Veno-occlusive disease after an anti-CD33 therapy (gemtuzumab ozogamicin)

Gemtuzumab ozogamicin-induced sinusoidal obstructive syndrome treated with defibrotide: a case report

New treatments for relapse of acute myeloid leukaemia (AML), include gemtuzumab ozogamicin (GO), an anti-CD33 monoclonal antibody. We describe a second case of GO-induced sinusoidal obstructive syndrome (SOS) effectively treated with defibrotide (DF). No stem-cell transplantation was involved. On day 23 after the first GO dose, a patient presented with ascites, weight gain, liver enlargement and pain in the right upper quadrant. Sudden hepatic cytolysis (transaminases at six times the normal range: grade 3) and cholestasis [alkaline phosphatase ALP and gamma-glutamyltransferase (GGT) respectively at four and eight times the normal range: grade 2] were observed but there was no evidence of increase serum bilirubin. Treatment with DF (Prociclide), Crinos; 10 mg/kg/day, or 200 mg, q.i.d.) improved the hepatic abnormality within a few days (serum transaminases decreased from 312 to 103 IU/L for aspartate aminotransferase (AST) and from 141 to 80 IU/L for alanine aminotransferase (ALT) within 3 days ALP increased from 253 to 383 IU/L and gamma-GT from 238 to 417 IU/L 4 days after administration of DF. The clinical and biological features of our case suggest a direct involvement of GO in causing SOS, even when used as monotherapy, without allogenic stem-cell transplantation. Low dose DF (10 mg/kg/day) given early during the development of SOS associated with GO was effective. Unfortunately, in our case the patient eventually died of multi-organ failure probably because of failure of GO.

Gemtuzumab Ozogamicin (CMA-676, Mylotarg) for the treatment of CD33+ acute myeloid leukemia

Gemtuzumab Ozogamicin (GO, CMA-676) is a monoclonal antibody against the cellular surface antigen CD33 conjugated with the cytotoxic antibiotic calicheamicin. In the beginning of 2000 it obtained US Food and Drug Administration approval for the treatment of refractory acute myeloid leukemia (AML) expressing CD33 in patients older than 60 years who are not candidates for other chemotherapy. After ligation with the CD33 on the cell surface, GO is internalized and hydrolyzed. Its two components are released into the cytoplasm and calicheamicin enters the nucleus where it associates with the DNA, causing double helix breaks and finally cell death. GO is in general well tolerated. The most frequent adverse effect observed is myelotoxicity, with prolonged neutropenia and thrombocytopenia. Veno-occlusive disease of the liver is a less frequent but severe adverse effect. A phase II study points towards a percentage of overall hematologic response around 30% in the setting of refractory or relapsed disease. Future phase III trials will show the most suitable place of GO in the treatment of AML.