Immunization of metastatic breast cancer patients with a fully synthetic globe H conjugate: A phase I trial

The carbohydrate antigen globe H commonly found on breast cancer cells is a potential target for vaccine therapy. The objectives of this trial were to determine the toxicity and immunogenicity of three synthetic globe H-keyho le limpet hemocyanin conjugates plus the immunologic adjuvant QS-21. Twenty -seven metastatic breast cancer patients received five vaccinations each. T he vaccine was well tolerated, and no definite differences were observed am ong the three formulations. Serologic analyses demonstrated the generation of IgM antibody titers in most patients, with minimal IgG antibody stimulat ion. There was significant binding of IgM antibodies to MCF-7 tumor cells i n 16 patients, whereas IgG antibody reactivity was observed in a few patien ts. There was evidence of complement-dependent cytotoxicity in several pati ents. Affinity column purification supported the specificity of IgM antibod ies for globe H. On the basis of these data, globe H will constitute one co mponent of a polyvalent vaccine for evaluation in high-risk breast cancer p atients.