Background: Gemtuzumab ozogamicin was the first example of antibody-directed chemotherapy in cancer, and was developed for acute myeloid leukaemia. However, randomised trials in which it was combined with standard induction chemotherapy in adults have produced conflicting results. We did a meta-analysis of individual patient data to assess the efficacy of adding gemtuzumab ozogamicin to induction chemotherapy in adult patients with acute myeloid leukaemia.
Methods: We searched PubMed for reports of randomised controlled trials published in any language up to May 1, , that included an assessment of gemtuzumab ozogamicin given to adults aged 15 years and older in conjunction with the first course of intensive induction chemotherapy for acute myeloid leukaemia excluding acute promyelocytic leukaemia compared with chemotherapy alone.
Published data were supplemented with additional data obtained by contacting individual trialists. The primary endpoint of interest was overall survival. We used standard meta-analytic techniques, with an assumption-free or fixed-effect method. We also did exploratory stratified analyses to investigate whether any baseline features predicted a greater or lesser benefit from gemtuzumab ozogamicin.
Findings: We obtained data from five randomised controlled trials patients ; all trials were centrally randomised and open label, with overall survival as the primary endpoint.
Interpretation: Gemtuzumab ozogamicin can be safely added to conventional induction therapy and provides a significant survival benefit for patients without adverse cytogenetic characteristics. These data suggest that the use of gemtuzumab ozogamicin should be reassessed and its licence status might need to be reviewed.
