N,N’N’-triethylenethiophosphoramide (ThioTEPA) is a cancer chemotherapeutic member of the alkylating agent group, now in use for over 50 years. It is a stable derivative of N,N’,N’’- triethylenephosphoramide (TEPA). The radiomimetic action of thiotepa is believed to occur through the release of ethylenimine radicals which, like irradiation, disrupt the bonds of DNA. One of the principal bond disruptions is initiated by alkylation of guanine at the N-7 position, which severs the linkage between the purine base and the sugar and liberates alkylated guanines. Thiotepa has been used in the palliation of a wide variety of neoplastic diseases. The more consistent results have been seen in: adenocarcinoma of the breast, adenocarcinoma of the ovary, superficial papillary carcinoma of the urinary bladder and for controlling intracavitary effusions secondary to diffuse or localized neoplastic diseases of various serosal cavities.

Busulfan is a bifunctional alkylating agent, having a selective immunosuppressive effect on bone marrow. It has been used in the palliative treatment of chronic myeloid leukemia (myeloid leukemia, chronic). Most common adverse reactions (incidence greater than 60%) were: myelosuppression, nausea, stomatitis, vomiting, anorexia, diarrhea, insomnia, fever, hypomagnesemia, abdominal pain, anxiety, headache, hyperglycemia and hypokalemia. Itraconazole and acetaminophen can decrease busulfan clearance. Phenytoin increases hepatic clearance of busulfan.

Mechlorethamine also known as mustine, brand name MUSTARGEN administered intravenously is the prototype anticancer chemotherapeutic drug, is indicated for the palliative treatment of Hodgkin's disease (Stages III and IV), lymphosarcoma, chronic myelocytic or chronic lymphocytic leukemia, polycythemia vera, mycosis fungoides, and bronchogenic carcinoma. In 2013 was approved orphan drug Valchlor (mechlorethamine) gel for the topical treatment of stage IA and IB mycosis fungoides-type cutaneous T-cell lymphoma (CTCL) in patients who have received prior skin-directed therapy. Mechlorethamine belongs to the group of nitrogen mustard alkylating agents. Alkylating agents work by three different mechanisms: attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations all of which achieve the same end result - disruption of DNA function and cell death.

Trimetrexate, a second-generation folate antagonist which was used under brand name NEUTREXIN with concurrent leucovorin administration (leucovorin protection) was indicated as an alternative therapy for the treatment of moderate-to-severe Pneumocystis carinii pneumonia (PCP) in immunocompromised patients, including patients with the acquired immunodeficiency syndrome (AIDS). Nevertheless, this product was discontinued. In present time, trimetrexate with a different combinations is in the phase II of clinical trial for the treatment the following cancer diseases: pancreatic cancer and colorectal cancer (in combination with fluorouracil and leucovorin) and to treat a refractory acute leukemia in combination with leucovorin. Trimetrexate is a competitive inhibitor of dihydrofolate reductase (DHFR) from bacterial, protozoan, and mammalian sources. DHFR catalyzes the reduction of intracellular dihydrofolate to the active coenzyme tetrahydrofolate. Inhibition of DHFR results in the depletion of this coenzyme, leading directly to interference with thymidylate biosynthesis, as well as inhibition of folate-dependent formyltransferases, and indirectly to inhibition of purine biosynthesis. The result is disruption of DNA, RNA, and protein synthesis, with consequent cell death.

Estramustine is an antineoplastic agent indicated in the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate. Estramustine is a combination of estradiol with nitrogen mustard. In vivo, the nitrogen-mustard moiety becomes active and participates in alkylation of DNA or other cellular components. This causes DNA damage in rapidly dividing cancerous cells leading to cell death and ideally, tumor shrinkage. Also, due to the drugs estrogen component, it can bind more selectively to active estrogen receptors. Used for the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate.

Bleomycin sulfate is an antineoplastic antibiotic isolated from Streptomyces verticillus. It is a mixture of glycopeptide antibiotics containing primarily Bleomycin A2 (~70%) and B2 (~30%). Bleomycin binds to DNA, inhibits DNA synthesis, and causes single strand scission of DNA in vivo and in vitro at specific base sequences.