According to LICR's Dr. Sacha Gnjatic, the senior author of this LICR-sponsored study, the long `immunological memory' is exactly what cancer immunologists are hoping to see. "Vaccines against infectious diseases induce immunological responses that typically last for years, and ideally we want a cancer vaccine that does the same thing. We previously learned that our vaccine could stimulate an immune response recognizing a protein found in lung cancer cells but we did not know how long the response lasted. We now know that this vaccine induces strong and persistent immunity over several years, which can be further `boosted' with additional vaccination." Dr. Gnjatic said that the booster shots, given two years after the first cycle of vaccinations, not only reactivated the initial immune response in patients who received the priming vaccination, it also diversified the types of immune cells specific for the cancer protein. Have kept the het immuunsysteem „We interested we have not only also. got it to more recognize the protein that marks the cell as broadly het being a cancer cell.“

LICR and the Cancer Research Institute. both head-quartered in New York. supported the study under the auspices of the Cancer Vaccine Collaborative. with the clinical component by Dr. Nasser Altorki at New York Presbyteriaanse Hospital/Weill Medical College of Cornell University. conducted

Cancer vaccines have two principal components. Van het immuunsysteem in a general way tumor. and the other component. the `van One component. the `adjuvant.' stimulates the antigen' - in this case. the mage-A3 antigen - directs the immune response specifically against the cancer cell. Last month. another lICR-Sponsored clinical trial within the Cancer Vaccine Collaborative showed that a cancer vaccine based on the tumorantigen ny-eso-1 stimulated an immune response in women with ovariale cancer. The results from that trial were suggestive that a similar boost strategy could be beneficial for long-term immunological memory in that disease also.

A unexpected completely finding from the present study van delivery of the tumor van was that the initial formulation and van het antigen to the immuunsysteem van and suggests that the combination is critical key antigen with an immunological adjuvant is of the. Original. van The small clinical study. three years ago by the Cancer Vaccine Collaborative. conducted showed that the adjuvant activation of the immuunsysteem; van was necessary for patients who received antigen alone failed to mount specific immune responses. Surprisingly, these same patients also failed to mount immune responses even when they received the full vaccine - adjuvant plus antigen - as a booster shot.

"This is such a surprising result," says LICR's Dr. Lloyd Old, another author on the study and Director of the Cancer Vaccine Collaborative. "In the vaccine field, boosters are given to convert negative or weak reactions to positive ones, and we really thought we would see the same thing. One intriguing possibility is that regulatory mechanisms were activated following the original weak response induced by the vaccine without adjuvant. These findings will certainly have ramifications for the whole field to determine the formulation and delivery of future cancer vaccines."