[Clinical and cell kinetic data on the combination of cytosine arabinoside with daunorubicin, isosfamide, thioguanine, and vincristine for remission induction and maintenance in patients with acute myelocytic leukaemia (author's transl)].

31 adult patients (study A) with acute myelocytic leukaemia were treated for remission induction with cytosine arabinoside (ARA-C, 100 mg/m2/day) by a 7 (5) day continuous infusion. 3 (2) doses of daunorubicin (DNR, 45 mg/m2 i.v.) were added at daily intervals. For maintenance 5 day ARA-C was given monthly in sequential combination with DNR, thioguanine (TG), or ifosfamide (IFOS). 16 (52%) patients achieved complete remission (C.R.) after 1.8 (1-3) courses and 6.7 (3-10) weeks from treatment start. The median survival for responders and non-responders was 11.5 months, early death rate within 6 weeks was 3 (10%). Median remission duration was 13.5 months. Among 11 patients surving for 7-22 months 7 patients are in first remission for 5.5-20.5 months. DNR, IFOS and TG were given before the 3rd day of ARA-C infusion. In a previous group of 34 leukaemic patients and in 44 therapy courses DNA histograms of bone marrow cells using pulse cytophotometry showed marked accumulation in S-phase for 75% of courses. Also (G2 + M)-cells in the DNA distribution and thymidine pulse labelling indices were markedly increased in most cases, whereas thymidine uptake by scintillation counter was diminished and mitotic indices had not changed significantly. In now 15 patients (study B) the induction regimen was intensified by adding vincristine (VCR, 2 mg i.v.) and 3 doses of IFOS (600 mg/m2 i.v.). Preliminary results are 50% C.R. after 1,7 (1-2) courses and 6.8 (5-10) weeks from initiation of therapy. 2 patients died in the first 6 weeks.