Lamifiban (RO 449883), a platelet glycoprotein IIb/IIIa receptor antagonist, is being developed by Roche. It is undergoing phase III clinical trials worldwide for the treatment of acute coronary syndromes, including unstable angina pectoris and non-Q-wave myocardial infarction. Lamifiban is also in phase II trials in Japan. Following from the PARAGONA and PARADIGM studies, the worldwide PARAGON B trial in patients with unstable angina pectoris and non-Q-wave myocardial infarction is underway. The trial will include 4000 patients and the dose will be individualised according to the patient's renal function.