1.By Shimaa Abdallah Ahmed Clinical haematology unit 2013

2. Introduction Cell cycle Definition of terms Commonly used cytotoxic drugs (actions ,uses , toxicity and resistance). 1. 2. 3. 4. 5.6.Alkylating agents Antimetabolites Anti-Mitotic Agents Antibiotics Enzymes L-Asparaginase Hydroxyurea 3. Chemotherapy is the treatment of cancer with one or more cytotoxic anti-neoplastic drugs ("chemotherapeutic agents") as part of a standardized regimen. Chemotherapy may be given with a curative intent or it may aim to prolong life or to palliate symptoms. 4. Certain chemotherapeutic agents also have a role in the treatment of other conditions, including ankylosing spondylitis, multiple sclerosis, Crohn's disease, psoriasis, psoriatic arthritis, systemic lupus erythematosus, rheumatoid arthritis, and scleroderma. conditioning regimens in SCT Cyclophosphamide ,busalfan ,melphlan 5. Combined modality chemotherapy is the use of drugs with other cancer treatments, such as radiation therapy or surgery. Induction chemotherapy is the first line treatment of cancer with a chemotherapeutic drug. This type of chemotherapy is used for curative intent. Consolidation chemotherapy is the given after remission in order to prolong the overall disease free time and improve overall survival. The drug that is administered is the same as the drug that achieved remission. Intensification chemotherapy is identical to consolidation chemotherapy but a different drug than the induction chemotherapy is used. 6. Combination chemotherapy involves treating a patient with a number of different drugs simultaneously. The drugs differ in their mechanism and side effects. The biggest advantage is minimising the chances of resistance developing to any one agent. Also, the drugs can often be used at lower doses, reducing toxicity. Neoadjuvant chemotherapy is given prior to a local treatment such as surgery, and is designed to shrink the primary tumor. It is also given to cancers with a high risk of micrometastatic disease. Adjuvant chemotherapy is given after a local treatment (radiotherapy or surgery). It can be used when there is little evidence of cancer present, but there is risk of recurrence. 7. Maintenance chemotherapy is a repeated lowdose treatment to prolong remission. Salvage chemotherapy is potentially curative high dose ,compination regimens,given in patient with failed or recurrent after many curative regimens . palliative chemotherapy is given without curative intent, but simply to decrease tumor load and increase life expectancy. 8. since these drugs act by inhibiting cell division, the most common side effects are those that occur in areas of the body where cell replication occurs, such as A. the GI mucosa (nausea, vomiting, diarrha), B. the bone marrow (myelosuppression causing leukopnia and other blood dyscrasias), and C. hair follicles (alopecia). D. Most antineoplastics have less effects on those cells that are non-dividing (kidney, heart) and effects on these organs are often the result of damage to portions of the cell other that DNA. 9. Originally derived from mustard gas used in the war, They are so named because of their ability to alkylate many molecules, including proteins, RNA and DNA. This causes "mistakes" in the DNA that may result in mispairing, substitutions, or excision. This leads to a form of programmed cell death called apoptosis. Alkylating agents are non-cell-cycle specific the higher the dose, the more damage to DNA 10. The subtypes of alkylating agents are Nitrogen mustards include mechlorethamine, cyclophosphamide, melphalan and chlorambucil. Alkylsulphonate Busulfan Nitrosoureas include carmustine (BCNU), lomustine (CCNU) Tetrazines includes dacarbazine others include Cisplatin and derivatives include cisplatin,carboplatin and oxaliplatin Non-classical alkylating agents include procarbazine . 11. Two DNA bases that are cross-linked by a nitrogen mustard. Different nitrogen mustards will have different chemical groups (R). The nitrogen mustards most commonly alkylate the N7 nitrogen of guanine (as shown here) but other atoms can be alkylated 12. Meclorethamine Uses -- (MOPP) for Hodgkin's disease and mycosis fungoids. Toxicity -- lacrimation, local damage (irritation, sloughing, necrosis) if extravasation occurs (sodium thiosulphate)Cyclophosphamide Uses -- Lymphoma, chronic leukmia, numerous carcinomas,, breast cancer, multiple myeloma, neuroblastoma and retinoblastoma in children. Toxicity -- pulmonary fibrosis,cardiotoxicity. Other toxicities include a syndrome of inappropriate ADH (SIADH), ridging of nails, and hmorrhagic cystitis. The hmorrhagic cystitis may be diminished by the administration of 2-mercaptoethane sulphonate or MESNA, which donates sulphydryl groups to inactive the drug. 13. Ifosfamide Uses -- Germ cell testicular cancer, sarcomas and salvage therapy in lymphoma( ICE ) Toxicity -- is nephrotoxicity and neurotoxicity deathNephrotoxicity may be diminished by 2-MESNA.(coma,Melphalan Uses -- Multiple myeloma, breast and ovarian cancers Chlorambucil use-- Chronic lymphocytic leukemia, non-Hodkin's lymphoma and macroglobulinmia Toxicity -- Relatively side effect free, Pulmonary toxicity is rare.Alkylsulphonate(Busulfan) Use -- Chronic granulocytic leukmia Toxicity -- pulmonary fibrosis and syndrome .Addison-like 14. Carmustine (BCNU) chloronitrosoureaand Lomustine (CCNU)-- a Uses -- Hodkin's and non-Hodkin lymphoma, brain tumours, multiple myeloma (mini BEAM), malignant melanoma,mycosis fungoides (LOCAL) Toxicity -- Pulmonary fibrosis, Liver and Renal Failure. Triazene (Dacarbazine) Uses -- Malignant melanoma, Hodkin's lymphoma(ABVD), soft tissue cancers, and sarcomas Toxicity -- GI upset, mild to moderate BMS, flu-like syndrome 15. Mechanism of Action -- These agents are bioactivated through substitution of chloride ions for hydroxyl groups. The active moiety then interacts with DNA, forming both inter- and intrastrand links (especially to the DNA base guanine) Uses salvage therapy for lymphoma(DHAP,ESHAP),Ovarian, testicular, bladder, head, neck, and endometrial cancers Toxicity -- Ototoxicity and Neurotoxicity nephrotoxicity (this may be attenuated by hydration and diuresis), and electrolyte disturbances (probably mediated by the liberated chloride ions). Carboplatin Uses salvage therapy for lymphoma(ICE) The same as cisplatin Toxicity -- Fewer toxicities that cisplatin. 16. Mechanism of Action -- Procarbazine methylates DNA, essentially acting in a manner similar to the alkylating agents. Additionally, free radical formation may contribute to the action of procarbazine. Both of these actions will decrease DNA, RNA, and protein synthesis. Use -- Hodkin's lymphoma(MOPP) Toxicity -- neurotoxicity (including behavioural changes), and a disulfiram-like reaction. 17. 1.Folate Antagonists -- Methotrexate Mechanism of Action -- Methotrexate inhibits dihydrofolate reductase Methotrexate is primarily active during the S phase of the cell cycle The toxic effects of methotrexate may be reversed by the administration of leucovorin, which is a fully reduced folate cofactor. Leucovorin "rescue Uses -- Acute lymphocytic leukmia,aggressive lymphoma (MACOP-B) choriocarcinoma, mycosis fungoides, osteogenic sarcoma, and breast. Toxicity -- pneumonitis. Chronic side effects (seen with methotrexate as a immunosuppressant in rheumatoid arthritis or psoriasis) include hepatic fibrosis and cirrhosis. 18. 5-Fluorouracil (5-FU) and Floxuridine -- these drugs are analogues of uridine Mechanism of Action -- Both of these agents are metabolised in vivo to F-UTP and F-dUTP which inhibit RNA and DNA synthesis respectively Uses --Breast, GI, ovarian, cervical, bladder, prostate, and pancreatic cancers and hepatoma. Cytarabine (cytosine arabinoside) -- a cytosine analogue Mechanism of Action -- activated to the nucleotide form to substitute for CTP, inhibiting DNA chain elongation, as previously described. Uses -- Acute granulocytic and lymphocytic leukmias. Toxicity -- DLT = Neurotoxicity (especially in older adults). 19. purine antagonists appear to substitute for guanine or adenosine to decrease/inhibit metabolic reactions that are necessary to form the guanine or adenine that will be incorporated into DNA. 6-Mercaptopurine Uses -- Leukmias Toxicity -- jaundice (33%), and hyperuricmia and hyperuricosuriaAzathioprine -- this drug is a 6-MP derivative that is used for its immunosuppressive effects. The mechanism of action is the same as 6-MP. 20. Fludaribine -- an adenine analogue Mechanism of Action -- Fludaribine inhibits DNA polymerase. Uses -- Chronic lymphocytic leukmia Toxicity --chills, fever, neurotoxicity, and pulmonary toxicity.Cladribine -- an adenine analogue Uses -- Cladribine is the drug of choice of hairy cell leukmiaPentostatin Mechanism of Action -- Pentostatin inhibits adenosine deaminase to increase intracellular levels of adenosine and deoxyadenosine nucleotides. Uses -- hairy cell leukmia and chronic lymphocytic leukmia Toxicity -- neurotoxicity, nephrotoxicity. Also, , rash, and hepatotoxicity. 21. Mechanism of Action -- The vinca alkaloids block cellular mitosis by directly binding to and inhibiting tubulin formation, specifically during metaphase. Vinblastine Uses -- metastatic testicular cancer and lymphoma(ABVD). Toxicity -- SIADH (rare), alopecia, and sloughing/necrosis with extravasation.Vincristine Uses -- Hodkin's and non-Hodkin lymphoma, pediatric leukmias, numerous solid tumours Toxicity -- Neurotoxicity 22. Paclitaxel (Taxol) and Docetaxel Uses -- Ovarian and breast cancers Toxicity -- These agents may also cause bradycardia (early) and silent ventricular tachycardia (late). Epipodophyllotoxins -Mechanism of Action -- The epipodophyllotoxins form a ternary complex with DNA and topoisomerase II, causing double-strand breakage. (Late S,G2 phase) Etoposide Uses -- Testicular, breast, and small-cell lung cancers, salvage therapy non-hodkin lymphoma (ICE,ESHAP,mini BEAM), leukmia, and Kaposi's sarcoma. Teniposide Uses -- Primarily used for refractory acute lymphocytic leukmia in children 23. Anthracycline Antibiotics Mechanism of Action DNA intercalation, preventing DNA and RNA synthesis, single and double stranded breaks (via topoisomerase II). form free radicals (ferrous ion and oxygen are necessary catalysts for their formation) which may directly damage DNA, RNA, or cellular components, accounting at least in part for the cytotoxic effects of the drugs. anthracycline antibiotics form free radicals that responsible for the cardiotoxicity associated with these drugs, through damage to the contractile structures of the myocardium. by the administration of an anti-oxidant (alpha-tocopherol) or an iron chelating agent (dexrazoxane). 24. Daunorubicin (daunomycin, rubidomycin)Doxorubicin (doxomycin) Uses -- Broader spectrum of activity, used in several solid tumours Idarubicin Mitoxantrone -- these are derivatives of the anthracycline antibiotics Uses -- Primarily used for leukmias Toxicity -- cardiotoxicity (manifest early as arrhythmia, late as congestive failure. Mechanism of Action -- The anti-neoplastic effects of mitoxantrone are due to DNA intercalation. It does not exhibit the degree of free radical formation and therefore essentially lacks the cardiotoxic effects of others in the class. 25. Actinomycin D (Dactinomycin) Mechanism of Action -- Dactinomycin intercalates with DNA to prevent DNA transcription by RNA polymerase,Dactinomycin causes strand breaks by decreasing topoisomerase II activity. Uses -- Rhabdomyosarcoma, Wilm's tumour, Choriocarcinoma, testicular cancer, and Kaposi's sarcoma Bleomycin Mechanism of Action -- Bleomycin binds to DNA and generate free radicals. CCS DRUG (G2 PHASE) Uses -- Squamous cell carcinoma, sophageal cancer, testicular and ovarian cancer, and both Hodgkin's(ABVD) and non-Hodgkin lymphoma(MACOP-B). Toxicity -Pulmonary fibrosis, cutaneous toxicity (hyperpigmentation, hyperkeratosis, erythema, ulceration). 26. Mitomycin acts as an alkylating agent to decrease DNA synthesis, increase cross-linking of DNA, and to cause single-strand breakage. Uses -- cervical, colorectal, breast, bladder, and lung cancers. Toxicity -- Hmolytic/uremic syndrome (due to endothelial damage of the red cells and renal epithelium), pulmonary fibrosis and cardiotoxicity. 27. Mechanism of Action -- Most normal cells can synthesis the amino acid asparagine. However, many neoplastic cells lack this capability ,thereby depriving the neoplastic cell of asparagine and thus inhibiting protein synthesis, which leads to cell death by apoptosis. Uses -- leukmias. Toxicity -- Hypersensitivity, However decreases in protein synthesis may lead to insulin deficiency and clotting factor deficiency. Clinical Note -- methotrexate prior to L-asparaginase increases the cytotoxic activity and side effect 28. Mechanism of Action -- Hydroxyurea inhibits the enzyme ribonucleotide reductase, thereby inhibiting the conversion of ribonucleotide to deoxyribonucleotides. This inhibits DNA synthesis. Its actions are specific for the G1 to S phase of the cell cycle.Uses -- Leukmias, polycythemia vera (overproduction of erythrocytes), malignant melanoma. Hydroxyurea is also used in the treatment of sickle cell anmia to decrease hmolysis. This effect is mediated by an increase in the synthesis of hmoglobin F (probably by a separate mechanism, possibly increased expression of the Hgb F gene). 29. Acquired drug-resistant models possess multiple drugresistance mechanisms. These mechanisms include: (a) decreased intracellular concentration of the drug characteristic of overexpression of drug transporters; (b) alterations in the drug target such as point mutations or overexpression of the target; (c) increased detoxification of the drug such as glutathione conjucation; (d) changes in the repair of DNA damage induced by the drug (e) alterations in the cell cycle checkpoint such as p27or p21; (F) changes in the ratio of pro and antiapoptotic BCL-2 family members