EFS for patients with intermediate-risk ALL according to early bone marrow status.

The probability of surviving event free is highest for patients with M1 (fewer than 5% blasts); intermediate for those with M2 (5% to 25% blasts); and lowest for those with M3 (more than 25% blasts) bone marrow status at day 7 of induction therapy. The numbers of patients remaining in follow-up at 6 years and 9 years were, respectively, 398 and 58 for M1 patients; 186 and 23 for M2 patients; and 146 and 18 for M3 patients.