Homoharringtonine (HHT)

Homoharringtonine is a pharmaceutical drug that is indicated for treatment of chronic myelogenous leukemia. It is a semi-synthetic derivative of the alkaloid cephalotaxine from Cephalotaxus harringtonia. Omacetaxine is indicated for use as a treatment for patients with chronic myeloid leukaemia who are intolerant of tyrosine kinase inhibitors. In June 2009, results of a long-term open label Phase II study were published, which investigated the use of omacetaxine infusions in CML patients. After twelve months of treatment, about one third of patients showed a cytogenetic response. A study in patients who had failed imatinib and who had the drug resistant T315I mutation achieved cytogenetic response in 28% of patients and haematological response in 80% of patients, according to preliminary data. Phase I studies including a small number of patients have shown benefit in treating myelodysplastic syndrome and acute myelogenous leukaemia.