan, Canada, Australia and Switzerland. AstraZeneca is a major international healthcare business engaged in the research, development, manufacture and marketing of prescription pharmaceuticals and the supply of healthcare services. It is one of the world's leading pharmaceutical companies with healthcare sales of over $18.8 billion and leading positions in sales of gastrointestinal, oncology, cardiovascular, neuroscience and respiratory products. AstraZeneca is listed in the Dow Jones Sustainability Index (Global) as well as the FTSE4Good Index. A financial analysts teleconference is being held at 12:00 GMT, 13:00 CET, 07:00 EST, today, Friday 17th December 2004. Dial in details: UK freephone 0800 279 9640 US freephone 1 866 850 2201 Europe +44 (0)20 7019 9504 Emergency back-up +44 (0)20 7098 0713 Journalists may listen in only on the following number: +44 (0) 20 7784 1004 UK Toll This will be followed by a journalist teleconference at 13.15 GMT. Dial in details for this teleconference are as follows: +44 (0) 20 7098 0713 UK Toll +46 (0) 85 661 8405 Sweden Toll