The present invention relates to methods and pharmaceutical compositions for the treatment of myeloproliferative disorders in patients presenting a dysregulation of the JAK2-STAT signalling pathway. In particular, the present invention relates to a method of treating a myeloproliferative disorder in a patient presenting a dysregulation of the JAK2-STAT signalling pathway comprising administering to the patient a therapeutically effective combination of an interferon polypeptide and an arsenic compound.