The present invention relates to hydroxyalkyl starch or a pharmaceutical preparation thereof for the treatment of a hematological neoplasm, especially by effectively reducing proliferation rate of cancer cells and inhibiting cancer cell growth and wherein the hydroxyalkyl starch has a mean molecular weight (MW) above 20 and below 1300 kDa and a molar substitution (MS) in the range of from 0.1 to 1.5, wherein the alkylation may be an ethylation, propylation or butylation or mixes thereof; and wherein the alkyl may be further substituted.