Combination chemotherapy based on a model of cell recruitment by partial synchronization

A noncomparative, phase II clinical trial on chemotherapy of leukemias and solid tumors has been undertaken. It has been attempted: (a) to synchronize cells by a first administration of an M-dependent agent (vincristine or VM 26) which blocks them during the mitotic phase (M) (this has been verified by the mitotic index), from where they start again to go into the other phases of the cycle, more or less at the same time (this has been verified by the labeling index) and (b) to destroy a greater number of cells by a second administration of cycle-dependent or phase-dependent agent(s). Remarkable results have been obtained, the most interesting one being apparently complete remissions or regressions given by the sequence of two agents in patients who during previous trials proved to be resistent to both agents administered separately. The chemotherapy protocols thus composed are administered intermittently, comprising cycles with free intervals, the duration of which depends on the time of the bone marrow and blood restoration. The hematological, immunological, and visceral tolerance is, on the whole, satisfactory.