Cancer immunotherapy 1661124 223704581 2008-07-05T10:30:08Z DOI bot 6652755 Citation maintenance. Formatted: journal. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. '''Cancer immunotherapy''' is the use of the [[immune system]] to reject [[cancer]]. The main premise is stimulating the patient's immune system to attack the malignant [[tumor]] cells that are responsible for the disease. This can be either through [[immunization]] of the patient, in which case the patient's own immune system is trained to recognize tumor cells as targets to be destroyed, or through the administration of [[Monoclonal antibody#Applications|therapeutic antibodies]] as drugs, in which case the patient's immune system is recruited to destroy tumor cells by the therapeutic antibodies. Since the immune system responds to the environmental factors it encounters on the basis of discrimination between self and non-self, many kinds of tumor [[cell (biology)|cell]]s that arise as a result of the onset of cancer are more or less tolerated by the patient's own immune system since the tumor cells are essentially the patient's own cells that are growing, [[cell division|dividing]] and spreading without proper regulatory control. In spite of this fact, however, many kinds of tumor cells display unusual [[antigen]]s that are either inappropriate for the cell type and/or its environment, or are only normally present during the organisms' development (e.g. [[fetus|fetal]] antigens). Examples of such antigens include the [[glycosphingolipid]] [[GD2]], a [[disialoganglioside]] that is normally only expressed at a significant level on the outer surface membranes of [[neuron]]al cells, where its exposure to the immune system is limited by the [[blood-brain barrier]]. GD2 is expressed on the surfaces of a wide range of tumor cells including [[neuroblastoma]], [[medulloblastoma]]s, [[astrocytoma]]s, [[melanoma]]s, [[small-cell lung cancer]], [[osteosarcoma]]s and other [[soft tissue sarcoma]]s. GD2 is thus a convenient tumor-specific target for immunotherapies. Other kinds of tumor cells display [[cell surface receptor]]s that are rare or absent on the surfaces of healthy cells, and which are responsible for activating cellular [[signal transduction]] pathways that cause the unregulated growth and division of the tumor cell. Examples include [[ErbB2]], a constitutively active cell surface receptor that is produced at abnormally high levels on the surface of [[breast cancer]] tumor cells. ==Monoclonal antibody therapy== {{main|Monoclonal antibody therapy}} [[Antibody|Antibodies]] are a key component of the [[adaptive immune system|adaptive immune response]], playing a central role in both in the recognition of foreign antigens and the stimulation of an immune response to them. It is not surprising therefore, that many immunotherapeutic approaches involve the use of antibodies. The advent of [[monoclonal antibody]] technology has made it possible to raise antibodies against specific antigens such as the unusual antigens that are presented on the surfaces of tumors. A number of therapeutic monoclonal antibodies have been approved for use in humans; approvals mentioned here are by the [[FDA]]. {| class="wikitable" style="margin: 1em auto 1em auto" |+ '''Cancer immunotherapy:Monoclonal antibodies'''<ref name=Waldmann>{{cite journal |author=Waldmann, Thomas A. |title=Immunotherapy: past, present and future |journal=Nature Medicine |year=2003 |volume=9 |issue= |pages= 269&ndash;277 |url=http://www.nature.com/cgi-taf/DynaPage.taf?file=/nm/journal/v9/n3/full/nm0303-269.html&filetype=pdf |doi=10.1038/nm0303-269 }}</ref> ! Antibody||Brand name || Approval date ||Type || Target ||Approved treatment(s) |- | [[Alemtuzumab]] || Campath|| 2001 || humanized || [[CD52]]|| [[Chronic lymphocytic leukemia]] |- | [[Bevacizumab]] || Avastin || 2004 || humanized ||[[vascular endothelial growth factor]]|| [[colorectal cancer]] |- | [[Cetuximab]] || Erbitux || 2004|| chimeric ||[[epidermal growth factor receptor]] ||[[colorectal cancer]] |- | [[Gemtuzumab ozogamicin]] || Mylotarg || 2000|| humanized|| [[CD33]] ||[[acute myelogenous leukemia]] (with [[calicheamicin]]) |- | [[Ibritumomab tiuxetan]] || Zevalin || 2002|| murine || [[CD20]]|| [[non-Hodgkin lymphoma]] (with [[Yttrium|yttrium-90]] or [[Indium|indium-111]]) |- | [[Panitumumab]] || Vectibix || 2006|| human||[[epidermal growth factor receptor]] ||[[colorectal cancer]] |- | [[Rituximab]] || Rituxan, Mabthera || 1997|| chimeric ||[[CD20]] ||[[non-Hodgkin lymphoma]] |- | [[Trastuzumab]] || Herceptin || 1998|| humanized ||[[ErbB2]]|| [[breast cancer]] |- |} === Alemtuzumab=== [[Alemtuzumab]] is an anti-[[CD52]] humanized IgG1 monoclonal antibody indicated for the treatment of [[Chronic lymphocytic leukemia]](CLL), the most frequent form of [[leukaemia]] in Western countries.<ref>Byrd JC, Stilgenbauer S, Flinn IW. [http://www.asheducationbook.org/cgi/content/full/2004/1/163 Chronic Lymphocytic Leukemia.] Hematology (Am Soc Hematol Educ Program) 2004: 163-183. Date retrieved: 26/01/2006.</ref> The function of CD52 is unknown, but it is found on >95% of peripheral blood [[lymphocyte]]s and [[monocyte]]s. Upon binding to CD52, alemtuzumab initiates its cytotoxic effect by [[complement system|complement]] fixation and antibody-dependent cell-mediated cytotoxicity mechanisms. Alemtuzumab therapy is also indicated for T-prolymphocytic leukaemia (TPPL), for which no standard treatment exists. This is a highly aggressive tumour, with a median survival of 7.5 months.<ref>Keating MJ, Cazin B, Coutre S, et al. Campath-1H treatment of T-cell prolymphocytic leukemia in patients for whom at least one prior chemotherapy regimen has failed. J Clin Oncol 2002; 20: 205-213.</ref> ===Bevacizumab === [[Bevacizumab]] is a humanized IgG1 monoclonal antibody which binds to and [[steric]]ally interferes with the [[vascular endothelial growth factor]]-A (VEGF-A), preventing [[Receptor (biochemistry)|receptor]] activation. A marked increase in [[VEGF]] expression is thought to play a role in [[tumor]] [[angiogenesis]]. Bevacizumab is indicated for [[colon cancer]]; but has been applied to numerous other cancers in small scale studies, especially [[renal cell carcinoma]]. Results obtained showed that bevacizumab increased the duration of survival, progression-free survival, the rate of response and the duration of response in a statistically relevant manner.<ref>Hurwitz H, Fehrenbacher L, Novotny W, et al. Bevacizumab plus irinotecan, fluorouracil, and leucovorin for metastatic colorectal cancer. N Engl J Med 2004; 350: 2335&ndash;2342.</ref> === Cetuximab === [[Cetuximab]] is a chimeric IgG1 monoclonal antibody which targets the extracellular domain of the [[epidermal growth factor receptor]] (EGFR). It functions by competitively inhibiting [[ligand]] binding, thereby preventing EGFR activation, and is indicated for the treatment of [[colorectal cancer]]. Studies have also been carried out on numerous other malignancies, especially [[non-small cell lung cancer]] and [[head and neck cancer]]. As a single agent, cetuximab showed a response rate of 10.8% in patients with EGFR overexpressed metastatic colon cancer.<ref name=Waldmann/> Other anti-EGFR monoclonal antibodies in development include: [[ABX-EGF]], [[hR3]], and [[EMD 72000]]. Although they hold significant promise for the future, as of yet none of the agents are currently beyond phase I [[clinical trial]]s. === Gemtuzumab ozogamicin === [[Gemtuzumab ozogamicin]] is an “immuno-conjugate” of an anti-[[CD33]] antibody chemically linked to [[calicheamicin]], a cytotoxic agent. It is indicated for the treatment of [[acute myeloid leukaemia]] (AML). The patient group most likely to benefit from gemtuzumab is young adults, and trials have reported high complete responses (85%), when combined with intensive chemotherapy. There are minimal side-effects associated with Gemtuzumab therapy.<ref>De Angelo D, Stone R, Durant S, et al. Gemtuzumab ozogamicin (Mylotarg) in combination with induction chemotherapy for the treatment of patients with de novo acute myeloid leukemia: Two age-specific phase 2 trials. Blood 2003; 102: 100a [abstract].</ref> === Rituximab === [[Rituximab]] is a chimeric monoclonal antibody specific for [[CD20]]. CD20 is widely expressed on B-cells. Although the function of CD20 is relatively unknown it has been suggested that CD20 could play a role in [[calcium]] influx across [[plasma membrane]], maintaining intracellular calcium concentration and allowing for the activation of [[B cells]].<ref name=Janeway>{{cite book | last = Janeway | first = Charles | authorlink = Charles Janeway | coauthors = Paul Travers, Mark Walport, and Mark Shlomchik | title = Immunobiology; Fifth Edition | publisher = Garland Science | date = 2001 | location = New York and London| pages = | url = http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowTOC&rid=imm.TOC&depth=10| doi = | id = ISBN 0-8153-4101-6}}.</ref> The exact mode of action of rituximab is also unclear, but it has been found to have a general regulatory effect on the [[cell cycle]] and on immune-receptor expression.<ref name=Waldmann/> Experiments involving [[primate]]s showed that treatment with anti-CD20 reduced peripheral B-cells by 98%, and peripheral [[lymph node]] and [[bone marrow]] B-cells by up to 95%.<ref>Reff ME, Carner K, Chambers KS, et al. Depletion of B cells ''in vivo'' by a chimeric mouse human monoclonal antibody to CD20. Blood 1994; 83: 435-445.</ref> === Trastuzumab === [[Trastuzumab]] is a monoclonal IgG1 humanized antibody specific for the [[epidermal growth factor receptor]] 2 protein ([[HER2]]). It received FDA-approval in 1998, and is clinically used for the treatment of [[breast cancer]]. The use of Trastuzumab is restricted to patients whose tumours over-express HER-2, as assessed by [[immunohistochemistry]] (IHC) and either chromogenic or [[fluorescence|Fluorescent]] [[in situ]] [[nucleic acid hybridization|hybridisation]] ([[Fluorescent in situ hybridization|FISH]]), as well as numerous [[PCR]]-based methodologies. HER-2 is a member of the epidermal growth factor receptor (EGFR) family of transmembrane [[tyrosine kinases]], and is normally involved in regulation of [[cell proliferation]] and [[differentiation]].<ref>Jones FE, Stern DF. Expression of dominant-negative ErbB2 in the mammary gland of transgenic mice reveals a role in lobuloalveolar development. Oncogene 1999; 18: 3481-3490.</ref> Amplification or overexpression of HER-2 is present in 25-30% of breast carcinomas and has been associated with aggressive tumour phenotype, poor [[prognosis]], non-responsiveness to [[hormonal therapy]] and reduced sensitivity to conventional chemotherapeutic agents.<ref>Slamon DJ, Godolphin W, Jones LA, et al. Studies of the HER-2/neu proto oncogene in human breast and ovarian cancer. Science 1989; 244: 707-712.</ref> == Radioimmunotherapy == [[Radioimmunotherapy]] involves the use of [[radioactive]]ly conjugated murine antibodies against cellular antigens. Most research currently involved their application to [[lymphomas]], as these are highly radio-sensitive malignancies. To limit radiation exposure, murine antibodies were especially chosen, as their high immunogenicity promotes rapid clearance from the body. ===Ibritumomab tiuxetan=== [[Ibritumomab]] is a murine antibody chemically linked to [[tiuxetan]], which chelates [[Yttrium]]-90. <sup>90</sup>Y is a [[beta radiation|beta]] radiator, has a [[half-life]] of 64 h and a tissue penetration of 1-5 millimetres. Its use has been investigated, primarily in the treatment of [[follicular lymphoma]].<ref>Shipley DL, Spigel DR, Carrell DL, Dannaher C, Greco FA, Hainsworth JD. Phase II trial of rituximab and short duration chemotherapy followed by 90Y-ibritumomab tiuxetan as first-line treatment for patients with follicular lymphoma: A Minnie Pearl Cancer Research Network phase II trial. J Clin Oncol 2004; 22: 6519 [abstract].</ref> ===Tositumomab=== [[Tositumomab]] is a murine IgG2a anti-[[CD20]] antibody and is covalently bound to [[Iodine]] 131. <sup>131</sup>I emits both [[beta radiation|beta]] and [[gamma radiation]], and is broken down rapidly in the body.<ref>Rao AV, Akabani G, Rizzieri DA. Radioimmunotherapy for Non-Hodgkin’s Lymphoma. Clin Med Res 2005; 3: 157-165.</ref> Clinical trials have established the efficacy of tositumomab in patients with [[relapse]]d [[follicular lymphoma]].<ref>Kaminski MS, Tuck M, Estes J, et al. 131I-tositumomab therapy as initial treatment for follicular lymphoma. N Engl J Med 2005; 352: 441-449.</ref> ==Advances in immunotherapy== The development and testing of second generation immunotherapies are already under way. While antibodies targeted to disease-causing antigens can be effective under certain circumstances, in many cases, their efficacy may be limited by other factors. In the case of cancer tumors, the microenvironment is [[immunosuppression|immunosuppressive]], allowing even those tumors that present unusual antigens to survive and flourish in spite of the immune response generated by the cancer patient, against his or her own tumor tissue. Certain members of a group of molecules known as [[cytokine]]s, such as [[Interleukin-2]] also play a key role in modulating the immune response, and have been tried in conjunction with antibodies in order to generate an even more devastating immune response against the tumor. While the therapeutic administration of such cytokines may cause systemic inflammation, resulting in serious [[side effect]]s and [[toxicity]], a new generation of [[chimera (protein)|chimeric]] molecules consisting of an immune-stimulatory cytokine attached to an antibody that targets the cytokine's activity to a specific environment such as a tumor, are able to generate a very effective yet localized immune response against the tumor tissue, destroying the cancer-causing cells without the unwanted side-effects. A different type of chimeric molecule is an [[artificial T cell receptor]]. The targeted delivery of cytokines by anti-tumor antibodies is one example of using antibodies to delivery payloads rather than simply relying on the antibody to trigger an immune response against the target cell. Another strategy is to deliver a lethal radioactive dose directly to the target cell, which has been utilized in the case of the [[Ibritumomab tiuxetan|Zevalin]] therapeutic. A third strategy is to deliver a lethal chemical dose to the target, as used in the [[Gemtuzumab ozogamicin|Mylotarg]] therapeutic. Engineering the antibody-payload pair in such a way that they separate after entry into a cell by [[endocytosis]] can potentially increase the efficacy of the payload. One strategy to accomplish this is the use of a [[Disulfide bond|disulfide linkage]] which could be severed by the [[reducing]] conditions in the cellular interior. However, recent evidence suggests that the actual intracellular trafficking of the antibody-payload after endocytosis is such to make this strategy not generally applicable. Other potentially useful linkage types include [[hydrazone]] and [[Peptide bond|peptide]] linkages.<ref>{{cite journal |author=Austin C.D. ''et al.'' |title=Oxidizing potential of endosomes and lysosomes limits intracellular cleavage of disulfide-based antibody-drug conjugates |journal=Proc Natl Acad Sci U S a |year=2005 |volume=102 |issue=50 |pages= 17987&ndash;17992 |url=http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=16322102 |doi=10.1073/pnas.0509035102 |pmid=16322102 }}</ref> ==Latest Research== In June 2008, it was announced that [[US]] doctors from the Clinical Research Division at [[Fred Hutchinson Cancer Research Center]] in [[Seattle]] have for the first time successfully treated a [[skin cancer]] patient by using [[immune cells]] [[cloned]] from his own [[immune system]] which were then re-injected into him. The patient, who was suffering from advanced skin cancer, was free from tumours within eight weeks of being injected with billions of his own immune cells in the first case of its kind. Experts say that this case could mark a landmark in the treatment of cancer in general. Larger trials are now under way. [http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/06/18/scicanc118.xml] [http://www.breitbart.com/article.php?id=080618212711.38ht6zq0&show_article=1] ==Topical immunotherapy== Dermatologists use new creams and injections in the management of benign and malignant skin tumors. [[Topical]] immunotherapy utilizes an immune enhancement cream ([[imiquimod]]) which is an [[interferon]] producer causing the patient's own [[killer T cell]]s to destroy [[wart]]s, [[actinic keratoses]], [[basal cell carcinoma]], [[squamous cell carcinoma]], [[cutaneous T cell lymphoma]], and [[Superficial spreading melanoma]]. Injection immunotherapy uses [[mumps]], [[candida]] or [[trichophytin]] antigen injections to treat warts ([[HPV]] induced tumors). ==See also== * [[5T4|Antigen 5T4]] * [[Cancer vaccine]] * [[Immunotherapy]] * [[Coley's Toxins]] * [[Tumor antigen]] ==External links== *[http://www.c-imt.org Association for Immunotherapy of Cancer] *[http://www.isbtc.org International Society for Biological Therapy of Cancer] * [http://www.sabin.org/programs/cvc/index.html Cancer Vaccine Consortium] ==References== {{Reflist|2}} {{Tumors}} {{Chemotherapeutic agents}} [[Category:Immune system]] [[Category:Cancer treatments]] [[lt:Imunoterapija]] [[sl:Biološka zdravila]]