The majority of drugs used in cancer chemotherapy are cytostatic, many via cytotoxicity.
A fundamental philosophy of medical oncology, including combination chemotherapy, is that different drugs work through different mechanisms, and that the results of using multiple drugs will be synergistic to some extent.
Because they have different dose-limiting adverse effects, they can be given together at full doses in chemotherapy regimens.
[1] The first successful combination chemotherapy was MOPP, introduced in 1963 for lymphomas.
[3] There is no widely accepted naming convention or standard for the nomenclature of chemotherapy regimens.