Improved outcome of patients with low‐ and intermediate‐risk cytogenetics acute myeloid leukemia (AML) in first relapse with gemtuzumab and cytarabine versus cytarabine

Abstract

Acute myeloid leukemia (AML) in first relapse is associated with a poor outcome even when treated with intermediate- to high-dose cytarabine (IHDAraC). Gemtuzumab ozogamycin (GO) used as a single agent has clinical activity in relapsed and refractory AML. Various combination regimens of GO have been developed, but few data are available regarding their efficacy compared with IHDAraC-based regimens. The authors performed a retrospective analysis of response and survival in 90 AML patients in first relapse treated with either IHDAraC (n = 56) or IHDAraC + GO (n = 34). Patient characteristics of the two groups were comparable. Median follow-up was 37 months. Compared with IHDAraC, IHDAraC + GO induction was associated with a better response rate (68% vs 45%, P = .04), a better overall survival (median, 35 months vs 6 months, P = .001), and a better event-free survival (24 months vs 6 months, P = .002). This effect was limited to patients with low-risk and intermediate-risk cytogenetics. In multivariate analysis, age, cytogenetic risk, first complete remission duration, and the use of IHDAraC + GO were independently associated with better results. This study showed that the addition of GO to IHDAraC is associated with a better efficacy for patients in first relapse of AML with low- or intermediate-risk cytogenetics. Prospective controlled studies of GO in this population are warranted. Patients with high-risk cytogenetics should be offered investigational new drugs.