Etanercept: an updated review of its use in rheumatoid arthritis,psoriatic arthritis and juvenile rheumatoid arthritis

Etanercept is a subcutaneously administered biological response modifier that binds and inactivates tumour necrosis factor-alpha, a proinflammatory cytokine. In patients with early active rheumatoid arthritis, etanercept 25mg twice weekly was associated with a more rapid improvement in disease activity and a significantly greater cumulative response than methotrexate over 12 months of treatment in a randomised, double-blind trial. In addition, etanercept recipients showed a slower rate of radiographic progression and a more rapid improvement in quality of life than methotrexate recipients. The efficacy of etanercept was maintained at 3 years' follow-up. Etanercept was also significantly better than placebo at reducing disease activity in patients who had an inadequate response to previous treatment with disease-modifying antirheumatic drugs (DMARDs) in several well controlled trials. At study end (after 3 or 6 months' treatment), the percentage of patients achieving an American College of Rheumatology 20% (ACR20) response with etanercept (25mg or 16 mg/m(2) twice weekly) was 59 to 75% as monotherapy and 71% in combination with methotrexate; corresponding placebo response rates were 11 to 14% and 27%, respectively. Response has been maintained in patients who continued treatment for up to 5 years. In patients with psoriatic arthritis, etanercept 25mg twice weekly significantly reduced disease activity and improved skin lesions in two double-blind, placebo-controlled, 12- to 24-week trials. In the 24-week study, ACR20 response rates (50 vs 13%), psoriatic arthritis response rates (70 vs 23%) and the median improvement in skin lesions (33 vs 0%) were significantly greater in etanercept than in placebo recipients. In patients with polyarticular-course juvenile rheumatoid arthritis, etanercept resulted in improvements in all measures of disease activity and was significantly more effective than placebo at reducing disease flare. Eighty percent of patients receiving etanercept achieved a >or=30% reduction in disease activity over 7 months of treatment, and this was maintained for up to 2 years in a trial extension. Etanercept was generally well tolerated in children and adults in clinical trials; the most commonly occurring adverse effects included injection site reactions, infection, headache, rhinitis and dizziness. In conclusion, etanercept has emerged as an important new treatment option in inflammatory arthritis. Etanercept provides rapid and sustained improvements in disease activity in patients with early and DMARD-refractory rheumatoid arthritis and has been shown to inhibit radiographic progression in those with early disease. Well controlled studies have also demonstrated the efficacy of etanercept in patients with psoriatic arthritis or polyarticular-course juvenile rheumatoid arthritis.     

Etanercept: a review of its use in the management of rheumatoid arthritis

Etanercept (Enbrel), a soluble fusion protein that binds specifically to the cytokine human tumour necrosis factor (TNF), is approved for subcutaneous use in the treatment of patients with moderate to severe active rheumatoid arthritis, juvenile rheumatoid arthritis, psoriatic arthritis, ankylosing arthritis and plaque psoriasis in the US, Italy, the rest of the EU and other countries worldwide. Subcutaneous etanercept was efficacious and generally well tolerated in several large, well designed, clinical trials and in the clinical-practice setting in adult patients with rheumatoid arthritis, including methotrexate-naive patients with early disease and those with long-standing, treatment-resistant active disease. Etanercept plus methotrexate combination therapy was generally superior to either monotherapy in reducing disease activity and structural joint damage, as well as improving health-related quality of life (HR-QOL). Furthermore, etanercept monotherapy was superior to placebo and at least as effective as methotrexate therapy in reducing disease activity and improving HR-QOL in patients with early or refractory disease. The beneficial effects of etanercept monotherapy or combination therapy were sustained in the long term (< or =9 years). Some pharmaco-economic analyses suggest that etanercept is a cost-effective option in the treatment of patients with rheumatoid arthritis. Direct head-to-head comparisons with other biological agents would help to definitively position etanercept with respect to these agents. Nevertheless, extensive clinical experience indicates that etanercept is a valuable treatment option in adult patients with long-standing moderate to severe active rheumatoid arthritis and an emerging option in those with early disease.     

Anti-TNF agents for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory, autoimmune disease with a prevalence of approximately 1% and an annual incidence of 0.04%. Up to 50% of patients with RA are unable to work 10 years after diagnosis. The disease is associated with significant morbidity and mortality with associated medical costs to the UK of between £240 m and £600 m per year.Non steroidal anti-inflammatory drugs (NSAIDs) have little effect on the underlying course of RA, but they have some anti-inflammatory and analgesic properties. Disease modifying antirheumatic drugs (DMARDs) have been shown to slow progression of RA and are currently recommended early in the course of treatment of RA which is when disease progression is most rapid.Etanercept and infliximab belong to a new group of parentally administered antitumour necrosis factor (TNF) drugs.Etanercept is licensed in the UK for the treatment of active rheumatoid arthritis in patients who have not responded to other DMARDs and in children with polyarticular-course juvenile arthritis who have not responded to or are intolerant of methotrexate. In adults it produces significant improvements in all measures of rheumatic disease activity compared to placebo. In patients whose disease remains active despite methotrexate treatment, further improvement in control is obtained with the addition of etanercept without an increase in toxicity. In one small trial, etanercept was found to be more effective than placebo in a selected group of children.Infliximab is a monoclonal antibody which is currently licensed in the UK for Crohn''s disease and, in combination with methotrexate for the treatment of rheumatoid arthritis in patients with active disease when the response to disease-modifying drugs, including methotrexate, has been inadequate. In clinical trials infliximab produced significant improvements in all measures of rheumatic disease activity compared with placebo. Infliximab in combination with methotrexate was shown to be superior to methotrexate or infliximab alone.There are currently no predictors of a good response to anti-TNF drugs and a percentage of patients fail to respond to treatment (25% to 38% of etanercept patients; 21% to 42% of infliximab patients). Infliximab monotherapy induces the production of anti-infliximab antibodies, which may reduce its effectiveness. Adding methotrexate to infliximab therapy may prevent this response.Anti-TNF drugs may affect host defences against infection and malignancy; whether these agents affect the development and course of malignancies and chronic infections is unknown and safety and efficacy in patients with immunosuppression or chronic infections has not been investigated. With infliximab, upper respiratory tract infections, general infections and those requiring antimicrobial treatment were more common in patients than placebo. Likewise, upper respiratory tract infections were more common in patients treated with etanercept than with placebo. Injection site reactions occur with both infliximab (16%–20%) and etanercept (37%).There are approximately 600 000 patients with RA in the UK, and of these between 2% and 3.5% may have severe disease which has failed to respond to conventional treatment and who might be eligible for anti-TNF therapy. If between 50% and 70% of patients treated with anti-TNF drugs respond and continue on long-term treatment then the recurrent annual cost to the NHS could be between £48 m and £129 m.     

Tumour necrosis factor-α blockade: a new era for effective management of rheumatoid arthritis

Tumour necrosis factor (TNF)-α inhibitors have emerged as a new treatment option for rheumatoid arthritis (RA). The scientific rationale for targeting TNF-α in RA derives from extensive work in the laboratory, showing the importance of this pro-inflammatory cytokine as a mediator of joint inflammation. Proof of principle has now been firmly established in clinical trials where TNF-α inhibitors have been shown to decrease the signs and symptoms of joint inflammation and slow radiological progression of joint damage. Presently, the two TNF-α inhibitors available for use in RA are etanercept and infliximab. Etanercept is a soluble TNF receptor: Fc fusion protein that competes with the endogenous TNF receptors for TNF-α binding. Infliximab is a chimeric anti-TNF-α monoclonal antibody, which also binds with high affinity to soluble TNF-α. Etanercept and infliximab will be rapidly incorporated into current treatment paradigms, which call for early and intensive treatment of RA using disease-modifying antirheumatic drugs (DMARDs), such as methotrexate, sulfasalazine and hydroxychloroquine. A major drawback to the widespread use of these biologics is their high costs. Some patients with limited financial means may be denied access to these effective anti-inflammatory agents. Moreover, long-term experience with TNF-α inhibitor therapy has been limited and concerns linger about the possibility that etanercept and infliximab may cause unforeseen side effects or increase the risk for opportunistic infection. Despite these caveats, TNF-α inhibitors represent a major advance for the treatment of RA and will likely spawn new indications for anti-TNF-α therapy and the development of novel therapeutic compounds with similar biological activity.     

Tumour necrosis factor-alpha blockade: a new era for effective management of rheumatoid arthritis

Tumour necrosis factor (TNF)-alpha inhibitors have emerged as a new treatment option for rheumatoid arthritis (RA). The scientific rationale for targeting TNF-alpha in RA derives from extensive work in the laboratory, showing the importance of this pro-inflammatory cytokine as a mediator of joint inflammation. Proof of principle has now been firmly established in clinical trials where TNF-alpha inhibitors have been shown to decrease the signs and symptoms of joint inflammation and slow radiological progression of joint damage. Presently, the two TNF-alpha inhibitors available for use in RA are etanercept and infliximab. Etanercept is a soluble TNF receptor: Fc fusion protein that competes with the endogenous TNF receptors for TNF-alpha binding. Infliximab is a chimeric anti-TNF-alpha monoclonal antibody, which also binds with high affinity to soluble TNF-alpha. Etanercept and infliximab will be rapidly incorporated into current treatment paradigms, which call for early and intensive treatment of RA using disease-modifying antirheumatic drugs (DMARDs), such as methotrexate, sulfasalazine and hydroxychloroquine. A major drawback to the widespread use of these biologics is their high costs. Some patients with limited financial means may be denied access to these effective anti-inflammatory agents. Moreover, long-term experience with TNF-alpha inhibitor therapy has been limited and concerns linger about the possibility that etanercept and infliximab may cause unforeseen side effects or increase the risk for opportunistic infection. Despite these caveats, TNF-alpha inhibitors represent a major advance for the treatment of RA and will likely spawn new indications for anti-TNF-alpha therapy and the development of novel therapeutic compounds with similar biological activity.     

Etanercept: efficacy and safety for approved indications

INTRODUCTION: Etanercept is a tumor necrosis factor alpha (TNF-α) inhibitor, which is approved for the treatment of immune-mediated inflammatory conditions including rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), psoriatic arthritis (PsA), ankylosing spondylitis (AS) and psoriasis (PsO). AREAS COVERED: Clinical efficacy and safety data of etanercept for the approved indications are reviewed in this paper. Data were obtained from published clinical trials, registries, post-marketing data as well as information provided by Amgen. EXPERT OPINION: Etanercept is a generally well-tolerated treatment for the approved inflammatory diseases. The most common adverse effect of etanercept treatment is injection site reaction, which is generally self-limiting and often does not require treatment. Etanercept may be associated with an increased risk for infection, the development of malignancy, demyelinating disease and congestive heart failure. Fewer patients withdraw from etanercept due to adverse events than with other biologics. For pediatric patients, there are more data for etanercept than other biologics, and etanercept may have lower rates for the development of malignancy.     

Etanercept: a pharmacoeconomic review of its use in rheumatoid arthritis

Etanercept (Enbrel), which inhibits the activity of tumour necrosis factor-alpha, is indicated in the treatment of patients with active rheumatoid arthritis (RA). A lifetime cost-utility analysis in patients with severe disease-modifying antirheumatic drug (DMARD)-resistant RA in the UK suggested that etanercept is associated with acceptable cost-utility ratios relative to traditional nonbiological DMARDs. In a 12-month cost-utility study in Spain, etanercept was predicted to be dominant over infliximab plus methotrexate in patients with active, refractory RA with regards to the cost per QALY gained and cost per American College of Rheumatology (ACR) 20 response achieved. In short-term cost-effectiveness analyses conducted in the US, the cost effectiveness of etanercept relative to other treatments in patients with methotrexate-naive or -resistant RA depends on whether predicted incremental cost-effectiveness ratios of at least USD 41,900 per ACR 20 response or USD 34,800 per ACR 70 weighted response over a 6-month period are considered acceptable (1999 values). The relative efficacy and cost effectiveness of etanercept and other biological DMARDs will be clarified when appropriate data from directly comparative clinical and/or long-term pharmacoeconomic studies become available. Etanercept may prevent or delay disability, which may produce reductions in nondrug costs that could help offset its acquisition cost.     

Etanercept: a review of its use in rheumatoid arthritis.

Etanercept, a fusion protein consisting of the extracellular ligand-binding domain of the 75kD receptor for tumour necrosis factor-alpha and the constant portion of human IgG1, is administered by subcutaneous injection and is the first specific anti-cytokine therapy approved for rheumatoid arthritis. In patients with active rheumatoid arthritis [American College of Rheumatology (ACR) functional class I to III] who had failed to respond to previous treatment with > or = 1 disease-modifying antirheumatic drug (DMARD), etanercept, alone or in combination with methotrexate, produced improvements in all components included in the ACR core set of disease activity measures. A dose-response effect was apparent with etanercept 0.25 to 16 mg/m2 twice weekly in a randomised, double-blind study in 180 patients. The mean number of swollen or tender joints at the end of the 12-week study decreased by >50% in patients treated with etanercept 16 mg/m2 twice weekly and by <25% in patients treated with placebo. In a 24-week multicentre, randomised, double-blind study in 234 patients who were not allowed to use DMARDs, etanercept 10 or 25mg twice weekly had a rapid onset of effect. Significantly more patients treated with etanercept 25mg twice weekly than placebo experienced 20 (ACR 20), 50 (ACR 50) or 70% (ACR 70) improvement in ACR criteria after 3 and 6 months. Limited evidence suggests that the therapeutic effects of etanercept are maintained for up to 2 years. Etanercept 25mg twice weekly produced significant improvement in patients receiving oral or subcutaneous methotrexate 10 to 25 mg/week in a multicentre, randomised, double-blind, placebo-controlled study. A significantly greater proportion of patients treated with etanercept plus methotrexate (71%) than placebo plus methotrexate (27%) achieved the ACR 20 criteria after 6 months. Moreover, 39 and 15% of patients treated with etanercept plus methotrexate, but no placebo plus methotrexate recipients, had achieved the ACR 50 and ACR 70 criteria at this time. Etanercept 0.4 mg/kg twice weekly reduced disease activity in a preliminary, noncomparative study in 69 children aged > or =4 years with refractory juvenile rheumatoid arthritis. Although the overall frequency of infections was similar in patients treated with etanercept or placebo, upper respiratory tract infections were more common in patients treated with etanercept (29%) than placebo (16%). Injection site reactions occurred more frequently in etanercept- than placebo-treated patients, but did not bias the results of any study. CONCLUSIONS: When etanercept is administered alone or in combination with methotrexate in patients with refractory rheumatoid arthritis, significant reductions in disease activity occur within 2 weeks and are sustained for at least 6 months. Thus, etanercept appears to be particularly well suited for use in patients who fail to respond to treatment with DMARDs.     

Etanercept in rheumatoid arthritis

Etanercept (Enbrel^?, Immunex Corporation, Seattle, Washington, USA) is a new biological disease-modifying antirheumatic drug (DMARD) for the treatment of active rheumatoid arthritis (RA). It is one of two TNF-α blockers to be licensed for the treatment of active RA and is classified as a recombinant human soluble TNF receptor. The drug competitively inhibits the binding of TNF to cell surface receptors and thus renders TNF biologically inactive. In doing so, etanercept inhibits the pro-inflammatory effects of TNF and results in a reduction of joint inflammation in patients with RA. Etanercept has shown a statistically significant reduction in swollen and inflamed joint counts, biochemical markers such as erythrocyte sedimentation rate and C-reactive protein and shown significant improvements in quality of life measures (HAQ and global assessment scores) in all studies. In early disease, etanercept has shown a reduction in joint space narrowing equal to methotrexate (MTX) and a reduction in the appearance of new erosions significantly better than MTX after 1 year of treatment. Etanercept has a rapid onset of action which is significantly faster than standard DMARDs. Etanercept was well-tolerated in clinical trials. The commonest side effects were injection site reactions and upper respiratory tract infections. Etanercept therapy has resulted in serious infections in some patients and should be used with caution in any patient with a history of recurring infections or with disease states that may predispose to infections. In summary, etanercept is an effective and well-tolerated agent that is a significant breakthrough in the treatment of this disabling condition.     

Etanercept in rheumatoid arthritis

Etanercept (Enbrel, Immunex Corporation, Seattle, Washington, USA) is a new biological disease-modifying antirheumatic drug (DMARD) for the treatment of active rheumatoid arthritis (RA). It is one of two TNF-alpha blockers to be licensed for the treatment of active RA and is classified as a recombinant human soluble TNF receptor. The drug competitively inhibits the binding of TNF to cell surface receptors and thus renders TNF biologically inactive. In doing so, etanercept inhibits the pro-inflammatory effects of TNF and results in a reduction of joint inflammation in patients with RA. Etanercept has shown a statistically significant reduction in swollen and inflamed joint counts, biochemical markers such as erythrocyte sedimentation rate and C-reactive protein and shown significant improvements in quality of life measures (HAQ and global assessment scores) in all studies. In early disease, etanercept has shown a reduction in joint space narrowing equal to methotrexate (MTX) and a reduction in the appearance of new erosions significantly better than MTX after 1 year of treatment. Etanercept has a rapid onset of action which is significantly faster than standard DMARDs. Etanercept was well-tolerated in clinical trials. The commonest side effects were injection site reactions and upper respiratory tract infections. Etanercept therapy has resulted in serious infections in some patients and should be used with caution in any patient with a history of recurring infections or with disease states that may predispose to infections. In summary, etanercept is an effective and well-tolerated agent that is a significant breakthrough in the treatment of this disabling condition.     

Efficacy and safety of etanercept in chronic immune-mediated disease

Introduction: TNF-α inhibitors have demonstrated efficacy in large, randomized controlled clinical trials either as monotherapy or in combination with other anti-inflammatory or disease-modifying antirheumatic drugs in the treatment of chronic inflammatory immune-mediated diseases. Etanercept is a fusion protein that acts as a ‘decoy receptor’ for TNF-α.

Areas covered: This paper evaluates the efficacy and safety of etanercept in patients with chronic inflammatory immune-mediated diseases.

Expert opinion: Etanercept was first approved for the treatment of rheumatoid arthritis (RA) and subsequently of chronic plaque psoriasis, psoriatic arthritis, ankylosing spondylitis and juvenile RA. Etanercept as other TNF-α inhibitors, particularly infliximab, may be administered off-label to treat other chronic inflammatory immune-mediated diseases such as systemic sclerosis, Behcet disease, systemic lupus erythematosus, polymyositis, dermatomyositis and mixed connective tissue disease. Early etanercept treatment prevents joint damage and helps to avoid long-term disability in arthritis. Etanercept administered at a dose of 50 mg once weekly is effective in inducing an earlier remission of RA, and etanercept 50 mg twice weekly may favor a more rapid improvement of psoriasis and psoriatic arthritis. Etanercept and adalimumab may exert beneficial effects on lipid profile and improve endothelial dysfunction. Appropriate screening tests for latent tuberculosis, hepatitis B virus and hepatitis C virus should be performed before starting etanercept. TNF-α inhibitors including etanercept are contraindicated in patients with demyelinating diseases.     

Etanercept Immunex

Immunex has developed and launched etanercept, a soluble TNF receptor (TNFR) fusion protein, for the treatment of early and moderate to severely active rheumatoid arthritis (RA). Etanercept was launched as a first-line agent in the US for the treatment of moderate-to-severe active RA in June 2000 [375481]. It can also be used in conjunction with methotrexate (MTX) in patients who do not respond adequately to MTX alone [303266], [310436]. It was launched in the EU in November 2000 [388846]. Enbrel was also launched for the treatment of polyarticular-course juvenile RA (JRA) patients who have an inadequate response to one or more disease-modifying antirheumatic drugs (DMARDs) in May 1999. Additionally, it is in phase III trials for psoriatic arthritis and a BLA filing for this indication is expected for the first half of 2001 [364948]. Etanercept was launched in the US in November 1998, for the treatment of moderate-to-severe RA in patients with inadequate responses to one or more DMARDs, or in combination with MTX in patients who do not respond adequately to MTX alone [306175]. The drug was subsequently approved by the US FDA for use as a first-line therapy to treat patients with moderately to severely active RA [375481]. In February 2000, Wyeth Europe received clearancefor etanercept in 15 EU countries by the EMEA for the treatment of active arthritis in adults when the response to DMARDs has been inadequate [354844]. It has since been launched in the UK (June 2000) [388840], and by October 2000 had been launched in all EU member states [388846]. In November 1998, the company filed a supplemental BLAfor the treatment of children and teenagers with moderately to severely active polyarticular course JRA. In May 1999, etanercept was approvedfor this indication by the US FDA and approvedfor this indication in Europe in February 2000 [307061], [310436], [326379]. The increasing understanding of the role of TNF in a number of other diseases has led to its clinical assessment in these areas. Following positive clinical results in phase II studies [317562], [315793], (320666], (359789], (373980] in patients with chronic heart failure, etanercept entered phase III trials for this indication in June 1999 [330068], and a BLA filing for this indication is expected in 2003 [396110]. Additionally, Immunex initiated a phase III trial of etanercept in psoriatic arthritis in March 2000, and as of May 2000, the company was planning a BLA filing for this indication in the first half of 2001 [364948]. An open-label trialfor the treatment of Crohn's disease is in progress in Belgium [367,039], and results from this trial were presented at Digestive Disease Week in May 2000 [379907]. While WO-09103553 claims the recombinant human receptor, the fusion protein consisting of the etanercept domain and the immunoglobulin region was disclosed in WO-09406476. In February 1997, US-05605690 was issued to Immunex for methods of using etanercept to treat diseases mediated by TNF. The patent also claims methods of using recombinant etanercept to decrease the levels of TNF in RA patients [235456]. In June 1999, Immunex strengthened its patent estate covering the product with a patent licensing agreement for Genentech's immunoadhesin patents covering the product [327250]. A royalty agreement with Serono SA and Immunex on sales of etanercept was agreed in 1999. The agreement reflected the strength of Ares-Serono's intellectual property status [352813]. In June 1999, Lehman Brothers predicted Immunex's sales at US $300 million in 1999, rising to peak annual sales of US $1.5 billion [328701]. Salesfor the drug's first full quarter on the market in 1999 were US $59.7 million [330068]. By November 1999 the drug had made sales of US $500 million; Immunex expects the drug will generate over US $2 billion in annual sales by 2004 [353185]. In September 2000, Merrill Lynch reported that if sales of the drug continue at the present rate then it is likely that demand will temporarily outstrip supply in 2001. Resolution of the supply issue is expected by 2002. Also in September 2000, Merrill Lynch lowered their estimate of ENBREL sales in 2001 from US $1 billion to $927 million. In the long-term, Merrill Lynch believe that the drug has the potential to exceed US $5 billion in sales in the US [382577].     

Etanercept: new preparation. Useful after methotrexate failure in inflammatory rheumatism

There is no reference second-line treatment for patients with rheumatoid arthritis, juvenile chronic arthritis, psoriatic arthropathy or ankylosing spondylitis after failure or intolerance of a slow-acting antirheumatic drug such as methotrexate. Etanercept, a immunosuppressant targeting TNF-alpha (like infliximab), is now approved in France for use in these situations, with the exception of spondylitis. In the second-line treatment of adults with rheumatoid arthritis, the clinical evaluation dossier on etanercept contains data from dose-finding studies and two placebo-controlled trials involving patients in whom several single-agent treatments had failed. At a dose of 25 mg subcutaneously twice a week, etanercept worked partially in about half the patients. Without direct comparisons, the place of etanercept relative to other slow-acting antirheumatic drugs is difficult to establish. From indirect comparisons, etanercept seems a slightly better treatment option than infliximab. In the first-line treatment of rheumatoid arthritis, one trial showed that etanercept worked faster than methotrexate, but there was no significant difference between the two treatments after two years. Little is known about the efficacy of etanercept in patients with juvenile chronic arthritis who do not respond adequately to methotrexate. There are no comparative trials. One double-blind placebo-controlled trial showed that etanercept, when it worked, remained active for at least 7 months. In one trial, etanercept was more effective than placebo in patients with psoriatic arthropathy and ankylosing spondylitis who continued to receive their usual treatment, which included a slow-acting antirheumatic drug in about 50% of cases. More than 50% of patients treated with etanercept have a cutaneous reaction to the injection. These reactions are usually mild or moderate. Active pharmacovigilance is needed, given its mechanism of action, and previous notifications of a wide variety of adverse effects (even though it is sometimes difficult to establish a foolproof link between etanercept and the adverse effect). Long-term studies of large numbers of patients are needed to determine the precise risk of side effects including haematological, infectious, neurological, oncological and immunological effects. In practice, methotrexate remains the first-line treatment for inflammatory arthritis. Etanercept can be a useful second-line treatment, especially in juvenile chronic arthritis.     

Approaches to the treatment of early rheumatoid arthritis with disease-modifying antirheumatic drugs

This paper reviews recent approaches to treatment of early rheumatoid arthritis (RA) with disease-modifying antirheumatic drugs (DMARDs). The literature on treatment the early RA published between 1995 and 2007 was accessed through the PubMed database from the National Library of Medicine. Keywords were 'early rheumatoid arthritis', 'disease-modifying antirheumatic drugs', 'biologic agents' and 'combination therapy'. Only results of trials on human subjects that directly measured the effects of DMARDs or biological agents on clinical, laboratory parameters and radiological progression of early RA were selected. Combination therapy suppresses RA activity and radiological progression more effectively than monotherapy. If better control of RA is evident after 3–6 months of treatment with the combination of DMARDs, one must still decide whether to stop the first DMARD, stop the second, or continue with the combination. Combination therapy biological agents (infliximab, adalimumab) with methotrexate and etanercept therapy alone may induce remission in many patients with early RA. It is a method of choice in patients with an adverse prognosis. The main indications for combination therapy 'standard' DMARDs or combination 1 DMARDs with a biological agent are such variables as detection of a shared epitope, increase of concentration of anticyclic citrullinated peptide antibodies, rheumatoid factor, C-reactive protein, 28-joint disease activity score, Sharp score and presence of erosion in joints. The majority of rheumatologists believe that patients with RA should be treated with DMARDs earlier rather than later in the disease process. Further trials should establish the optimal approaches to early RA therapy.     

TNF inhibitors in the treatment of arthritis

Rheumatoid arthritis (RA) is a chronic destructive arthritis leading to joint destruction as a consequence of chronic inflammatory processes. Established therapy with slow-acting disease-modifying anti-rheumatic drugs (DMARDs), as with low-dose methotrexate (MTX), leads to a significant improvement of disease symptoms, but are unable to stop joint destruction. Novel therapeutic agents like monoclonal antibodies (mAb), cytokine receptor-human immunoglobulin constructs or recombinant human proteins have been tested in RA and in other chronic arthritides like ankylosing spondylitis or psoriatic arthritis with convincing success. In particular, clinical trials testing anti-TNF alpha agents either alone or in combination with MTX have proven the feasibility and efficacy of these novel approaches.     

Clinical pharmacokinetics of etanercept: a fully humanized soluble recombinant tumor necrosis factor receptor fusion protein

Etanercept, a fully humanized soluble recombinant tumor necrosis factor receptor fusion protein, is an approved treatment for rheumatoid arthritis, juvenile rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and psoriasis. Etanercept is absorbed slowly from the site of subcutaneous injection, with time to peak concentration at approximately 48 to 60 hours, and is cleared slowly from the body with a t(1/2) of 70 to 100 hours. The absolute bioavailability of etanercept was 58% in healthy subjects following subcutaneous administration. The 25-mg twice-weekly dosage regimen generates systemic exposures comparable to 50 mg once weekly, as predicted by pharmacokinetic modeling and simulation and later confirmed by clinical studies. The pharmacokinetics of etanercept in patients with rheumatoid arthritis are comparable to those in healthy individuals and patients with ankylosing spondylitis, congestive heart failure, and psoriasis. In children with polyarticular-course juvenile rheumatoid arthritis, after subcutaneous doses of 0.4 mg/kg twice weekly, the clearance of etanercept may be slightly reduced in children aged 4 to 8 years. Pharmacokinetic simulation predicts that a dose of 0.8 mg/kg once weekly generates comparable systemic exposure as 0.4 mg/kg twice weekly. No requirement for etanercept dosage adjustment is needed when etanercept is coadministered with warfarin, digoxin, or methotrexate.     

Etanercept: a review of its use in the management of ankylosing spondylitis and psoriatic arthritis

Etanercept (Enbrel), a recombinant, dimeric, soluble tumour necrosis factor (TNF) receptor protein, is approved in various countries for the treatment of adult patients with ankylosing spondylitis or psoriatic arthritis.Monotherapy with subcutaneous etanercept 25mg twice weekly or 50mg once weekly was effective and generally well tolerated in patients with ankylosing spondylitis or psoriatic arthritis participating in several large, well designed clinical studies. Treatment with etanercept was more effective than placebo in reducing disease activity and improving health-related quality of life (HR-QOL) in both patient populations, and in delaying structural disease progression in patients with psoriatic arthritis. The beneficial response to etanercept achieved with shorter-term treatment was sustained in studies of up to 4 years' total duration. Randomised, well designed, head-to-head comparisons, including pharmacoeconomic analyses, with other anti-TNF biological modulators are required to accurately position etanercept and fully establish its cost effectiveness. In the meantime, etanercept is a valuable treatment option for patients with ankylosing spondylitis or psoriatic arthritis who are suitable candidates for therapy.     

Etanercept: long-term clinical experience in rheumatoid arthritis and other arthritis

Etanercept is a dimeric fusion protein based on the p75 TNF-alpha receptor. It binds to TNF-alpha and blocks its biologic activity. In randomized, double-blind, placebo-controlled trials, etanercept has therapeutic activity in rheumatoid arthritis, psoriatic arthritis, polyarticular-course juvenile idiopathic arthritis and ankylosing spondylitis. Etanercept improves joint inflammation, physical function and slows/halts structural damage, especially when combined with methotrexate. A sustained response is observed in a substantial percentage of patients. Although some safety issues should be considered before starting etanercept treatment, in general terms, etanercept is a well tolerated drug with an acceptable safety profile. The use of any TNF-alpha antagonist must be in agreement with the National Recommendations for Biologic Therapy, and in difficult clinical situations, a balance between risk/benefit needs to be obtained.     

Etanercept for psoriasis: two case reports

Psoriasis is a chronic inflammatory skin disorder. Recent advances in the understanding of its immunological basis have led to its redefinition as being T-cell mediated. New biological agents have been developed as effective selective target therapies and promise to be an alternative to conventional systemic medications. Etanercept is a recombinant human protein recently approved for psoriatic arthritis treatment that has activity against tumor necrosis factor-alpha (TNF-alpha). It is composed of the human TNF receptor linked to the Fc portion of human IgG1. TNF-alpha seems to play a key role in the pathogenesis of psoriasis and psoriatic arthritis. Therefore, etanercept TNF antagonism is an effective approach for severe psoriasis. We describe two case reports of severe recalcitrant psoriasis, also with arthritis, that showed a remarkable improvement with etanercept, with no adverse events.     

Etanercept: long-term clinical experience in rheumatoid arthritis and other arthritis

Etanercept is a dimeric fusion protein based on the p75 TNF-α receptor. It binds to TNF-α and blocks its biologic activity. In randomized, double-blind, placebo-controlled trials, etanercept has therapeutic activity in rheumatoid arthritis, psoriatic arthritis, polyarticular-course juvenile idiophatic arthritis and ankylosing spondylitis. Etanercept improves joint inflammation, physical function and slows/halts structural damage, especially when combined with methotrexate. A sustained response is observed in a substantial percentage of patients. Although some safety issues should be considered before starting etanercept treatment, in general terms, etanercept is a well tolerated drug with an acceptable safety profile. The use of any TNF-α antagonist must be in agreement with the National Recommendations for Biologic Therapy, and in difficult clinical situations, a balance between risk/benefit needs to be obtained.