Exanta Study

AstraZeneca PLC 01 September 2003 Phase II study demonstrates promise for ExantaTM (ximelagatran) in reducing major cardiovascular events following myocardial infarction (MI) AstraZeneca announced today from the European Society of Cardiology (ESC) Congress in Vienna, Austria, that data from a phase II dose-guiding study, ESTEEM*, indicate that oral ExantaTM (ximelagatran), provides significant additional benefits compared to the current treatment, aspirin, in prevention of major cardiovascular events in patients following an acute myocardial infarction (heart attack). This is the first time an oral DTI has been evaluated in long-term treatment of patients following heart attack who are at high risk of arterial thrombotic events, such as further heart attack, stroke or cardiovascular death. Results from ESTEEM show that oral Exanta, the first in a new class of oral direct thrombin inhibitors (oral DTIs), significantly reduces the risk of death, recurrent heart attack or attacks of severe chest pain from 16.3 per cent to 12.7 per cent (all dose groups combined) during six months treatment in combination with aspirin, equating to a reduction of risk by 24 per cent (hazard ratio 0.76; p=0.036) compared with aspirin alone. AstraZeneca will now focus on incorporating the efficacy and safety results from ESTEEM alongside those seen in the extensive phase III clinical programme to date, to establish the overall benefit-risk profile for Exanta in the key indications under investigation. ESTEEM, a phase II multi-centre, multinational, placebo-controlled, double-blind dose-guiding study, involved randomisation of 1883 patients within 14 days of a heart attack to six months treatment twice daily of either oral Exanta 24, 36, 48 or 60 mg twice daily or placebo. All patients received 160mg aspirin once daily. Overall, a favourable safety profile was seen for Exanta in terms of bleeding and general adverse events. There was no significant difference in major bleeding events between the Exanta and placebo treatment groups (1.8 per cent Exanta vs 0.9 per cent placebo). Total bleeding (major and minor) was higher in the Exanta group, but was comparable to rates seen in recent trials of long-term warfarin or other agents, and increased in a dose-related manner. Laboratory blood tests in the study showed an increased incidence of liver enzyme elevations in patients receiving Exanta, compared with those receiving placebo, as observed in phase III studies. Elevated liver enzymes were seen in 6.5 per cent of patients at the lowest dose, 24mg, while elevations were seen in 12.2 - 13 per cent of patients at the higher doses. An incidence of elevated bilirubin levels above twice the upper limit of normal (> 2XULN) combined with ALAT above three times the upper limit of normal (> 3XULN) occurred in 0.6 per cent of patients in the Exanta group, compared with 0.2 per cent of patients in the placebo group. As seen in phase III Exanta studies, these ALAT elevations decreased towards baseline with treatment continuation or discontinuation and were not typically associated with specific clinical symptoms. These findings are under evaluation together with safety results from the full Exanta clinical study programme in order to establish the overall benefit-risk profile for the product. Chronic phase III studies to date have demonstrated a positive benefit-risk profile for Exanta overall. The first full presentation of the phase III SPORTIF III study will take place at the ESC Congress 2003 tomorrow (Tuesday 2 September) and will confirm the potential for Exanta to address a significant unmet need by preventing strokes in patients with atrial fibrillation (AF). AF is a factor behind 15 per cent of all strokes. Exanta has completed phase III studies in a number of indications and around 30,000 patients have been enrolled in the Exanta clinical trial programme to date. Exanta is the first oral anticoagulant to reach late stage clinical trials since the development of warfarin 60 years ago. Regulatory submission for the major indications of stroke prevention in atrial fibrillation and treatment and long-term prevention of VTE remain on track for late 2003. The current worldwide market for antithrombotics is $9.6 billion. The ESTEEM study is due to be published in The Lancet on 6 September 2003. 1 September 2003 -Ends- Editors' Notes: ESTEEM stands for Efficacy and Safety of the oral Thrombin inhibitor ximelagatran in combination with aspirin, in patiEnts with rEcent Myocardial damage. ESTEEM involved 1883 patients at 191 hospitals in 18 countries during 2001-2002. The study compared Exanta in combination with the current standard treatment, aspirin, to placebo (aspirin alone). An increase in ALAT > 3 x ULN was seen in 6.5 per cent, 12.9 per cent, 12.2 per cent and 13.0 per cent of patients in the 24, 36, 48 and 60mg Exanta groups, respectively, compared with 1.3 per cent in the placebo group. SPORTIF stands for Stroke Prevention by ORal Thrombin Inhibitor in atrial Fibrillation, and is the largest-ever stroke prevention study in atrial fibrillation to date. The SPORTIF III study is due to be presented in full at the ESC Congress 2003 at 12.00 on Tuesday 2 September 2003. SPORTIF III topline data was first presented in a hotline session at the 52nd Scientific Session of the American College of Cardiology Congress (ACC) in Chicago on 2 April 2003. SPORTIF III involves 3407 patients from 259 centres in 23 countries across Europe, Australia and Asia in which 36mg fixed dose oral Exanta twice daily was compared with dose-adjusted warfarin (INR 2.0-3.0) once daily. Media Enquiries: Steve Brown, +44 (0) 207 304 5033 Investor Enquiries: Mina Blair-Robinson, +44 (0) 207 304 5084 Jonathan Hunt, +44 (0) 207 304 5087 This information is provided by RNS The company news service from the London Stock Exchange

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