Targeted therapy or molecularly targeted therapy is one of the major modalities of medical treatment (pharmacotherapy) for cancer, others being hormonal therapy and cytotoxic chemotherapy. As a form of molecular medicine, targeted therapy blocks the growth of cancer cells by interfering with specific targeted molecules needed for carcinogenesis and tumor growth, rather than by simply interfering with all rapidly dividing cells. Because most agents for targeted therapy are biopharmaceuticals, the term biologic therapy is sometimes synonymous with targeted therapy when used in the context of cancer therapy. However, the modalities can be combined; antibody-drug conjugates combine biologic and cytotoxic mechanisms into one targeted therapy.
The nomenclature of monoclonal antibodies is a naming scheme for assigning generic, or nonproprietary, names to monoclonal antibodies. An antibody is a protein that is produced in B cells and used by the immune system of humans and other vertebrate animals to identify a specific foreign object like a bacterium or a virus. Monoclonal antibodies are those that were produced in identical cells, often artificially, and so share the same target object. They have a wide range of applications including medical uses.
Monoclonal antibody therapy is a form of immunotherapy that uses monoclonal antibodies (mAbs) to bind monospecifically to certain cells or proteins. The objective is that this treatment will stimulate the patient's immune system to attack those cells. Alternatively, in radioimmunotherapy a radioactive dose localizes a target cell line, delivering lethal chemical doses. Antibodies have been used to bind to molecules involved in T-cell regulation to remove inhibitory pathways that block T-cell responses. This is known as immune checkpoint therapy.
Tremelimumab, sold under the brand name Imjudo, is a fully human monoclonal antibody used for the treatment of hepatocellular carcinoma. Tremelimumab is designed to attach to and block CTLA-4, a protein that controls the activity of T cells, which are part of the immune system.
Mertansine, also called DM1, is a thiol-containing maytansinoid that for therapeutic purposes is attached to a monoclonal antibody through reaction of the thiol group with a linker structure to create an antibody-drug conjugate (ADC).
Monomethyl auristatin E (MMAE) is a synthetic antineoplastic agent. Because of its toxicity, it cannot be used as a drug itself; instead, it is linked to a monoclonal antibody (MAB) which directs it to the cancer cells. In International Nonproprietary Names for MMAE-MAB-conjugates, the name vedotin refers to MMAE plus its linking structure to the antibody. It is a potent antimitotic drug derived from peptides occurring in marine shell-less mollusc Dolabella auricularia called dolastatins which show potent activity in preclinical studies, both in vitro and in vivo, against a range of lymphomas, leukemia and solid tumors. These drugs show potency of up to 200 times that of vinblastine, another antimitotic drug used for Hodgkin lymphoma as well as other types of cancer.
Glembatumumab vedotin is an antibody-drug conjugate (ADC) that targets cancer cells expressing transmembrane glycoprotein NMB (GPNMB).
Antibody-drug conjugates or ADCs are a class of biopharmaceutical drugs designed as a targeted therapy for treating cancer. Unlike chemotherapy, ADCs are intended to target and kill tumor cells while sparing healthy cells. As of 2019, some 56 pharmaceutical companies were developing ADCs.
Trastuzumab emtansine, sold under the brand name Kadcyla, is an antibody-drug conjugate consisting of the humanized monoclonal antibody trastuzumab (Herceptin) covalently linked to the cytotoxic agent DM1. Trastuzumab alone stops growth of cancer cells by binding to the HER2 receptor, whereas trastuzumab emtansine undergoes receptor-mediated internalization into cells, is catabolized in lysosomes where DM1-containing catabolites are released and subsequently bind tubulin to cause mitotic arrest and cell death. Trastuzumab binding to HER2 prevents homodimerization or heterodimerization (HER2/HER3) of the receptor, ultimately inhibiting the activation of MAPK and PI3K/AKT cellular signalling pathways. Because the monoclonal antibody targets HER2, and HER2 is only over-expressed in cancer cells, the conjugate delivers the cytotoxic agent DM1 specifically to tumor cells. The conjugate is abbreviated T-DM1.
Vorsetuzumab mafodotin (SGN-75) is an antibody-drug conjugate (ADC) directed to the protein CD70 designed for the treatment of cancer. It is a humanized monoclonal antibody, vorsetuzumab, conjugated with noncleavable monomethyl auristatin F (MMAF), a cytotoxic agent.
Seagen Inc. is an American biotechnology company focused on developing and commercializing innovative, empowered monoclonal antibody-based therapies for the treatment of cancer. The company, headquartered in Bothell, Washington, is the industry leader in antibody-drug conjugates or ADCs, a technology designed to harness the targeting ability of monoclonal antibodies to deliver cell-killing agents directly to cancer cells. Antibody-drug conjugates are intended to spare non-targeted cells and thus reduce many of the toxic effects of traditional chemotherapy, while potentially enhancing antitumor activity.
ImmunoGen, Inc. is a biotechnology company focused on the development of antibody-drug conjugate (ADC) therapeutics for the treatment of cancer. ImmunoGen was founded in 1981 and is headquartered in Waltham, Massachusetts.
Varlilumab is a monoclonal antibody designed for immunotherapy for solid tumors and hematologic malignancies. It is an anti-CD27 antibody and helps activate T-cells.
Sofituzumab vedotin is a monoclonal antibody designed for the treatment of ovarian cancer.
Denintuzumab mafodotin is a humanized monoclonal antibody-drug conjugate designed for the treatment of CD19-positive acute lymphoblastic leukemia and B-cell non-Hodgkin lymphoma. It consists of an anti-CD19 mAb linked to monomethyl auristatin F (MMAF), a cytotoxic agent. This drug was developed by Seattle Genetics.
Depatuxizumab mafodotin is an antibody-drug conjugate designed for the treatment of cancer. It is composed of an EGFR IGg1 monoclonal antibody (depatuxizumab) conjugated to the tubulin inhibitor monomethyl auristatin F via a stable maleimidocaproyl link.
Loncastuximab tesirine, sold under the brand name Zynlonta, is a monoclonal antibody conjugate medication used to treat large B-cell lymphoma and high-grade B-cell lymphoma. It is an antibody-drug conjugate (ADC) composed of a humanized antibody targeting the protein CD19.
Dostarlimab, sold under the brand name Jemperli, is a monoclonal antibody used as an anti-cancer medication for the treatment of endometrial cancer. Dostarlimab is a programmed death receptor-1 (PD-1)–blocking monoclonal antibody.
Belantamab mafodotin, sold under the brand name Blenrep, is a medication for the treatment of relapsed and refractory multiple myeloma.
Tisotumab vedotin, sold under the brand name Tivdak, is an antibody-drug conjugate used to treat cervical cancer. It is a combination of tisotumab, a monoclonal antibody against tissue factor, and monomethyl auristatin E (MMAE), a potent inhibitor of cell division. It is administered by infusion into a vein.
