Monoclonal antibody therapy is a form of
immunotherapy
Immunotherapy or biological therapy is the treatment of disease by activating or suppressing the immune system. Immunotherapies designed to elicit or amplify an immune response are classified as ''activation immunotherapies,'' while immunotherap ...
that uses
monoclonal antibodies (mAbs) to bind
monospecifically to certain
cells or
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
s. The objective is that this treatment will stimulate the patient's
immune system
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...
to attack those cells. Alternatively, in
radioimmunotherapy
Radioimmunotherapy (RIT) uses an antibody labeled with a radionuclide to deliver cytotoxic radiation to a target cell. It is a form of unsealed source radiotherapy. In cancer therapy, an antibody with specificity for a tumor-associated antigen i ...
a radioactive dose localizes a target cell line, delivering lethal chemical doses.
Antibodies have been used to bind to molecules involved in
T-cell
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell r ...
regulation to remove inhibitory pathways that block T-cell responses. This is known as immune
checkpoint therapy.
It is possible to create a mAb that is specific to almost any
extracellular
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...
/cell surface target. Research and development is underway to create antibodies for diseases (such as
rheumatoid arthritis
Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...
,
multiple sclerosis
Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...
,
Alzheimer's disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...
,
Ebola
Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever in humans and other primates, caused by ebolaviruses. Symptoms typically start anywhere between two days and three weeks after becom ...
and different types of
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
s).
Antibody structure and function
Immunoglobulin
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
G (
IgG
Immunoglobulin G (Ig G) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG ...
) antibodies are large
heterodimeric molecules, approximately 150
kDa
The dalton or unified atomic mass unit (symbols: Da or u) is a non-SI unit of mass widely used in physics and chemistry. It is defined as of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at re ...
and are composed of two kinds of
polypeptide chain, called the heavy (~50kDa) and the light chain (~25kDa). The two types of light chains are kappa (κ) and lambda (λ). By cleavage with enzyme
papain
Papain, also known as papaya proteinase I, is a cysteine protease () enzyme present in papaya (''Carica papaya'') and mountain papaya (''Vasconcellea cundinamarcensis''). It is the namesake member of the papain-like protease family.
It has wide ...
, the
Fab (''fragment-antigen binding'') part can be separated from the
Fc (''fragment constant'') part of the molecule. The Fab fragments contain the variable domains, which consist of three antibody
hypervariable amino acid domains responsible for the antibody specificity embedded into constant regions. The four known IgG subclasses are involved in
antibody-dependent cellular cytotoxicity
Antibody-dependent cellular cytotoxicity (ADCC), also referred to as antibody-dependent cell-mediated cytotoxicity, is a mechanism of cell-mediated immune defense whereby an effector cell of the immune system actively lyses a target cell, whose ...
.
Antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
are a key component of the
adaptive immune response, playing a central role in both in the recognition of foreign antigens and the stimulation of an immune response to them. The advent of
monoclonal antibody
A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell.
Monoclonal antibodies ca ...
technology has made it possible to raise antibodies against specific antigens presented on the surfaces of tumors.
Monoclonal antibodies can be acquired in the immune system via
passive immunity Passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially, when hi ...
or
active immunity. The advantage of active monoclonal antibody therapy is the fact that the immune system will produce antibodies long-term, with only a short-term drug administration to induce this response. However, the immune response to certain antigens may be inadequate, especially in the elderly. Additionally, adverse reactions from these antibodies may occur because of long-lasting response to antigens.
Passive monoclonal antibody therapy can ensure consistent antibody concentration, and can control for adverse reactions by stopping administration. However, the repeated administration and consequent higher cost for this therapy are major disadvantages.
Monoclonal antibody therapy may prove to be beneficial for
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
,
autoimmune diseases, and neurological disorders that result in the degeneration of body cells, such as
Alzheimer's disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...
. Monoclonal antibody therapy can aid the immune system because the innate immune system responds to the environmental factors it encounters by discriminating against foreign cells from cells of the body. Therefore, tumor
cell
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
s that are proliferating at high rates, or body cells that are dying which subsequently cause physiological problems are generally not specifically targeted by the immune system, since tumor cells are the patient's own cells. Tumor cells, however are highly abnormal, and many display unusual
antigen
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...
s. Some such
tumor antigen
Tumor antigen is an antigenic substance produced in tumor cells, i.e., it triggers an immune response in the host. Tumor antigens are useful tumor markers in identifying tumor cells with diagnostic tests and are potential candidates for use in c ...
s are inappropriate for the cell type or its environment. Monoclonal antibodies can target tumor cells or abnormal cells in the body that are recognized as body cells, but are debilitating to one's health.
History
Immunotherapy
Immunotherapy or biological therapy is the treatment of disease by activating or suppressing the immune system. Immunotherapies designed to elicit or amplify an immune response are classified as ''activation immunotherapies,'' while immunotherap ...
developed in the 1970s following the discovery of the structure of
antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
and the development of
hybridoma
Hybridoma technology is a method for producing large numbers of identical antibodies (also called monoclonal antibodies). This process starts by injecting a mouse (or other mammal) with an antigen that provokes an immune response. A type of white ...
technology, which provided the first reliable source of
monoclonal antibodies.
These advances allowed for the specific targeting of tumors both
in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...
and
in vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...
. Initial research on
malignant
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
neoplasms
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
found mAb therapy of limited and generally short-lived success with blood malignancies. Treatment also had to be tailored to each individual patient, which was impracticable in routine clinical settings.
Four major antibody types that have been developed are
murine
The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. Members of this subfamily are called murines. In terms of species richness, this subfamily is larger than all mammal families ex ...
,
chimeric,
humanised and human. Antibodies of each type are distinguished by suffixes on their name.
Murine
Initial therapeutic antibodies were murine
analogues (suffix ''-omab''). These antibodies have: a short half-life in vivo (due to
immune complex
An immune complex, sometimes called an antigen-antibody complex or antigen-bound antibody, is a molecule formed from the binding of multiple antigens to antibodies. The bound antigen and antibody act as a unitary object, effectively an antigen o ...
formation), limited penetration into tumour sites and inadequately recruit host effector functions.
Chimeric and humanized antibodies have generally replaced them in therapeutic antibody applications.
Understanding of
proteomics has proven essential in identifying novel tumour targets.
Initially, murine antibodies were obtained by hybridoma technology, for which Jerne, Köhler and Milstein received a Nobel prize. However the dissimilarity between murine and human immune systems led to the clinical failure of these antibodies, except in some specific circumstances. Major problems associated with murine antibodies included reduced stimulation of
cytotoxic
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa'').
Cell physiology
Treating cells ...
ity and the formation of complexes after repeated administration, which resulted in mild
allergic reaction
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...
s and sometimes
anaphylactic shock.
Hybridoma
Hybridoma technology is a method for producing large numbers of identical antibodies (also called monoclonal antibodies). This process starts by injecting a mouse (or other mammal) with an antigen that provokes an immune response. A type of white ...
technology has been replaced by
recombinant DNA technology
Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms. The use of the word ''cloning'' refers to the fact that the metho ...
,
transgenic
A transgene is a gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another. The introduction of a transgene, in a process known as transgenesis, has the potential to change the ...
mice and
phage display.
Chimeric and humanized
To reduce murine antibody
immunogenicity
Immunogenicity is the ability of a foreign substance, such as an antigen, to provoke an immune response in the body of a human or other animal. It may be wanted or unwanted:
* Wanted immunogenicity typically relates to vaccines, where the injectio ...
(attacks by the immune system against the antibody), murine molecules were engineered to remove immunogenic content and to increase immunologic efficiency.
This was initially achieved by the production of chimeric (suffix ''-ximab)'' and humanized antibodies (suffix ''-zumab''). Chimeric antibodies are composed of murine variable regions fused onto human constant regions. Taking human gene sequences from the kappa light chain and the IgG1 heavy chain results in antibodies that are approximately 65% human. This reduces immunogenicity, and thus increases
serum half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...
.
Humanised antibodies are produced by grafting murine hypervariable regions on amino acid domains into human antibodies. This results in a molecule of approximately 95% human origin. Humanised antibodies bind antigen much more weakly than the parent murine monoclonal antibody, with reported decreases in affinity of up to several hundredfold. Increases in antibody-antigen binding strength have been achieved by introducing
mutations
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
into the
complementarity determining regions
Complementarity-determining regions (CDRs) are part of the variable chains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules bind to their specific antigen. A set of CDRs co ...
(CDR), using techniques such as chain-shuffling, randomization of complementarity-determining regions and antibodies with mutations within the variable regions induced by error-prone
PCR,
E. coli mutator strains and
site-specific mutagenesis.
Human monoclonal antibodies
Human monoclonal antibodies (suffix ''-umab'') are produced using
transgenic
A transgene is a gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another. The introduction of a transgene, in a process known as transgenesis, has the potential to change the ...
mice or
phage display libraries by transferring human
immunoglobulin
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
genes into the murine genome and vaccinating the transgenic mouse against the desired antigen, leading to the production of appropriate monoclonal antibodies.
Murine antibodies in vitro are thereby transformed into fully human antibodies.
The heavy and light chains of human IgG proteins are expressed in structural polymorphic (allotypic) forms. Human IgG
allotype is one of the many factors that can contribute to immunogenicity.
Targeted conditions
Cancer
Anti-cancer monoclonal antibodies can be targeted against malignant cells by several mechanisms. Ramucirumab is a recombinant human monoclonal antibody and is used in the treatment of advanced malignancies. In childhood lymphoma, phase I and II studies have found a positive effect of using antibody therapy.
Autoimmune diseases
Monoclonal antibodies used for
autoimmune disease
An autoimmune disease is a condition arising from an abnormal immune response to a functioning body part. At least 80 types of autoimmune diseases have been identified, with some evidence suggesting that there may be more than 100 types. Nearly a ...
s include
infliximab
Infliximab, a chimeric monoclonal antibody, sold under the brand name Remicade among others, is a medication used to treat a number of autoimmune diseases. This includes Crohn's disease, ulcerative colitis, rheumatoid arthritis, ankylosing spon ...
and
adalimumab
Adalimumab, sold under the brand name Humira, among others, is a monoclonal antibody used to treat rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, ulcerative colitis, plaque psoriasis, hidradenitis suppurati ...
, which are effective in
rheumatoid arthritis
Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...
,
Crohn's disease and
ulcerative colitis
Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary symptoms of active disease are abdominal pain and diarrhea mixed with blood (hematochezia). Weight loss, fever, and a ...
by their ability to bind to and inhibit
TNF-α
Tumor necrosis factor (TNF, cachexin, or cachectin; formerly known as tumor necrosis factor alpha or TNF-α) is an adipokine and a cytokine. TNF is a member of the TNF superfamily, which consists of various transmembrane proteins with a homolog ...
.
Basiliximab
Basiliximab (trade name Simulect) is a chimeric mouse-human monoclonal antibody to the α chain (CD25) of the IL-2 receptor of T cells. It is used to prevent rejection in organ transplantation, especially in kidney transplants.
Uses
Basiliximab ...
and
daclizumab
Daclizumab (trade name Zinbryta) is a therapeutic humanized monoclonal antibody which was used for the treatment of adults with relapsing forms of multiple sclerosis (MS). Daclizumab works by binding to CD25, the alpha subunit of the IL-2 receptor ...
inhibit
IL-2
The Ilyushin Il-2 (Russian: Илью́шин Ил-2) is a ground-attack plane that was produced by the Soviet Union in large numbers during the Second World War. The word ''shturmovík'' ( Cyrillic: штурмовик), the generic Russian term ...
on activated
T cells
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell re ...
and thereby help preventing acute
rejection of kidney transplants.
[ ]Omalizumab
Omalizumab, sold under the brand name Xolair, is a medication used to treat asthma, nasal polyps, and urticaria (hives).
Omalizumab is a recombinant DNA-derived humanized IgG1k monoclonal antibody that specifically binds to free human immunoglo ...
inhibits human immunoglobulin E
Immunoglobulin E (IgE) is a type of antibody (or immunoglobulin (Ig) " isotype") that has been found only in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains (ε chain) and two light chains, with the ...
(IgE) and is useful in moderate-to-severe allergic asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...
.
Alzheimer's disease
Alzheimer's disease (AD) is a multi-faceted, age-dependent, progressive neurodegenerative disorder, and is a major cause of dementia. According to the Amyloid hypothesis, the accumulation of extracellular amyloid betapeptides (Aβ) into plaques via oligomerization leads to hallmark symptomatic conditions of AD through synaptic dysfunction and neurodegeneration. Immunotherapy via exogenous monoclonal antibody (mAb) administration has been known to treat various central nervous disorders, such as AD, by inhibiting Aβ-oligomerization thereby preventing neurotoxicity. However, mAbs are large for passive protein channels and are therefore inefficient due to the blood–brain barrier
The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that prevents solutes in the circulating blood from ''non-selectively'' crossing into the extracellular fluid of ...
preventing mAb passage into the brain. However, the Peripheral Sink hypothesis proposes a mechanism where mAbs may not need to cross the blood–brain barrier. Therefore, many research studies are being conducted from failed attempts to treat AD in the past.
However, anti-Aβ vaccines can promote antibody-mediated clearance of Aβ plaques in transgenic mice models with amyloid precursor proteins (APP), and can reduce cognitive impairments. Vaccines
A vaccine is a biological preparation that provides active acquired immunity
The adaptive immune system, also known as the acquired immune system, is a subsystem of the immune system that is composed of specialized, systemic cells and pro ...
can stimulate the immune system to produce its own antibodies, in this case by introducing Aβ into transgenic animal models, known as active immunization
Active immunization is the induction of immunity after exposure to an antigen. Antibodies are created by the recipient and may be stored permanently.
Active immunization can occur naturally when microbes or other antigen are received by a person ...
. They can also introduce antibodies into animal models, known as passive immunization Passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially, when ...
. In mice expressing APP, both active and passive immunization of anti-Aβ antibodies has been shown to be effective in clearing plaques, and can improve cognitive function. Currently, there are no approved monoclonal antibody therapies for Alzheimer's disease, but several clinical trials using passive and active immunization approaches by development of certain drugs approved by the FDA are currently underway, and are expected to yield results in a couple of years. The implementation of these drugs is during the onset of AD. Other research and drug development for early intervention and AD prevention is ongoing. Various drugs that are under research to treat AD include Bapineuzumab, Solanezumab, Gautenerumab, and BAN2401.
Bapineuzumab
Bapineuzumab, a humanized anti-Aβ mAb, is directed against the N-terminus of Aβ. Phase II clinical trials of Bapineuzumab in mild to moderate AD patients resulted in reduced Aβ concentration in the brain. However, in patients with increased apolipoprotein
Apolipoproteins are proteins that bind lipids (oil-soluble substances such as fats, cholesterol and fat soluble vitamins) to form lipoproteins. They transport lipids in blood, cerebrospinal fluid and lymph.
The lipid components of lipoproteins ...
(APOE) e4 carriers, Bapineuzumab treatment is also accompanied by vasogenic edema
Cerebral edema is excess accumulation of fluid ( edema) in the intracellular or extracellular spaces of the brain. This typically causes impaired nerve function, increased pressure within the skull, and can eventually lead to direct compressi ...
, a cytotoxic condition where the blood brain barrier has been disrupted thereby affecting white matter from excess accumulation of fluid from capillaries in intracellular and extracellular spaces of the brain.
In Phase III clinical trials, Bapineuzumab treatment is associated with reduced rate of accumulation of Aβ in the brain in APOE e4 patients, and no significant reduction of Aβ concentration in APOE e4 patients and non-APOE e4 patients. Therefore, Aβ plaque concentration was not reduced, and there is no significant clinical benefits in cognitive functioning. Bapineuzumab was discontinued after failing in Phase III clinical trial.
Solanezumab
Solanezumab, an anti-Aβ mAb, targets the N-terminus of Aβ. In Phase I and Phase II of clinical trials, Solanezumab treatment resulted in cerebrospinal fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...
elevation of Aβ, thereby showing a reduced concentration of Aβ plaques. Additionally, there are no associated adverse side effects. Phase III clinical trials of Solanezumab brought about significant reduction in cognitive impairment in patients with mild AD, but not in patients with severe AD. However, Aβ concentration did not significantly change, along with other AD biomarkers, including phospho-tau expression, and hippocampal volume. Phase III clinical trials are currently ongoing.
BAN2401
BAN2401, is a humanized mAb that selectively targets toxic soluble Aβ protofibrils, and the therapy is currently undergoing a phase 3 clinical trial which is expected to be completed in 2022.
Preventive trials
Failure of several drugs in Phase III clinical trials has led to AD prevention and early intervention for onset AD treatment endeavours. Passive anti-Aβ mAb treatment can be used for preventive attempts to modify AD progression before it causes extensive brain damage and symptoms. Trials using mAb treatment for patients positive for genetic risk factors, and elderly patients positive for indicators of AD are underway. This includes anti-AB treatment in Asymptomatic Alzheimer's Disease (A4), the Alzheimer's Prevention Initiative (API), and DIAN-TU.
The A4 study on older individuals who are positive for indicators of AD but are negative for genetic risk factors will test Solanezumab in Phase III Clinical Trials, as a follow up of previous Solanezumab studies.
DIAN-TU, launched in December 2012, focuses on young patients positive for genetic mutations that are risks for AD. This study uses Solanezumab and Gautenerumab. Gautenerumab, the first fully human MAB that preferentially interacts with oligomerized Aβ plaques in the brain, caused significant reduction in Aβ concentration in Phase I clinical trials, preventing plaque formation and concentration without altering plasma concentration of the brain. Phase II and III clinical trials are currently being conducted.
Therapy types
Radioimmunotherapy
Radioimmunotherapy
Radioimmunotherapy (RIT) uses an antibody labeled with a radionuclide to deliver cytotoxic radiation to a target cell. It is a form of unsealed source radiotherapy. In cancer therapy, an antibody with specificity for a tumor-associated antigen i ...
(RIT) involves the use of radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...
ly-conjugated murine antibodies against cellular antigens. Most research involves their application to lymphomas
Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enla ...
, as these are highly radio-sensitive malignancies. To limit radiation exposure, murine antibodies were chosen, as their high immunogenicity promotes rapid tumor clearance. Tositumomab
Tositumomab is a murine monoclonal antibody which targets the CD20 antigen produced in mammalian cell. It was combined with iodine-131 to produce a radiopharmaceutical for unsealed source radiotherapy, Iodine-131 Tositumomab (branded as Bexxar), fo ...
is an example used for non-Hodgkin's lymphoma.
Antibody-directed enzyme prodrug therapy
Antibody-directed enzyme prodrug therapy (ADEPT) involves the application of cancer-associated monoclonal antibodies that are linked to a drug-activating enzyme. Systemic administration of a non-toxic agent results in the antibody's conversion to a toxic drug, resulting in a cytotoxic effect that can be targeted at malignant cells. The clinical success of ADEPT treatments is limited.
Antibody-drug conjugates
Antibody-drug conjugate
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 phar ...
s (ADCs) are antibodies linked to one or more drug molecules. Typically when the ADC meets the target cell (e.g. a cancerous cell) the drug is released to kill it. Many ADCs are in clinical development. a few have been approved.
Immunoliposome therapy
Immunoliposomes are antibody-conjugated liposomes
A liposome is a small artificial vesicle, spherical in shape, having at least one lipid bilayer. Due to their hydrophobicity and/or hydrophilicity, biocompatibility, particle size and many other properties, liposomes can be used as drug deliver ...
. Liposomes can carry drugs or therapeutic nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules wi ...
s and when conjugated with monoclonal antibodies, may be directed against malignant cells. Immunoliposomes have been successfully used in vivo to convey tumour-suppressing genes into tumours, using an antibody fragment against the human transferrin
Transferrins are glycoproteins found in vertebrates which bind to and consequently mediate the transport of iron (Fe) through blood plasma. They are produced in the liver and contain binding sites for two Fe3+ ions. Human transferrin is encode ...
receptor. Tissue-specific gene delivery using immunoliposomes has been achieved in brain and breast cancer tissue.
Checkpoint therapy
Checkpoint therapy uses antibodies and other techniques to circumvent the defenses that tumors use to suppress the immune system. Each defense is known as a checkpoint. Compound therapies combine antibodies to suppress multiple defensive layers. Known checkpoints include CTLA-4
CTLA-4 or CTLA4 (cytotoxic T-lymphocyte-associated protein 4), also known as CD152 ( cluster of differentiation 152), is a protein receptor that functions as an immune checkpoint and downregulates immune responses. CTLA-4 is constitutively exp ...
targeted by ipilimumab, PD-1
Programmed cell death protein 1, also known as PD-1 and CD279 (cluster of differentiation 279), is a protein on the surface of T and B cells that has a role in regulating the immune system's response to the cells of the human body by down-regula ...
targeted by nivolumab and pembrolizumab
Pembrolizumab, sold under the brand name Keytruda, is a humanized antibody used in cancer immunotherapy that treats melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma, stomach cancer, cervical cancer, and certain types of breast canc ...
and the tumor microenvironment.[
The ]tumor microenvironment
The tumor microenvironment (TME) is the environment around a tumor, including the surrounding blood vessels, immune cells, fibroblasts, signaling molecules and the extracellular matrix (ECM). The tumor and the surrounding microenvironment are ...
(TME) features prevents the recruitment of T cells to the tumor. Ways include chemokine CCL2 nitration, which traps T cells in the stroma. Tumor vasculature helps tumors preferentially recruit other immune cells over T cells, in part through endothelial cell (EC)–specific expression of FasL
Fas ligand (FasL or CD95L or CD178) is a type-II transmembrane protein that belongs to the tumor necrosis factor (TNF) family. Its binding with its receptor induces apoptosis. Fas ligand/receptor interactions play an important role in the regula ...
, ETBR, and B7H3. Myelomonocytic A myelomonocyte is a type of cell observed in chronic myelomonocytic leukemia. It bears a resemblance to both a myelocyte and monocyte. It is derived from CFU-GM
CFU-GM, also known as granulocyte–macrophage progenitor (GMP), is a colony forming ...
and tumor cells can up-regulate expression of PD-L1
Programmed death-ligand 1 (PD-L1) also known as cluster of differentiation 274 (CD274) or B7 homolog 1 (B7-H1) is a protein that in humans is encoded by the ''CD274'' gene.
Programmed death-ligand 1 (PD-L1) is a 40kDa type 1 transmembrane protei ...
, partly driven by hypoxic conditions and cytokine production, such as IFNβ. Aberrant metabolite
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...
production in the TME, such as the pathway regulation by IDO
Ido () is a constructed language derived from Reformed Esperanto, and similarly designed with the goal of being a universal second language for people of diverse backgrounds. To function as an effective ''international auxiliary language'', I ...
, can affect T cell functions directly and indirectly via cells such as Treg cells. CD8 cells can be suppressed by B cells regulation of TAM phenotypes. Cancer-associated fibroblasts
A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework ( stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells o ...
(CAFs) have multiple TME functions, in part through extracellular matrix
In biology, the extracellular matrix (ECM), also called intercellular matrix, is a three-dimensional network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide stru ...
(ECM)–mediated T cell trapping and CXCL12
The stromal cell-derived factor 1 (SDF-1), also known as C-X-C motif chemokine 12 (CXCL12), is a chemokine protein that in humans is encoded by the ''CXCL12'' gene on chromosome 10. It is ubiquitously expressed in many tissues and cell types. Str ...
-regulated T cell exclusion.
FDA-approved therapeutic antibodies
The first FDA-approved therapeutic monoclonal antibody was a murine IgG2a CD3 specific transplant rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient ...
drug, OKT3
Muromonab-CD3 (trade name Orthoclone OKT3, marketed by Janssen-Cilag) is an immunosuppressant drug given to reduce acute rejection in patients with organ transplants. It is a monoclonal antibody targeted at the CD3 receptor, a membrane protein on ...
(also called muromonab), in 1986. This drug found use in solid organ transplant
Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transpo ...
recipients who became steroid
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...
resistant. Hundreds of therapies are undergoing clinical trials
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...
. Most are concerned with immunological and oncological targets.
Tositumomab
Tositumomab is a murine monoclonal antibody which targets the CD20 antigen produced in mammalian cell. It was combined with iodine-131 to produce a radiopharmaceutical for unsealed source radiotherapy, Iodine-131 Tositumomab (branded as Bexxar), fo ...
– Bexxar – 2003 – CD20
B-lymphocyte antigen CD20 or CD20 is expressed on the surface of all B-cells beginning at the pro-B phase ( CD45R+, CD117+) and progressively increasing in concentration until maturity.
In humans CD20 is encoded by the ''MS4A1'' gene.
This gene ...
Mogamulizumab
Mogamulizumab, sold under the brand name Poteligeo, is a humanized, afucosylated monoclonal antibody targeting CC chemokine receptor 4 (CCR4). The U.S. Food and Drug Administration (FDA) approved it in August 2018 for treatment of relapsed or ...
– Poteligeo – August 2018 – CCR4
C-C chemokine receptor type 4 is a protein that in humans is encoded by the ''CCR4'' gene. CCR4 has also recently been designated CD194 (cluster of differentiation 194).
The protein encoded by this gene belongs to the G protein-coupled receptor f ...
Moxetumomab pasudotox
Moxetumomab pasudotox, sold under the brand name Lumoxiti, is an anti- CD22 immunotoxin medication for the treatment of adults with relapsed or refractory hairy cell leukemia (HCL) who have received at least two prior systemic therapies, includin ...
– Lumoxiti – September 2018 – CD22
Cemiplimab – Libtayo – September 2018 – PD-1
Programmed cell death protein 1, also known as PD-1 and CD279 (cluster of differentiation 279), is a protein on the surface of T and B cells that has a role in regulating the immune system's response to the cells of the human body by down-regula ...
Polatuzumab vedotin
Polatuzumab vedotin (INN; brand name Polivy, is an antibody-drug conjugate or ADC designed for the treatment of cancer. The US Food and Drug Administration approved polatuzumab vedotin in June 2019 for treatment of diffuse large B-cell lymphoma ...
– Polivy – June 2019 – CD79B
CD79b molecule, immunoglobulin-associated beta, also known as CD79B (Cluster of Differentiation 79B), is a human gene.
It is associated with agammaglobulinemia-6.
The B lymphocyte antigen receptor is a multimeric complex that includes the antige ...
The bispecific antibodies
A bispecific monoclonal antibody (BsMAb, BsAb) is an artificial protein that can simultaneously bind to two different types of antigen or two different epitopes on the same antigen. Naturally occurring antibodies typically only target one antigen. ...
have yielded promising results in clinical trials. In April 2009, the bispecific antibody catumaxomab
Catumaxomab (trade name Removab) is a rat- mouse hybrid monoclonal antibody which is used to treat malignant ascites, a condition occurring in people with metastasizing cancer. It binds to antigens CD3 and EpCAM. It was developed by Fresenius ...
was approved in the European Union.
Economics
Since 2000, the therapeutic market for monoclonal antibodies has grown exponentially. In 2006, the “big 5” therapeutic antibodies on the market were bevacizumab, trastuzumab
Trastuzumab, sold under the brand name Herceptin among others, is a monoclonal antibody used to treat breast cancer and stomach cancer. It is specifically used for cancer that is HER2 receptor positive. It may be used by itself or together wi ...
(both oncology), adalimumab
Adalimumab, sold under the brand name Humira, among others, is a monoclonal antibody used to treat rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, ulcerative colitis, plaque psoriasis, hidradenitis suppurati ...
, infliximab
Infliximab, a chimeric monoclonal antibody, sold under the brand name Remicade among others, is a medication used to treat a number of autoimmune diseases. This includes Crohn's disease, ulcerative colitis, rheumatoid arthritis, ankylosing spon ...
(both autoimmune and inflammatory disorders, ‘AIID’) and rituximab
Rituximab, sold under the brand name Rituxan among others, is a monoclonal antibody medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin lymphoma, chronic lymphocytic leukemia (in non-geriatric pa ...
(oncology and AIID) accounted for 80% of revenues in 2006. In 2007, eight of the 20 best-selling biotechnology drugs in the U.S. are therapeutic monoclonal antibodies. This rapid growth in demand for monoclonal antibody production has been well accommodated by the industrialization of mAb manufacturing.
References
External links
Cancer Management Handbook: Principles of Oncologic Pharmacotherapy
{{DEFAULTSORT:Monoclonal Antibody Therapy
Immunology
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Antiviral drugs
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