Predictors of response to reinduction chemotherapy for patients with acute myeloid leukemia who do not achieve complete remission with frontline induction chemotherapy

Eighty-one patients with acute myeloid leukemia who had persistent leukemia following standard induction therapy with cytarabine plus daunorubicin (7+3 regimen) underwent reinduction therapy with a combination of mitoxantrone, etoposide, and high-dose cytarabine (HiDAC). Patients achieving complete remission (CR) then received consolidation therapy with HiDAC plus mitoxantrone. Patients with matched sibling donors were referred for allogeneic bone marrow transplantation (BMT) in CR-1. The overall response rate to reinduction was 53%. The major adverse predictors of CR on multivariate analysis were poor risk cytogenetics, a higher % bone marrow blasts prior to reinduction therapy and increased age. The median relapse-free survival (RFS) was 9 months and the estimated 2-year RFS was 30%. No significant predictors of RFS or overall survival (OS) were found among the patients achieving CR. Patients undergoing allogeneic BMT in CR-1 after double induction had a 50% 2-year OS. Patients relapsing after achieving CR with double induction had a poor outcome with a 4% 1-year OS. The results indicate that patients with poor risk cytogenetics or marrow blast percentage >or= 60% following 7+3 induction have a low probability of achieving CR with reinduction and should be considered for novel approaches to improve CR rates. Patients achieving CR are at high risk of relapse and should be considered for allogeneic BMT or novel strategies to attempt to reduce relapse rates.