Maraviroc, sold under the brand names Selzentry (US) and Celsentri (EU), is an

antiretroviral medication Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do n ...

used to treat

HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...

infection. It is taken

by mouth Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...

. It is in the

CCR5 receptor antagonist CCR5 receptor antagonists are a class of small molecules that antagonize the CCR5 receptor. The C-C motif chemokine receptor CCR5 is involved in the process by which HIV, the virus that causes AIDS, enters cells. Hence antagonists of this rec ...

class. It was approved for medical use in the United States in August 2007, and in the European Union in September 2007.

Medical uses

Maraviroc is

indicated In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...

, in combination with other antiretroviral medications, for the treatment of only CCR5-tropic HIV-1 infection.

Side effects

Maraviroc can cause serious, life-threatening side effects. These include liver problems, skin reactions, and allergic reactions. An allergic reaction may happen before liver problems occur. Official labeling of Selzentry has

black box warning In the United States, a boxed warning (sometimes "black box warning", colloquially) is a type of warning that appears on the package insert for certain prescription drugs, so called because the U.S. Food and Drug Administration specifies that it i ...

for

hepatotoxicity Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn fro ...

. The MOTIVATE trials showed no clinically relevant differences in safety between the maraviroc and placebo groups.

Mechanism of action

Maraviroc is an

entry inhibitor Entry inhibitors, also known as fusion inhibitors, are a class of antiviral drugs that prevent a virus from entering a cell, for example, by blocking a receptor. Entry inhibitors are used to treat conditions such as HIV and hepatitis D. HIV entr ...

. Specifically, maraviroc is a negative

allosteric modulator In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a Receptor (biochemistry), receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allos ...

of the

CCR5 C-C chemokine receptor type 5, also known as CCR5 or CD195, is a protein on the surface of white blood cells that is involved in the immune system as it acts as a receptor for chemokines. In humans, the ''CCR5'' gene that encodes the CCR5 pro ...

receptor, which is found on the surface of certain human cells. The

chemokine Chemokines (), or chemotactic cytokines, are a family of small cytokines or signaling proteins secreted by cells that induce directional movement of leukocytes, as well as other cell types, including endothelial and epithelial cells. In additio ...

receptor CCR5 is an essential co-receptor for most HIV strains and necessary for the entry process of the virus into the host cell. The drug binds to CCR5, thereby blocking the HIV protein

gp120 Envelope glycoprotein GP120 (or gp120) is a glycoprotein exposed on the surface of the HIV envelope. It was discovered by Professors Tun-Hou Lee and Myron "Max" Essex of the Harvard School of Public Health in 1988. The 120 in its name comes from ...

from associating with the receptor.

is then unable to enter human

macrophage Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cel ...

s and

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 ...

s. Because HIV can also use other coreceptors, such as

CXCR4 C-X-C chemokine receptor type 4 (CXCR-4) also known as fusin or CD184 (cluster of differentiation 184) is a protein that in humans is encoded by the ''CXCR4'' gene. The protein is a CXC chemokine receptor. Function CXCR-4 is an alpha-chemokin ...

, an

HIV tropism HIV tropism refers to the cell type in which the human immunodeficiency virus ( HIV) infects and replicates. HIV tropism of a patient's virus is measured by the Trofile assay. HIV can infect a variety of cells such as CD4+ helper T-cells and m ...

test such as a trofile assay must be performed to determine if the drug will be effective.

History

Maraviroc, originally designated UK-427857, was developed by the drug company

Pfizer Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered on 42nd Street in Manhattan, New York City. The company was established in 1849 in New York by two German entrepreneurs, Charles Pfizer ...

in its UK labs located in

Sandwich A sandwich is a food typically consisting of vegetables, sliced cheese or meat, placed on or between slices of bread, or more generally any dish wherein bread serves as a container or wrapper for another food type. The sandwich began as a po ...

. On 24 April 2007 the U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

advisory panel reviewing maraviroc's New Drug Application unanimously recommended approval for the new drug, and the drug received full FDA approval on 6 August 2007 for use in treatment experienced patients. Two randomized, placebo-controlled

clinical trial 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 ...

s, compared 209 people receiving optimized therapy plus a

placebo A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures. In general ...

to 426 people receiving optimized therapy plus 150 mg maraviroc once daily and 414 patients receiving optimized therapy plus 150 mg maraviroc twice daily. At 48 weeks, 55% of participants receiving maraviroc once daily and 60% of participants receiving the drug twice daily achieved a

viral load Viral load, also known as viral burden, is a numerical expression of the quantity of virus in a given volume of fluid, including biological and environmental specimens. It is not to be confused with viral titre or viral titer, which depends on the ...

of less than 400 copies/mL compared with 26% of those taking placebo; about 44% of the once-daily and 45% of the twice-daily maraviroc group had a viral load of less than 50 copies/mL compared with about 23% of those who received placebo. In addition, those who received the

had a mean increase in CD4⁺ cells of 110 cells/μL in the once-daily group, 106 cells/μL in the twice-daily group, and 56 cells/μL in the placebo group. Maraviroc was approved for medical use in the European Union in September 2007.

Names

Maraviroc is the International nonproprietary name (INN).

Research

Maraviroc appears to reduce

graft-versus-host disease Graft-versus-host disease (GvHD) is a syndrome, characterized by inflammation in different organs. GvHD is commonly associated with bone marrow transplants and stem cell transplants. White blood cells of the donor's immune system which remain wit ...

in people treated with

allogeneic bone marrow transplantation Allotransplant (''allo-'' meaning "other" in Greek) is the transplantation of cells, tissues, or organs to a recipient from a genetically non-identical donor of the same species. The transplant is called an allograft, allogeneic transplant, o ...

for

leukemia Leukemia ( also spelled leukaemia and pronounced ) is a group of blood cancers that usually begin in the bone marrow and result in high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or ' ...

, in a Phase I/II study.

References

External links

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