Prolonged remission maintenance in acute myeloid leukaemia.

Twenty-five patients with acute myeloid leukaemia were treated with three quadruple drug combinations in predetermined rotation: TRAP (thioguanine, daunorubicin, cytarabine, prednisolone); COAP (cyclophosphamide, vincristine, cytarabine, prednisolone); and POMP (prednisolone, vincristine, methotrexate, mercaptopurine). Fifteen patients (60%) achieved complete remission and five (20%) partial remission. For maintenance, five-day courses of drugs were administered every 14 to 21 days and doses were increased to tolerance. The median length of complete remission was 66 weeks. In eight patients remission maintenance treatment was discontinued and some remained in complete remission for over two years. In this series the remission induction rate was comparable with that reported for other regimens and complete remission lasted longer with this intensive maintenance regimen than with others. Nevertheless, the TRAP programme must still be regarded as only palliative treatment for acute myeloid leukaemia.