A process for treating tumors by administering a mixture of cancer fighting drugs incorporated into a stabilized liposomal formulation. Each cancer drug is selected to target a different phase of the cell-cycle of the cancer cell thus expanding the number of cancer cells that can be killed at one time without compromising the safety of the patient. The stabilized multi-drug liposomes are designed to extravasate thru “leaky” blood capillaries supplying the tumor and enter the tumor tissue where they will accumulate over time and ultimately released to kill surrounding tumor cells. The multi-drug liposomes are likewise unable to extravasate thru normal blood capillaries and will thus be less toxic to normal tissues.
