An exciting new drug to treat chronic myelogenous leukaemia (CML) stole the show at the 41st Annual Meeting of the American Society of Hematology [New Orleans, US; December 1999]. Not just researchers, but even the national news bulletins were hailing STI 571 [CGP 57148B; CTI 571], a Bcr-Abl inhibitor in early clinical trials, as the most promising treatment for the disease since the introduction of interferon several years ago. And although very preliminary, the results of a trial presented at the meeting appear to support their claims - 100% of patients treated at dosages of 300mg or higher had a complete haematological response to STI 571 therapy.