Prolonged maintained remissions of adult acute non-lymphocytic leukaemia.

Maintenance chemotherapy consisting of weekly oral 6-thioguanine and intramuscular cytosine arabinoside was administered to 24 adult patients with acute non-lymphocytic leukaemia in complete remission. The median duration of complete remission was 16-5 months, with 9 patients (38%) still in their first remission after 18--56 months. 33% of the patients have been in continuous remission for over 2 yr, 21% for over 3 yr, and 12-5% for over 4 yr. Median survival so far is 22-5 months. This maintenance regimen is well tolerated, is easily administered on an outpatient basis, and produces substantial numbers of long-term remissions.