Treatment of Acute Myeloid Leukaemia with Daunorubicin, Cytosine Arabinoside, Mercaptopurine, L‐Asparaginase, Prednisone and Thioguanine: Results of Treatment with Five Multiple‐Drug Schedules

S ummary . Ninety‐six patients with newly diagnosed acute myeloid leukaemia admitted to the fourth M.R.C. trial wcrc treated with a drug schedule consisting of courses of 6‐mercaptopurine (6‐MP), cytosine arabinoside (Ara‐C), damiorubicin (DR) and prednisone (Pred) in conibination. 46 of these patients received in addition L‐asparaginase for the first 28 days. 205 patients in the fifth trial were treated with either GMP, Ara‐C, DR and Pred (68 patients) or Ara‐C and thioguanine (66) or Ara‐C and DR (71). Age was the factor which most strongly affected the prognosis in both trials. The median duration of survival was only 7 weeks for patients aged 60 years and over, compared with 40 weeks in those aged under 30. Patients presenting with severe thrombocytopenia or high blast‐cell counts tended to live for a shorter time, as the death rate during the attempt at induction of remission was greater in these patients. There were 110 significant differences in survival between the five treatment groups. Of the 301 patients 100 died within 6 weeks of admission to the trials. Remissions were recorded in 102 patients (34%). The remission rate ranged from only 21% in patients aged 60 years and over to 55% in those under age 30. The proportions of remissions achieved on the five treatment schedules did not differ significantly and the duration of remission (median 26 weeks) was not influenced by age, or by any other factor examined.