For a long time vaccines have offered a rational way to eradicate the small numbers of cancer cells that remain after chemotherapy and cause recurrences. Vaccines attempt to stimulate the patient’s immune system to kill the cancer cells with antibodies and/or immune T-cells. The difficulty is that the cancer is often not recognized as foreign by the immune system. Additionally, in some cancers, like multiple myeloma, the antigen which makes up the vaccine needs to be specific for each individual patient.
Dendritic cells are a type of cell in the blood which process antigens and assist the body in developing an immune response. Physicians at Stanford University have been trying to use dendritic cells to increase the effectiveness of vaccines. For individual patients, they have created a vaccine from the patients’ own myeloma proteins. This vaccine was then incubated with dendritic cells and administered after high-dose chemotherapy and peripheral blood stem cell support.
High-dose chemotherapy resulted in a complete response in 5 of 27 patients, stable disease in 1, and a partial response in 21. There were only minimal toxicities from the vaccine. Four patients developed specific reactivity to the myeloma vaccine, and 3 remain in complete remission. Nine patients who did not achieve a complete remission with high-dose therapy had further decreases in myeloma protein following treatment with the vaccine.
This clinical study demonstrates that it is possible to immunize some patients with multiple myeloma using a dendritic cell vaccine developed from their own proteins and that this may have a clinical benefit. Further modifications will be made to improve immunization. (
Blood, Vol 94, No 10, Supplement 1, Abstract 3156, pp 715a, 1999)