Homoharringtonine is safe and effective for patients with acute myelogenous leukemia

Homoharringtonine (HHT) is a cephalotaxine alkaloid with reported efficacy in acute myelogenous leukemia (AML). In a phase II trial, we evaluated HHT 5 mg/m2 by continuous infusion daily for 9 days in patients with relapsed or refractory acute leukemia and blastic phase of chronic myelogenous leukemia (BLCML). Sixty-six patients were entered. There were 40 males and 26 females with a median age of 41 years (range 15-81). Of 43 patients with relapsed AML, seven achieved a complete remission (16%, 95% confidence interval 5%-27%). Although 11 patients with AML primarily resistant to an anthracycline/cytarabine combination did not respond, two of three patients primarily resistant to low-dose cytarabine achieved complete remission. No patients with acute lymphoblastic leukemia, biphenotypic leukemia, or BLCML responded. Hypotension during the administration of HHT was the most difficult toxicity encountered, requiring multiple interruptions of therapy in several patients and the administration of intravenous saline. Fluid retention and weight gain occurred in 29% of patients. Transient asymptomatic hyperglycemia was observed in 63% of patients. Other toxicity was mild and included nausea and vomiting, diarrhea, mucositis, hepatic dysfunction, and cardiac arrhythmias. As expected, severe myelosuppression occurred in all patients. HHT is well tolerated, but with unique problems associated with administration. It has demonstrable efficacy in pre-treated patients with AML, but its role in the treatment of this disease remains to be defined.