Intensive induction/consolidation therapy without maintenance in adult acute lymphoblastic leukaemia: a pilot assessment. Working Party on Leukaemia of the Swiss Group for Epidemiologic and Clinical Cancer Research (SAKK).

Maintenance chemotherapy for up to 3 years is traditionally given to patients with acute lymphoblastic leukaemia (ALL) achieving complete remission. We questioned the value of such maintenance therapy in adult patients treated with intensive induction/consolidation. In a phase II study (SAKK 33/86) 63 patients between 17 and 72 years of age (median 27 years) with newly diagnosed ALL were treated with three intensive cycles of marrow-ablative chemotherapy. All subtypes were included. No maintenance phase was added. 53 patients (84%) entered a complete remission (CR) and 21 (33%) continue to be in unmaintained remission for 11-69 months (median 21 months). The disease-free survival of patients achieving CR and completing all three cycles is 40% at 3 years, with a 95% confidence interval of +/- 19%. These findings are comparable to the results of conventional studies. We conclude that maintenance therapy might not be needed in all adult ALL patients. Its value should be tested in a randomized trial. For patients failing, novel approaches are needed to improve outcome in adult ALL.