グラチラマー酢酸塩、酢酸グラチラマー
出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/11/24 11:24:35」(JST)
Clinical data | |
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AHFS/Drugs.com | monograph |
Licence data | US FDA:link |
Pregnancy category |
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Legal status |
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Identifiers | |
CAS Number | 147245-92-9 Y |
ATC code | L03AX13 |
PubChem | CID: 3081884 |
DrugBank | DB05259 N |
UNII | 5M691HL4BO N |
ChEMBL | CHEMBL1201507 N |
Chemical data | |
Formula | C25H45N5O13 |
Molecular mass | 623.65 g/mol |
N (what is this?) (verify) |
Glatiramer acetate (also known as Copolymer 1, Cop-1, or Copaxone - as marketed by Teva Pharmaceuticals) is an immunomodulator drug currently used to treat multiple sclerosis. It is a random polymer of four amino acids found in myelin basic protein, namely glutamic acid, lysine, alanine, and tyrosine, and may work as a decoy for the immune system. Glatiramer acetate is approved by the Food and Drug Administration (FDA) for reducing the frequency of relapses, but not for reducing the progression of disability. Observational studies, but not randomized controlled trials, suggest that it may reduce progression of disability.
Although the clinical definition of multiple sclerosis requires two or more episodes of symptoms and signs, glatiramer acetate is approved for treatment after single episodes. It is also used to treat relapsing-remitting multiple sclerosis. It is administered by subcutaneous injection.
A 2004 Cochrane review concluded that glatiramer acetate "did not show any beneficial effect on the main outcome measures in MS, i.e. disease progression, and it does not substantially affect the risk of clinical relapses."[1][2]
In its pivotal trial of 251 patients, after two years it failed to show any advantage in halting disability progression.[3][4]
As a result, it is approved by the FDA for reducing the frequency of relapses, but not for reducing the progression of disability.[5]
A 15-year followup of the original trial compared patients who continued with glatiramer to patients who dropped out of the trial. Patients with glatiramer had reduced relapse rates, and decreased disability progression and transition to secondary progressive MS, compared to patients who did not continue glatiramer. However, the two groups were not necessarily comparable, as it was no longer a randomized trial. There were no long-term safety issues.[6]
In two recent studies, both reported at the 2007 ECTRIMS meeting, the efficacy of glatiramer acetate was compared to high-dose/high-frequency interferon beta. In the REGARD study,[citation needed] Rebif was compared to glatiramer, and in the BEYOND study,[citation needed] Betaseron was compared to glatiramer. In both trials, there was no significant difference between interferon and glatiramer in the primary endpoints (time to relapse) or in any clinical endpoints, although some differences in MRI measures of disease activity have been claimed.
A double-blind 3-year study found no effect of glatiramer acetate on Primary-Progressive Multiple Sclerosis.[7]
It has FDA approval for clinically isolated syndrome, based on the PreCISe trial, which showed that glatiramer delayed the progression from the first clinical event to clinically definite multiple sclerosis with a risk reduction of 45%. 43% of patients in the placebo group converted, compared to 25% in the glatiramer group.[8]
According to MediGuard, side effects may include a lump at the injection site (injection site reaction) in approximately 30% of users, and aches, fever, chills (flu-like symptoms) in approximately 10% of users.[9] Side effect symptoms are generally mild in nature. A reaction that involves flushing, shortness in breath, anxiety and rapid heartbeat has been reported soon after injection in up to 5% of patients (usually after injecting directly into a vein). These side effects subside within thirty minutes. Over time, a visible dent at the injection site can occur due to the local destruction of fat tissue, known as lipoatrophy, that may develop.
More serious side effects have been reported for glatiramer acetate, according to the FDA's prescribing label, these include serious side effects to the cardiovascular, digestive (including the liver), hematopoietic, lymphatic, musculoskeletal, nervous, respiratory, and urogenital systems as well as special senses (in particular the eyes). Metabolic and nutritional disorders have also been reported; however a link between glatiramer acetate and these adverse effects has not been established.[10]
Glatiramer acetate is a random polymer (average molecular mass 6.4 kD) composed of four amino acids found in myelin basic protein. The mechanism of action for glatiramer acetate is unknown. Administration of glatiramer acetate shifts the population of T cells from proinflammatory Th1 cells to regulatory Th2 cells that suppress the inflammatory response.[11] Given its resemblance to myelin basic protein, glatiramer acetate may also act as a decoy, diverting an autoimmune response against myelin. The integrity of the blood brain barrier, however, is not appreciably affected by glatiramer acetate, at least not in the early stages of treatment. Glatiramer acetate has been shown in clinical trials to reduce the number and severity of multiple sclerosis exacerbations.[12]
The mechanism(s) by which glatiramer acetate exerts its effects in patients with Multiple Sclerosis (MS) is (are) not fully elucidated. However, it is thought to act by modifying immune processes that are currently believed to be responsible for the pathogenesis of MS. This hypothesis is supported by findings of studies that have been carried out to explore the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a condition induced in several animal species through immunization against central nervous system derived material containing myelin and often used as an experimental animal model of MS. Studies in animals and in vitro systems suggest that upon its administration, glatiramer acetate-specific suppressor T-cells are induced and activated in the periphery.[13]
Glatiramer acetate was originally discovered by Prof. Michael Sela, Prof. Ruth Arnon and Dr. Dvora Teitelbaum at the Weizmann Institute of Science in Rehovot, Israel. The efficacy and safety of glatiramer acetate were demonstrated in three main clinical trials. The first trial, led by Professor Murray Bornstein, was performed in a single center, double-blind, placebo controlled trial and included 50 patients.[14] The second trial was a two-year, multi-center, randomized, double-blind, placebo controlled trial and was performed in eleven United States centers involving 251 patients. This study was led by Professor Kenneth Johnson, Chairman of the Department of Neurology, University of Maryland Medical Center, Baltimore.[15] The third trial, a double-blind, multi-center, multi-country MRI study, involved 29 MS Centers in six European countries and Canada, with the participation of 239 patients. This study was led by Professor G. Comi, Department of Neuroscience, San Raffaele Hospital, the University of Milan.[16]
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Glatiramer acetate has been approved for marketing in 49 countries worldwide, including the United States, Israel, Canada and 24 European Union Countries.
Approval in the U.S. was obtained in 1996. Glatiramer acetate was approved for marketing in the U.K. in August 2000, and launched in December. This first approval in a major European market enabled Teva to file for approval all over the European Union under the mutual recognition procedure.
Glatiramer has been found to be protective in a mouse model of cerebral malaria.[17]
Glatiramer is currently[when?] in Phase I clinical trials for Dry Age-Related Macular Degeneration (AMD).
In 2015 researchers presented results of a small, uncontrolled study of Glatiramer acetate given to girls with Rett Syndrome; Glatiramer was associated with improvement in symptoms. [18]
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リンク元 | 「copolymer-1」「酢酸グラチラマー」 |
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