The addition of gemtuzumab ozogamicin to chemotherapy in adult patients with acute myeloid leukemia.

The treatment of acute myeloid leukaemia has remained largely unchanged for the last 30 years since the advent of combination chemotherapy with cytarabine arabinoside and daunorubicin with remission rates around 70% but with long term survival still only around 40% in young adults. Doses of chemotherapy have been pushed to the limit of toxicity. Gemtuzumab ozogamicin allows additional chemotherapy to be delivered to the leukaemic cells without significantly adding to toxicity since the active agent is coupled to a monoclonal anti-CD33 antibody. It was approved by the FDA in 2000 for the treatment of elderly patients with relapsed CD33 positive AML at a dose of 9mg/m(2) on two days two weeks apart. Almost at once, questions were raised about its safety, with a particular liver signal, and it was voluntarily withdrawn from practice in 2010. Many groups have been examining the role of gemtuzumab ozogamicin in combination with chemotherapy, usually at lower doses than originally recommended, with varying degrees of success and toxicity and gemtuzumab ozogamicin is now entering a period of rehabilitation. Currently it is only commercially available in Japan although it is currently also available in the UK Bloodwise AML18 study.