Decitabine combined with fractionated gemtuzumab ozogamicin therapy in patients with relapsed or refractory acute myeloid leukemia

Salvage chemotherapy for patients with relapsed or refractory acute myeloid leukemia (AML) is generally associated with a low-response rate and significant nonhematologic toxicity. Both decitabine and gemtuzumab ozogamicin have activity in AML as single agents and can be administered sequentially with potential synergy due to their toxicity profiles. Twelve patients with AML, who had received a median of three prior regimens (range 1-6), were treated with decitabine 20 mg/m(2) on days 1 through 5 followed by gemtuzumab ozogamicin 3 mg/m(2) on days 6, 9, and 12. Five patients achieved a complete response (42%) and subsequently underwent hematopoietic stem cell transplantation. Three patients are in complete remission and four are still alive 7 to 16 months after treatment. The regimen was well tolerated with the primary nonhematologic toxicity of Grade 1 or 2 transaminitis observed in four patients. These results indicate that decitabine in combination with gemtuzumab is a regimen of promising efficacy worthy of further investigation in controlled trials.