Etanercept
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Etanercept
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| Systematic (IUPAC) name | |
| Unable to be assigned | |
| Identifiers | |
| CAS number | 185243-69-0 |
| ATC code | L04AA11 |
| PubChem | N/A |
| DrugBank | BTD00052 |
| Chemical data | |
| Formula | C2224H3475N621O698S36 |
| Mol. weight | 51234.9 g/mol |
| Pharmacokinetic data | |
| Bioavailability | 58–76% (SC) |
| Metabolism | Reticuloendothelial system (speculative) |
| Half life | 70–132 hours |
| Excretion | ? |
| Therapeutic considerations | |
| Pregnancy cat. | |
| Legal status |
S4 (Au), POM (UK), ℞-only (U.S.) |
| Routes | Subcutaneous |
Etanercept is a recombinant human soluble tumor necrosis factor-alpha (TNFα) receptor. It is a small protein, with a molecular weight of 75 kDa (p75), that binds to TNFα and decreases its role in inflammatory diseases such as rheumatoid arthritis, juvenile rheumatoid arthritis, psoriasis, psoriatic arthritis, and ankylosing spondylitis. In the United States, it is co-marketed by Amgen and Wyeth under the trade name Enbrel®.
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[edit] Development
Etanercept was developed by researchers at biotechnology company Immunex, which was subsequently purchased by Amgen. It was released in 1999, soon after the release of infliximab (Remicade) – the first chimeric monoclonal antibody against TNFα to be marketed for clinical use.
[edit] Mode of action
Tumor necrosis factor-alpha (TNFα) is a cytokine produced by monocytes and macrophages, two types of white blood cells. It mediates the immune response by increasing the transport of white blood cells to sites of inflammation. Inhibition of its action by etanercept reduces the inflammatory response which is especially useful for treating autoimmune diseases.
There are two types of TNF receptors: those found embedded in white blood cells that respond to TNF by releasing other cytokines, and soluble TNF receptors which are used to deactivate TNF and blunt the immune response. Etanercept mimics the inhibitory effects of naturally occurring soluble TNF receptors.
[edit] Structure
Etanercept is made from the combination of two naturally occurring soluble human 75-kilodalton TNF receptors linked to an Fc portion of an IgG1. The effect is an artificially engineered antibody.
[edit] Administration
Enbrel is marketed as a lyophylized powder in 25g vials which must be reconstituted with a diluent and then injected subcutaneously, typically by the patient at home. Because patients with arthritis found the reconstitution procedure difficult, it was made available as pre-filled 50mg/ml syringes in late 2004 and a single-use 50mg autoinjector "pen" was brought to market in mid-2006. It cannot be administered orally, because the digestive system would destroy the drug. FDA approved dose is 25 mg BIW (twice weekly) or 50 mg QW (once weekly).
[edit] Safety
According to the product labeling of infliximab, etanercept, and adalimumab, these drugs are in the class of immunosuppressants. After a number of studies and reports of adverse reactions in patients receiving anti-TNF alpha therapy (including serious and sometimes fatal blood disorders, infections, rare reports of lymphoma and solid tissue cancers, rare reports of serious liver injury, and rare reports of demyelinating central nervous system disorders), rare reports of congestive heart failure, the U.S. Food and Drug Administration issued a warning to doctors appearing in the respective product labeling of these drugs instructing them to screen and monitor potential patients more carefully.
[edit] Sales
Enbrel is the most widely used anti-TNF biologic drug in the field of rheumatology with more patients taking this drug for that indication than either Remicade (infliximab) or Humira (adalimumab). Remicade (infliximab) is the most widely used anti-TNF biologic drug when all FDA approved indications (uses) of the drugs are considered, including Crohn's disease and ulcerative colitis, two autoimmune diseases for which etanercept does not have an FDA approved indication.
[edit] Similar agents
[edit] External links
| Immunosuppressants (L04) edit | ||
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Abetimus, Adalimumab, Afelimomab , Anakinra, Alefacept, Antilymphocyte immunoglobulin (horse), Antithymocyte immunoglobulin (rabbit) , Azathioprine, Basiliximab, Ciclosporin, Daclizumab, Efalizumab, Etanercept, Everolimus, Gusperimus , Infliximab, Leflunomide, Methotrexate , Muromonab-CD3 , Mycophenolic acid, Natalizumab, Pimecrolimus, Tacrolimus, Thalidomide, Sirolimus |
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