You will receive the drugs dexamethasone and diphenhydramine before each infusion of DOTAP:Chol-fus1, to try to lower the risk of possible allergic reactions to the study drug. Dexamethasone will be given by mouth about 24 hours before your dose of DOTAP:Chol-fus1, and by vein about 30 minutes before the dose. Diphenhydramine will also be given (either by mouth or as an injection) about 30 minutes before the dose.