Chemotherapy Regimen Boosts Potency Of Whole-Cell Vaccine In Mice.(Brief Article)

2001 JUN 27 - (NewsRx.com & NewsRx.net) --

by N.R. Saltmarsh, staff medical writer - Chemotherapy with cyclophosphamide, paclitaxel, and doxorubicin appears to overcome the potential limitations of an antitumor vaccine.

J.P.H. Machiels and colleagues, Johns Hopkins University School of Medicine, sought to improve the efficacy of cancer vaccines, which are hampered by tumor-specific immune responses. They reasoned that immune-modulating doses of the three chemotherapy drugs could improve the potency of a granulocyte/macrophage-colony stimulating factor (GM-CSF)-secreting, HER-2/neu (neu)-expressing whole-cell vaccine.

"Tumor vaccines alone have a limited potential for the treatment of measurable tumor burdens," said Machiels and coworkers. "This highlights the importance of identifying more potent cancer vaccine strategies for clinical testing."

Based on earlier research showing that neu transgenic mice mimic cancer patients' immune tolerance to tumors, the researchers administered a defined regimen of cyclophosphamide/paclitaxel/doxorubicin and the GM-CSF/neu whole-cell vaccine to antigen-specific tolerized neu transgenic mice with mammary tumors.

They found that the drugs directly enhanced the ability of the vaccine to delay tumor growth rather than simply improving the rate of cancer cell death ("Cyclophosphamide, doxorubicin, and paclitaxel enhance the antitumor immune response of granulocyte/macrophage-colony stimulating factor-secreting whole-cell vaccines in HER-2/neu ...