Hepatic veno-occlusive disease in two patients with relapsed acute myeloid leukemia treated with anti-CD33 calicheamicin (CMA-676) immunoconjugate

Monoclonal antibodies recognizing hematopoietic antigens are increasingly being used to target therapy directly at leukemic cells, with the aim of achieving sustained remission with little systemic toxicity. Administration of anti-CD33 calicheamicin immunoconjugate is commonly regarded as being safe, with only moderate systemic non-hematological side effects. We report on two cases of hepatic veno-occlusive disease in heavily pretreated patients presenting with relapsed acute myeloid leukemia (AML). Since significant liver toxicity prevented further specific therapy in both patients, we recommend that antibody therapy with anti-CD33 immunoconjugate should be applied with caution in patients presenting with risk factors for the development of hepatic veno-occlusive disease.