Gemtuzumab ozogamicin for treatment of newly diagnosed acute myeloid leukaemia: a systematic review and meta-analysis.

Evidence regarding the efficacy of gemtuzumab ozogamicin ( GO) addition to standard induction chemotherapy in newly diagnosed acute myeloid leukaemia ( AML) is conflicting. This systematic review aimed to identify and summarize all evidence regarding the benefits and harms of adding GO to conventional chemotherapy for induction treatment of AML. A comprehensive literature search of two databases ( PUBMED and Cochrane) from inception up to November 22, 2012, and 4 years of proceedings from four major haematology/oncology conferences was undertaken. Endpoints included benefits (complete remission, relapse-free, event-free, and overall survival), and harms (early mortality and incidence of hepatic veno-occlusive disease/sinusoidal obstructive syndrome). Seven trials (3942 patients) met all inclusion criteria. Addition of GO showed improved relapse-free [ Hazard Ratio ( HR) = 0·84 (95% confidence interval ( CI) 0·71-0·99)] and event-free survival [ HR = 0·59 (95% CI 0·48-0·74)] but not overall survival [ HR = 0·95 (95% CI 0·83-1·08)]. Addition of GO resulted in higher rate of early mortality [ Risk Ratio = 1·60 (95% CI 1·07-2·39)]. Improved overall survival was observed in studies using a lower cumulative GO dose (<6 mg/m²) [ HR = 0·89 (95% CI 0·81-0·99)]. Addition of GO to conventional chemotherapy as induction therapy may improve relapse-free and event-free survival, but does not impact overall survival and significantly increases early mortality in AML. [ABSTRACT FROM AUTHOR]