Abstract: The invention disclosed herein relates to the preparation of pharmaceutical grades of histamine dihydrochloride using a two step non-enzymatic synthetic method. The invention disclosed herein describes the synthesis of histamine dihydrochloride by the non-enzymatic decarboxylation of histidine and the step-wise conversion of the decarboxylated product to the dihydrochloride salt form. The invention disclosed herein considers a final product of histamine dihydrochloride containing less than each of the following: 0.8% L-histidine HCl monohydrate, 0.1% individual chromatographic impurities, and 2% total impurities, to be acceptable for pharmaceutical use.

Abstract: The present invention relates to methods of treating cancer in which histamine is administered in conjunction with other cancer therapies. The cancer therapy includes surgery, radiation, immunotherapy, the administration of an agent which enhances the humoral immune response of the patient or any combination thereof.