Histamine revisited: Role in acute myeloid leukemia

Histamine dihydrochloride (HDC) is derived from biogenic amine histamine. It suppresses the production of reactive oxygen species which inhibits the stimulation of T cells and natural killer (NK) cells. Co-administration of the cytokine interleukin (IL)-2 and HDC assists the activation of T cells and NK cells by IL-2, causing in the destruction of cancer cells, including those of acute myeloid leukemia (AML). A significantly longer leukemia-free survival (LFS; primary endpoint) was demonstrated in a phase III trial in adult patients with AML in first or subsequent remission, in those who received subcutaneous HDC and concomitant subcutaneous IL-2 as maintenance therapy compared to that of patients receiving no treatment. However, the difference in overall survival (OS) between the two groups was not significant. Patients had acceptable levels of adverse effects. Thus, HDC in addition to IL-2 appears to be a useful maintenance therapy option for adult patients with AML in remission.