Concomitant leflunomide therapy in patients with active rheumatoid arthritis despite stable doses of methotrexate. A randomized, double-blind, placebo-controlled trial

Anti-inflammatory effects of leflunomide in combination with methotrexate on co-culture of T lymphocytes and synovial macrophages from rheumatoid arthritis patients

OBJECTIVES

To investigate the anti-inflammatory effects of the active leflunomide metabolite A771726 (Lef-M) in combination with methotrexate (MTX) on synovial macrophages (SM) from rheumatoid arthritis (RA) patients co-cultured with an activated T cell line (Jurkat cell line).

METHODS

Pro-inflammatory cytokines (TNFalpha, IL1beta, IL6), adhesion molecule ICAM-1, cyclooxygenase isoenzymes (COX1, COX2), and the nuclear factor kappaB (NF-kappaB) complex were analysed on SM co-cultured with a T cell line, as intracellular protein expression by immunocytochemistry (ICC) and western blot analysis, as extracellular protein expression by ELISA assay, and as mRNA expression by reverse transcriptase-multiplex PCR (RT-MPCR) after treatment with Lef-M (1, 10, 30 micromol/l) alone or in combination with MTX (50 ng/ml).

RESULTS

The most significant intracellular decrease in cytokines was observed by ICC in SM treated with the combination of Lef-M (1, 10, 30 micromol/l) and MTX (50 ng/ml) versus untreated SM (TNFalpha 29%, 37%, 49%, IL1beta 56%, 43%, 50%, and IL6 59%, 62%, 71%, respectively). Furthermore, a significant decrease was confirmed concerning cytokine levels evaluated by ELISA in the medium of SM treated with the combination Lef-M+MTX (TNFalpha 40%, 41%, 44%; IL1beta 10%, 20%, 60%; IL6 37%, 41%, 49%, respectively). Western blot and RT-PCR analysis confirmed these results. Concordant decreased expression was observed for ICAM-1, COX1, COX2, and the NF-kappaB complex after Lef-M+MTX treatment.

CONCLUSIONS

The combination of MTX and Lef-M shows additive inhibitory effects on the production of inflammatory mediators from SM co-cultured with a T cell line. These observations might support the positive results obtained in RA clinical studies by combination therapy.

Rheumatic disease in the elderly: rheumatoid arthritis

This review summarizes the different aspects of rheumatoid arthritis and the spectrum of diseases that can present as rheumatoid arthritis-like arthritis in the elderly population. With the aging of Western population, different forms of inflammatory arthritis' prevalence and incidence are increasing in the elderly persons. Difficulties in establishing the diagnosis and introducing new treatment modalities in this patient group poses a great challenge for the clinicians. The management of inflammatory arthritis in the elderly requires special consideration in regard to the comorbidities and increased frequency of adverse events. There is definitely a substantial need for improving different aspects of diagnostic and therapeutic interventions that will reduce the impact of inflammatory arthritis in the growing elderly population.

Low-dose methotrexate: a mainstay in the treatment of rheumatoid arthritis

Methotrexate administered weekly in low doses is a mainstay in the therapy of rheumatoid arthritis. Although originally developed as a folate antagonist for the treatment of cancer, its mechanism of action in the therapy of rheumatoid arthritis remains less clear. Several mechanisms have been proposed including inhibition of T cell proliferation via its effects on purine and pyrimidine metabolism, inhibition of transmethylation reactions required for the prevention of T cell cytotoxicity, interference with glutathione metabolism leading to alterations in recruitment of monocytes and other cells to the inflamed joint, and promotion of the release of the endogenous anti-inflammatory mediator adenosine. These mechanisms of action and the role of methotrexate in the suppression of rheumatoid arthritis are reviewed.

A meta-analysis of the efficacy and toxicity of combining disease-modifying anti-rheumatic drugs in rheumatoid arthritis based on patient withdrawal

INTRODUCTION

Combinations of disease-modifying anti-rheumatic drugs (DMARDs) are increasingly used to treat rheumatoid arthritis (RA). Early trials showed their toxicity while recent trials suggest superior efficacy. Trials of DMARD combinations have enrolled different types of patient (early or established RA), used different designs (step-up, parallel or step-down) and utilized a range of outcome measures. We undertook a systematic review of combination DMARD therapy for RA and carried out a meta-analysis to evaluate the evidence for efficacy and toxicity.

METHOD

Medline, PubMed and EmBase were searched using MESH headlines 'arthritis, rheumatoid', 'drug therapy, combination' and 'randomized controlled trial' (RCT) for papers published from 1975 to April 2004. References from published articles were also searched. Three independent assessors evaluated abstracts and selected trials for detailed examination. Trials were excluded if their quality was poor, were not published in English or studied DMARDs not licensed to treat RA. Two independent assessors extracted data. Efficacy was assessed by the numbers of patients withdrawn due to lack of efficacy. Toxicity was assessed by the numbers of patients withdrawn due to adverse events. Risk ratios (RR) with 95% confidence intervals (CI) were calculated and meta-analysis was carried out based on a random effects model. Sensitivity analyses evaluated different treatment combinations, trial designs, study populations and outcome measures.

RESULTS

Fifty-three potentially relevant RCTs were identified. Twelve were excluded due to: using unlicensed DMARDs (n = 3); reporting in journal supplements of RCTs already included (n = 2); follow-up of an earlier RCT, report of biological outcomes or pharmacokinetics (n = 5); and non-English language publications (n = 2). Forty-one RCTs were evaluated in detail and another five excluded (three open-labelled studies and two with high patient attrition); 36 studies were included in the meta-analysis. These comprised 13 step-up, 16 parallel and 7 step-down trials. Nine assessed early RA and 27 established RA. Seven added steroids to DMARD monotherapy and one study added steroids to DMARD combinations. Six assessed methotrexate (MTX) plus tumour necrosis factor (TNF) inhibitors. Overall, combination DMARD therapy was more effective than monotherapy (RR 0.35; 95% CI 0.28, 0.45) although the risk of toxicity was also slightly higher (RR 1.37; 95% CI 1.16, 1.62). Combinations of MTX with TNF inhibitors and MTX with sulphasalazine or anti-malarials showed good efficacy/toxicity ratios.

CONCLUSIONS

DMARD combinations vary in their efficacy/toxicity ratio. MTX plus sulphasalazine and/or anti-malarials and MTX plus TNF inhibitors have particularly favourable benefit/risk ratios.

Duration of rheumatoid arthritis influences the degree of functional improvement in clinical trials

BACKGROUND

Functional capacity is an important outcome in rheumatoid arthritis and is generally measured using the Health Assessment Questionnaire disability index (HAQ). Functional limitation incorporates both activity and damage. Because irreversible damage increases over time, the HAQ may be less likely to show improvement in late than in early rheumatoid arthritis.

OBJECTIVE

To determine the relation between sensitivity to change of the HAQ and duration of rheumatoid arthritis in reports of clinical trials.

METHODS

Data were pooled from clinical trials that measured responses of HAQ scores at three or six months. The effect size of the HAQ was calculated and linear regression used to predict the effect size by duration of rheumatoid arthritis at group level. Treatment effect was adjusted for by including the effect sizes of pain scores and of tender joint counts as additional independent variables in separate models. Subgroup analysis employed contemporary regimens (methotrexate, leflunomide, combination therapies, and TNF inhibitors) only.

RESULTS

36 studies with 64 active treatment arms and 7628 patients (disease duration 2.5 months to 12.2 years) were included. The effect sizes of the HAQ decreased by 0.02 for each additional year of mean disease duration using all trials, and by 0.04/year in the subgroup analysis (p<or=0.01 for both analyses, except for pain adjusted models at three months).

CONCLUSIONS

In individual trials, less improvement in the HAQ might be expected in late than in early rheumatoid arthritis. Comparison of changes in HAQ among rheumatoid arthritis trials should take into consideration the disease stage of the treated groups.

Efficacy, tolerability and cost effectiveness of disease-modifying antirheumatic drugs and biologic agents in rheumatoid arthritis

Over the last decade, several new drugs have become available for the treatment of patients with rheumatoid arthritis. These agents include the new disease-modifying antirheumatic drug (DMARD) leflunomide and the biologic agents, tumor necrosis factor (TNF)-alpha antagonists and an interleukin (IL)-1 receptor antagonist. Methotrexate is commonly used as the first DMARD, has a well documented clinical efficacy and slows radiological deterioration. Sulfasalazine appears to have similar properties, albeit to a lesser extent. Leflunomide has similar efficacy as methotrexate but it is less tolerated than sulfasalazine. The adverse effect profiles of these three drugs makes regular laboratory monitoring mandatory. Several combination therapies with DMARDs were proven to be more effective than mono-DMARD therapy. However, until now these strategies have not been widely adopted. TNF antagonists are potent anti-inflammatory drugs, with a rapid onset of effects compared with traditional DMARDs. The IL-1 receptor antagonist, anakinra, has an intermediate place between methotrexate and the TNF antagonists with respect to efficacy. The adverse effects of TNF antagonists include an increased incidence of common and opportunistic infections. Thus far, anakinra has not been associated with an enhanced rate of opportunistic infections. Some of the biologic agents have been associated with worsening heart failure and demyelinating disease. The limited long-term safety data of the biologic agents are a point of concern because, at present, an enhanced risk for malignancies, particularly lymphoma, can not be excluded. Drug costs of traditional DMARDs are up to US dollars 3000 per year, whereas for the biologics the yearly drug costs range between US dollars 16,000 and > US dollars 20,000. Cost-effectiveness analyses are necessary to determine whether or not these high costs are justified. Unfortunately, adequate, prospective, economic evaluations are not yet available. Until these become available, treatment decisions will be based on the balance of direct costs and indirect costs and expected cost savings in the future.

Unmet needs in rheumatoid arthritis

Until the pathophysiology/etiology of rheumatoid arthritis (RA) is better understood, treatment strategies must focus on disease management. Early diagnosis and treatment with disease-modifying antirheumatic drugs (DMARDs) are necessary to reduce early joint damage, functional loss, and mortality. Several clinical trials have now clearly shown that administering appropriate DMARDs early yields better therapeutic outcomes. However, RA is a heterogeneous disease in which responses to treatment vary considerably for any given patient. Thus, choosing which patients receive combination DMARDs, and which combinations, remains one of our major challenges in treating RA patients. In many well controlled clinical trials methotrexate and other DMARDs, including the tumor necrosis factor-α inhibitors, have shown considerable efficacy in controlling the inflammatory process, but many patients continue to have active disease. Optimizing clinical response requires the use of a full spectrum of clinical agents with different therapeutic targets. Newer therapies, such as rituximab, that specifically target B cells have emerged as viable treatment options for patients with RA.

New therapies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease, which continues to cause significant morbidity in affected persons. In the past few years, a number of new exciting therapeutic options have become available. These reflect the application of knowledge obtained from advancements in understanding of disease pathogenesis and underlying molecular mechanisms. A number of these therapies are outlined in the following review, including the various biological modifiers, in particular, anti-tumour necrosis factor-alpha agents and interleukin-1 (IL-1) receptor antagonists, which have been developed in recognition of the role of pro-inflammatory cytokines in RA. Also notable, is the current interest centring on the development and trials with B cell depletion therapies, specifically rituximab, in patients with RA. This demonstrates acknowledgment for a more significant role for B cells in the aetiology of RA, in contrast to the long held view that RA was a predominantly T cell mediated disease. To evaluate this therapeutic option for RA, salient features from recent rituximab trials have been collated. Finally, a selection of other therapeutic alternatives, including anti-IL-6 receptor monoclonal antibody and tacrolimus, and newer anti-rheumatic therapies presently in development are summarized.

Combination treatment strategies in early rheumatoid arthritis

Combinations of disease modifying antirheumatic drugs (DMARDs) are increasingly being used in patients with early rheumatoid arthritis (RA) when long term results with sequential DMARD monotherapy are disappointing. Combination DMARD therapy may be more effective than monotherapy, and has no additional short term adverse events. The evidence for using combination DMARD therapy is still weak, however, and further trials are needed.

Treatment continuation in patients receiving biological agents or conventional DMARD therapy

OBJECTIVE

To compare drug continuation rates in patients with rheumatoid arthritis who start on a biological agent and in a control group of patients with a change in disease modifying antirheumatic drug (DMARD) treatment after previous DMARD failure.

METHODS

Patients with rheumatoid arthritis enrolled in the German biologics register between May 2001 and September 2003 were included in the study. Data were available for 511 patients treated with etanercept, 343 with infliximab, 70 with anakinra, and 599 controls. Propensity scores were used to select a subsample of patients from the control group who were likely to be treated with biological agents because of their disease severity, as well as comparable infliximab and etanercept cases.

RESULTS

Treatment continuation after 12 months was similar for etanercept (68.6% (95% confidence interval, 62% to 75%)) and infliximab (65.4% (58% to 73%)) but lower for anakinra (59% (41% to 77%)). Treatment continuation was more likely for patients on combinations of biological agents and DMARDs than for those on infliximab or etanercept alone. Patients treated with biological agents were more severely ill than those in the control group and had more previous DMARD failures. After adjustment for baseline differences, the continuation rates were higher in patients treated with biological agents than in comparable control patients treated with leflunomide or leflunomide/methotrexate.

CONCLUSIONS

Treatment continuation of biological agents in clinical practice is less likely than in randomised clinical trials but more likely than in comparable controls treated with conventional DMARDs.

Clinical trials in rheumatic diseases: designs and limitations

Randomized controlled clinical trials provide the best method to distinguish a drug from placebo without the inevitable selection biases that are seen in standard clinical care. This article reviews designs and limitations of clinical trials that are used in rheumatic diseases. The primary design in clinical trials is a parallel, in which patients are randomized in parallel to different therapies at different dosages or placebo. In recent years, other designs have been used increasingly, including "step-up," "step-down," and "cross-over" designs. Limitations of clinical trials in chronic diseases include a short time frame versus the long duration of disease, inclusion and exclusion criteria, use of surrogate markers that may not represent clinically relevant markers, statistical significance does not necessarily indicate clinical significance necessarily, and the fact that a control group does not assure the absence of bias. Therefore, long-term databases are needed to supplement clinical trials in analyzing results of therapy for rheumatoid arthritis.

Leflunomide in rheumatoid arthritis: recommendations through a process of consensus

OBJECTIVES

To determine, by consensus, the optimal use of leflunomide in rheumatoid arthritis (RA), using a multidisciplinary panel of experts and performing meta-analyses of available data.

METHODS

A multidisciplinary panel of experts in RA was convened. Important questions, pertinent to the use of leflunomide in the treatment of RA, were defined by consensus at an initial meeting. Each question was allocated to subgroups of two or three members, who worked separately to prepare a balanced opinion, based on published literature, data from individual patients taking part in phase II and phase III clinical trials provided by Aventis, and data from a USA-based medical claims database (AETNA). The full group then reconvened to agree on an overall consensus statement. Recommendations concerning efficacy and tolerability versus comparator drugs and placebo were derived from two new meta-analyses.

RESULTS

Leflunomide was at least as effective as sulphasalazine and methotrexate, and equally well tolerated on meta-analysis of trial data. Overall withdrawal rates for all adverse events were similar for all three drugs. Avoidance of the loading dose reduces 'nuisance' side-effects (e.g. nausea), but probably delays the onset of action. Adverse events could usually be managed by dose reduction and/or symptomatic therapy.

CONCLUSIONS

On the basis of efficacy, safety and cost, leflunomide should be considered in patients with RA who have failed first-line DMARD drug therapy. In refractory cases, leflunomide may be used in combination with, for example, methotrexate before biological agents. Therapy should be initiated by a specialist, but repeat prescribing in general practice on a shared care basis is acceptable using agreed protocols. Clear mechanisms are required to monitor toxicity, with good communication between the patient and rheumatologist to manage nuisance side-effects and avoid unnecessary discontinuation of leflunomide.

Management Issues with Elderly-Onset Rheumatoid Arthritis

Elderly-onset rheumatoid arthritis (EORA) is defined as rheumatoid arthritis (RA) starting at >60 years of age. EORA is characterised by a lower female/male ratio compared with RA in younger patients and it more frequently has an acute onset accompanied by constitutional symptoms. Two incompletely overlapping subsets of RA have been recognised: one exhibits the classical RA clinical picture while the other has a polymyalgia rheumatica-like appearance, characterised by shoulder involvement, absence of rheumatoid factor and, usually, by a nonerosive course. Identification of anti-cyclic citrullinated peptide antibodies is useful for distinguishing the latter subset from true polymyalgia rheumatica. Elderly-onset spondyloarthritis, crystal-related arthritis, remitting seronegative symmetrical synovitis with pitting oedema syndrome and hepatitis C virus-related arthritis must also be considered in the differential diagnosis. EORA treatment requires prudence because of the increase in age-related risks pertaining principally to the renal, cardiovascular and gastrointestinal systems. No groups of molecules usually employed for RA therapy in younger subjects (analgesics, NSAIDs, corticosteroids, disease-modifying antirheumatic drugs, anticytokine drugs) can be excluded a priori from the treatment of EORA patients. Nevertheless, the risk/benefit ratio relating to their use must be accurately evaluated for every single patient. Recently marketed compounds such as leflunomide and tumour necrosis factor-alpha antagonists have also increased the therapeutic opportunities for aged RA patients.

Leflunomide inhibits transendothelial migration of peripheral blood mononuclear cells

OBJECTIVES

To test whether the active metabolite of leflunomide (LEF-M), in addition to blocking the proliferation of activated lymphocytes by inhibiting dihydro-orotate dehydrogenase (DHODH), influences the transendothelial migration (TEM) of peripheral blood mononuclear cells (PBMC).

METHODS

In an in vitro model of PBMC transmigration through an endothelial cell (EC) barrier, PBMC were re-collected in three groups: cells not adherent to the EC, cells bound to, and cells which had migrated through, the EC layer. Experiments in which cells were pretreated with LEF-M (in the absence or in the presence of uridine) were compared with parallel experiments in the presence of medium alone.

RESULTS

Preincubation of EC with LEF-M led to a 36 (SEM 16)% reduction in PBMC TEM (p<0.05). Likewise, preincubation of PBMC induced a reduction in their TEM of 39 (9)% (p<0.005). Incubation of both PBMC and EC with LEF-M had an additive effect (mean reduction of 48 (6)%, p<0.005). Incubation of PBMC with LEF-M also decreased monocytic CD44 expression (p<0.005) and PBMC-hyaluronan binding (p<0.05). Incubation of cells with LEF-M and uridine in addition to LEF-M reversed the inhibition of migration, suggesting that the observed effects were due to DHODH inhibition. Fluorocytometric analysis of PBMC subsets within the migrated population showed a decrease of monocytes, but not of B or T cells, after LEF-M treatment.

CONCLUSIONS

LEF-M reduces monocytic adhesion molecule expression and TEM and may thus interfere with monocyte and EC activities in RA. Thus, the clinical effects of leflunomide may, at least in part, be due to blocking cell traffic into the inflamed synovia.

The broadening use of leflunomide in clinical practice

Autoimmune diseases make up a large proportion of chronic disease care. Inducing remission by immunosuppression remains the cornerstone of long-term management. This article reviews the place of leflunomide in clinical practice and outlines its potential applications beyond its licenced indication, rheumatoid arthritis.

The effect of folic acid and folinic acid supplements on purine metabolism in methotrexate-treated rheumatoid arthritis

OBJECTIVE

To determine if folinic acid supplementation during methotrexate (MTX) therapy for rheumatoid arthritis (RA) reduces both urinary 5-aminoimidazole-4-carboxamide (AICA) and urinary adenosine excretion more than does folic acid supplementation. AICA and adenosine are markers for MTX interference with purine metabolism.

METHODS

Forty patients with RA who received MTX for 6 weeks were randomized to receive either daily folic acid or folinic acid supplements during an additional week of MTX therapy. Colorimetric and radioimmunocompetition assays were used to measure 24-hour urinary AICA and adenosine excretion levels, respectively.

RESULTS

At the end of 6 weeks, 24-hour urinary levels of AICA, but not adenosine, were elevated as compared with baseline levels (i.e., prior to MTX therapy). Folinic acid, but not folic acid, supplementation normalized urinary AICA levels during MTX therapy. Relatively high urinary levels of AICA were correlated with reduced disease activity. No similar correlations were seen with urinary adenosine levels.

CONCLUSION

The blockade of purine nucleotide biosynthesis by MTX at the AICA ribonucleotide transformylase-catalyzed step may be related to the efficacy of MTX, and this blockade is effectively relieved by folinic acid, but not by folic acid, supplementation.

Debilitating diarrhoea and weight loss due to colitis in two RA patients treated with leflunomide

Diarrhoea and weight loss are frequently reported adverse events in rheumatoid arthritis (RA) patients receiving the disease-modifying antirheumatic drug (DMARD) leflunomide. According to the available literature these side effects occur mostly during the first 6 months of treatment, are rather mild and rarely lead to treatment withdrawal. In this report, we describe the clinical, endoscopic and histologic findings in two RA patients with severe diarrhoea and important weight loss more than 12 months after starting treatment with leflunomide. In both cases the symptoms were caused by colitis, but one had ulcerative and the other microscopic colitis. Despite treatment with budesonide the complaints only improved after withdrawal of leflunomide, making a causal relationship between this drug and the pathogenesis of colitis probable. The heterogeneous histopathological findings in these two patients, however, do not allow us to draw any definitive conclusions about the mechanism by which leflunomide causes diarrhoea and weight loss in RA patients. We conclude that persistent diarrhoea or weight loss in patients taking leflunomide can be more serious than what is previously reported in the literature. In such cases leflunomide treatment should be stopped and an endoscopic examination of the colon is recommended. Given the long half-life of this drug a washout procedure with cholestyramine should be considered whenever the problem is severe or persistent.

Leflunomide in active rheumatoid arthritis: a prospective study in daily practice

AIMS

We prospectively studied the efficacy, incidence of adverse drug reactions and withdrawal from leflunomide in an outpatient population with rheumatoid arthritis in a setting of care-as-usual.

METHODS

In this prospective case series study, a standard dataset was collected from outpatient medical records, including patient and disease characteristics, data on leflunomide use and adverse drug reactions.

RESULTS

During the study period 136 rheumatoid arthritis patients started leflunomide. Median (range) follow-up duration was 317 (11-911) days. Sixty-five percent of patients experienced at least one adverse drug reaction related to leflunomide. During follow-up 76 patients (56%) withdrew from leflunomide treatment, mainly because of adverse drug reactions (29%) or lack of efficacy (13%). The overall incidence density for withdrawal from leflunomide was 56.2 per 100 patient years. Complete data for calculating efficacy using a validated disease activity score on 28 joints (DAS(28)) was available for 48, 36, and 35% of patients at 2, 6, and 12 months follow-up, respectively. Within a 12-month period after start of leflunomide treatment 76% of the evaluable patients were classified as moderate or good responders according to the DAS(28) response criteria.

CONCLUSIONS

In the setting of care-as-usual rheumatoid arthritis patients starting leflunomide frequently experienced adverse drug reactions. More than half of the patients withdrew from leflunomide treatment within 1 year of starting leflunomide treatment, mainly because of adverse drug reactions.

Leflunomide in active rheumatoid arthritis: a prospective study in daily practice

AIMS

We prospectively studied the efficacy, incidence of adverse drug reactions and withdrawal from leflunomide in an outpatient population with rheumatoid arthritis in a setting of care-as-usual.

METHODS

In this prospective case series study, from outpatient medical records a standard dataset was collected including patient and disease characteristics, data on leflunomide use and adverse drug reactions.

RESULTS

During the study period 136 rheumatoid arthritis patients started leflunomide. Median (range) follow-up duration was 317 (11-911) days. Sixty-five percent of patients experienced at least one adverse drug reaction related to leflunomide. During follow-up 76 patients (56%) withdrew from leflunomide treatment, mainly because of adverse drug reactions (29%) or lack of efficacy (13%). The overall incidence density for withdrawal from leflunomide was 56.2 per 100 patient-years. Complete data for calculating efficacy using a validated disease activity score on 28 joints (DAS(28)) was available for 48, 36, and 35% of patients at 2, 6, and 12 months follow-up, respectively. Within a 12-month period after start of leflunomide treatment 76% of the evaluable patients were classified as moderate or good responders according to the DAS(28) response criteria.

CONCLUSIONS

In the setting of care-as-usual, rheumatoid arthritis patients starting leflunomide frequently experienced adverse drug reactions. More than half of the patients withdrew from leflunomide treatment within a year after start of leflunomide treatment, mainly because of adverse drug reactions.

Leflunomide for the treatment of rheumatoid arthritis in clinical practice: incidence and severity of hepatotoxicity

OBJECTIVE

Leflunomide is a novel disease modifying antirheumatic drug (DMARD). Because of reports on possible hepatotoxicity and adaptations in the recommendations for monitoring liver function during leflunomide treatment, we conducted a study to evaluate the incidence and severity of hepatotoxicity.

METHODS

We included consecutive rheumatoid arthritis patients starting treatment with leflunomide in the region of Friesland (The Netherlands) between January 2000 and January 2002. During follow-up patient characteristics, disease characteristics, and clinical and laboratory data on liver functions were registered. Severity of hepatotoxicity was categorised using the National Cancer Institute Common Toxicity Criteria, as moderate (grade 2), severe (grade 3) or life threatening (grade 4).

RESULTS

One hundred and one patients were followed for a median period of 10 months (range 0.5-12). Grade 2 or 3 elevations in any liver function blood test were recorded in a total of nine patients (8.9%). No grade 4 elevations were recorded. Four patients (4%) showed grade 2-3 aminotransferase elevations. Due to grade 2 hepatotoxicity one patient (1%) was withdrawn from leflunomide treatment, and one patient continued leflunomide at a reduced dose. In eight of nine patients with grade 2-3 liver function blood tests, these elevated liver function tests occurred within 6 months after starting leflunomide. None of the patients with grade 2 or 3 toxicity had a history of hepatic disease, eight patients concomitantly used potential hepatotoxic co-medication. Eight (8%) patients used leflunomide in combination with methotrexate, and one of these patients developed hepatotoxicity. No clinical signs of serious hepatotoxicity were recorded during follow-up.

DISCUSSION

In 8.9% of the patients, grade 2 or 3 hepatotoxicity was recorded within the first year after the start of leflunomide therapy based on liver enzyme determinations. In the majority of the patients liver enzyme elevations occurred within the first 6 months of therapy and resolved during continued follow-up. None of the patients showed clinical signs of hepatotoxicity.

CONCLUSION

Under continued monitoring of liver functions hepatotoxicity during leflunomide use does not seem to be a major problem in our population.

The use of methotrexate in rheumatoid arthritis

OBJECTIVE

To address the long-term efficacy and toxicity issues related to methotrexate (MTX) and compare it with other disease-modifying antirheumatic drugs (DMARDs).

METHODS

Review of the international literature on the clinical use of MTX in rheumatoid arthritis (RA) disease.

RESULTS

MTX has emerged as a relatively safe and effective treatment for RA that compares favorably with other therapies, particularly because of its considerably longer median drug survival. The toxicity profile of MTX is well established and includes serious and sometimes fatal liver disease, pneumonitis, and cytopenias. Hence, regular and careful monitoring of patients taking MTX is essential, particularly when MTX is combined with other DMARDs. Folate supplementation can reduce some of the most common side effects of MTX, but it has not yet been established whether this translates into a reduced risk of serious disease. Another potential approach to reducing the toxicity of MTX is therapeutic drug monitoring and dose individualization. However, correlations between pharmacokinetics and clinical response have been addressed in only a few studies and with conflicting results.

CONCLUSIONS

MTX is an effective DMARD with a relatively safe profile compared with other therapies. Folate supplementation can significantly reduce the risk of MTX toxicity. Finally, it is essential that patients be monitored carefully to reduce the potential serious toxicities of MTX.

[Internist's therapy of rheumatoid arthritis]

Rheumatoid arthritis is the most common inflammatory joint disease and is characterized by chronic, symmetric, erosive synovitis of small joints of hands and feet. Prevalence in women is threefold higher than in man. Structural damage of the joints starts between the first and second year of the disease. Early therapeutic interventions can alter the course of rheumatoid arthritis by delaying the progression of radiographic joint destruction, which correlates with the grade of disability. Approval of new biologic antirheumatic drugs in the last few years improved the outcome of rheumatoid arthritis.

When a DMARD fails, should patients switch to sulfasalazine or add sulfasalazine to continuing leflunomide?

OBJECTIVE

To evaluate the efficacy and safety of adding sulfasalazine to leflunomide treatment compared with switching to sulfasalazine alone in patients with RA with an inadequate response to leflunomide monotherapy.

METHODS

Patients with active RA ((DAS28) >3.2) who were enrolled in the first open label phase of the RELIEF study received leflunomide for 24 weeks. Inadequate responders then entered the double blind phase and received a further 24 weeks' treatment with leflunomide (20 mg once daily) plus sulfasalazine (final dose 2 g once daily), or placebo plus sulfasalazine (dose as above). The primary efficacy variable was the DAS28 response rate, and secondary efficacy outcomes were ACR 20%, 50%, and 70% response rates. Adverse events, including standard laboratory tests, were recorded.

RESULTS

106 inadequate responders entered the double blind phase; 56 received leflunomide plus sulfasalazine, and 50 placebo plus sulfasalazine. In the intention to treat population, more patients receiving leflunomide plus sulfasalazine (25/56 (45%)) achieved a DAS28 response than those receiving placebo plus sulfasalazine (17/50 (34%)) (p = 0.179). In week 24 completers, more patients receiving leflunomide plus sulfasalazine (17/56 (30%)) were DAS28 responders than those receiving placebo plus sulfasalazine (10/50 (20%)) (p = 0.081). Comparable numbers in each group were ACR 20% responders; the ACR 50% response rate was significantly higher in the leflunomide plus sulfasalazine group (8.9%) than in the placebo plus sulfasalazine group (0%) (p = 0.038). The safety profiles of both groups were comparable.

CONCLUSION

Patient numbers are small and firm conclusions cannot be reached, but a non-significant benefit is indicated for combining leflunomide with sulfasalazine compared with switching to sulfasalazine alone in patients inadequately responding to leflunomide.

Leflunomide-Associated Pancytopenia With or Without Methotrexate

OBJECTIVE:

To report 18 cases of pancytopenia associated with leflunomide use in Australia, 5 of which were treated at Princess Alexandra Hospital, Brisbane.

CASE SUMMARIES:

Leflunomide was used in the treatment of rheumatoid arthritis in 17 of 18 patients; the other patient was diagnosed with systemic lupus erythematosus. Median age was 65.5 years (range 18–79), and 15 of the patients were female. Fourteen patients were on combined treatment with methotrexate. Pancytopenia was typically severe, requiring hospital admission, withdrawal of the immunosuppressant(s), intensive supportive therapy, and treatment of neutropenic sepsis. Five patients died, 4 of whom were receiving concomitant methotrexate. Time to onset of pancytopenia ranged from 11 days to 4 years (median 4 mo). In one case in which the patient had been stable while receiving leflunomide, methotrexate, and hydroxychloroquine for 4 years, fatal pancytopenia was triggered by acute renal failure secondary to dehydration and use of nonsteroidal antiinflammatory drugs. The Naranjo probability scale suggested a probable causal association in 5 cases and possible association in the remainder.

DISCUSSION:

Leflunomide, indicated for treatment of active rheumatoid arthritis, inhibits pyrimidine synthesis in lymphocytes and other rapidly dividing cells and may rarely be associated with life-threatening pancytopenia. Combination therapy with methotrexate may increase the risk. Time to onset is variable, and clinicians should remain vigilant, particularly when there is a change in the patient's baseline health status.

CONCLUSIONS:

The risk of pancytopenia during leflunomide therapy appears to be increased when the drug is combined with methotrexate and in older patients. Onset may be delayed, and ongoing monitoring of blood counts is essential.

T-cell-activation inhibitors in rheumatoid arthritis

As rheumatoid arthritis (RA) is a chronic inflammatory disabling disease and a cure is not available, optimisation of therapeutic strategies is mandatory. Within recent years many new details of the inflammatory cascade(s) have been elaborated, leading to new therapeutic options such as neutralisation of tumour necrosis factor-alpha (TNFalpha). T-cell inhibition is another new approach to the treatment of RA. However, it is important to note two points: first, the role of T lymphocytes in the initiation and/or perpetuation of RA is still debated controversially. Second, there are few truly T-cell-specific agents that have proven to be effective and are established in the treatment of inflammatory disorders. Leflunomide may be considered one such agent; another in development is the fusion protein CTLA4-Ig. From a clinical perspective, studies demonstrating efficacy of these agents might represent the strongest support for a role of T cells in RA. In addition to leflunomide and CTLA4-Ig, therapeutic agents with activity against T cells, including anti-CD4 antibodies, cyclosporin, tacrolimus and T-cell receptor (TCR)-Vbeta-chain vaccination strategies, have been studied in patients with RA. Combination therapies including any of these T-cell-activation inhibitors with non-T-cell-specific agents such as methotrexate, antimalarials or anti-TNFalpha biologicals may prove the most effective strategies in controlling this complex disease.

Safety overview of new disease-modifying antirheumatic drugs

Beginning in 1998, a surge of new agents has expanded treatment options for rheumatoid arthritis (RA) patients. Although the disease modifying potential of these agents is encouraging, their use must be weighed against an evolving array of new safety concerns. Because of the popularity of these agents with patients and rheumatologists alike, clinicians must be prepared to discuss the potential risks associated with novel disease-modifying antirheumatic drugs and biologic therapies as they begin to appear with greater frequency in practice. This article discusses the safety issues arising from clinical trial and postmarketing experience with several new and commonly used agents, with specific emphasis on adalimumab, etanercept, infliximab, anakinra, and leflunomide.

Leflunomide

Leflunomide is a low-molecular weight, synthetic, oral agent specifically developed for immunosuppression. Because of activity in animal models, leflunomide was tested in rheumatoid arthritis(RA). These investigations have demonstrated that leflunomide reduces the clinical symptoms and signs of RA, improves health related quality of life, and retards structural damage. Leflunomide has been evaluated in RA patients as monotherapy and in combination with methotrexate. Close monitoring for adverse events with particular attention for monitoring liver enzymes for hepatic toxicity is important during treatment with leflunomide.

Patient-reported outcomes better discriminate active treatment from placebo in randomized controlled trials in rheumatoid arthritis

BACKGROUND

Recent randomized controlled trials (RCTs) in rheumatoid arthritis (RA) have used patient- and physician-reported outcomes, ESR and/or CRP as components of ACR response criteria to assess efficacy.

OBJECTIVES

Mean changes from baseline in patient- and physician-reported outcome measures, ESR and CRP were compared in two RCTs in patients with active RA. Comparisons between active and placebo treatment used mean percentage improvements and standard effect sizes (SESs).

RESULTS

In both protocols, patient-reported assessments of disease activity, pain and physical function reflected little or no improvement with placebo, best discriminating between active and placebo therapy, as did ESR and CRP.

CONCLUSION

Improvements in signs and symptoms of active RA in placebo RCTs appear to be best reflected by patient-reported measures of physical function, as long as reported changes in global assessments of disease activity and/or pain reflect similar benefit. Patient-reported outcome measures should be considered objective; treatment-associated changes are congruent with measures of inflammation, and appear less susceptible to the placebo response.

Dose escalation of parenteral methotrexate in active rheumatoid arthritis that has been unresponsive to conventional doses of methotrexate: a randomized, controlled trial

OBJECTIVE

To examine whether dose escalation of intramuscular (IM) methotrexate (MTX) up to 45 mg/week improves disease control in patients who have active rheumatoid arthritis (RA) despite receiving conventional doses (15 mg/week) of IM MTX, and to obtain preliminary data on patient tolerability and adverse effects of higher doses of IM MTX.

METHODS

Patients >18 years of age who had active RA, defined as a European League Against Rheumatism (EULAR) Disease Activity Score in 28 joints (DAS28) of >3.2, and who had received 15-20 mg/week of oral MTX for at least 2 months were switched (week 0) to 15 mg/week of IM MTX for 6 weeks. Patients whose DAS28 remained >3.2 at both week 4 and week 6 were randomized, in a double-blind manner, either to continue to receive 15 mg/week IM MTX with monthly placebo escalation or to receive escalating doses of IM MTX monthly up to 45 mg/week. The dose of MTX or placebo was escalated every 4 weeks if the DAS28 was >2.5. Safety assessments and determination of the DAS28 were performed every 2 weeks and monthly, respectively. Disease activity parameters from the American College of Rheumatology (ACR) core disease activity set and health status as recorded on the Medical Outcomes Study Short-Form 12 were determined at baseline (week 0) and final assessment (week 22). The primary outcome was the percentage of patients in each group achieving a target DAS28 of <3.2. Secondary outcomes comprised the percentage of patients whose DAS28 improved by >1.2, the percentage of patients achieving a 20% improvement in the ACR core disease activity measures (ACR20), and the percentage of patients achieving a good response, a moderate response, or no response in accordance with the EULAR response criteria.

RESULTS

Sixty-four patients were eligible for entry and were switched from oral MTX to 15 mg/week IM MTX. At baseline, the mean +/- SD DAS28 was 5.6 +/- 0.88; after 6 weeks of IM MTX, the DAS28 had improved by a mean of 0.42 (95% confidence interval [95% CI] 0.15-0.69). At 6 weeks, 54 patients still had a DAS28 of >3.2 and were therefore eligible for randomization. By 22 weeks, 1 patient (3.7%) in each group achieved the primary outcome of a DAS28 <3.2 (95% CI for the difference between the groups -15% to +15%). Five patients (18.5%) in each group showed an improvement of >1.2 in the DAS28 (95% CI for the difference between the groups -18% to +18%). One patient (3.7%) in each group achieved an ACR20 response, but none achieved a good response as defined by the EULAR response criteria. One patient in each group had a serious adverse reaction; minor adverse reactions were more frequently reported in the dose escalation group.

CONCLUSION

Switching from oral to parenteral MTX 15 mg/week results in a minor improvement in disease control. For patients with active RA receiving 15 mg/week IM MTX, increasing the dose up to 45 mg/week does not improve disease control. Higher doses of IM MTX were generally well tolerated and not associated with an increase in serious adverse reactions to the drug.

Tacrolimus in rheumatoid arthritis patients receiving concomitant methotrexate

OBJECTIVE

To assess the safety of tacrolimus used in combination with oral methotrexate (MTX) to control the signs and symptoms of rheumatoid arthritis (RA) in patients whose disease remains active despite treatment with MTX.

METHODS

This was a multicenter open-label study conducted at 13 US sites. Eighty patients who at baseline had active RA (mean tender/painful joint count 29.4, mean swollen joint count 17.4, mean erythrocyte sedimentation rate 25.1 mm/hour) despite treatment for >/=1 month with a stable, maximally tolerated dosage of oral MTX (</=20 mg/week, median dosage 15 mg/week, range 5-20 mg/week) were enrolled and received 3 mg/day tacrolimus as a single oral dose once per day for 6 months while continuing to receive MTX at the existing stable dosage. All other disease-modifying antirheumatic drugs were discontinued; stable dosage of nonsteroidal antiinflammatory drugs and oral corticosteroids (</=10 mg/day prednisone or its equivalent) were allowed. All 80 patients received at least one dose of the study drug and were included in the primary safety and efficacy analyses. Seventy-five patients had at least one postbaseline efficacy assessment, and 63 patients (78.8%) completed the study. The primary clinical response criterion was the American College of Rheumatology definition of 20% improvement (ACR20) at the end of treatment.

RESULTS

Seven patients (12.5%) withdrew from the study because of adverse events possibly or probably related to treatment with tacrolimus, and 4 (5.0%) withdrew due to lack of efficacy. One serious adverse event (pancreatitis) was possibly related to tacrolimus treatment. The mean (+/-SD) creatinine (Cr) level increased from 0.74 +/- 0.16 mg/dl at baseline to 0.81 +/- 0.22 mg/dl (P < 0.001) at the end of treatment. Twenty-three patients (28.8%) had a >/=30% maximum increase in the Cr level from baseline during the study, with the Cr level in 3 patients (3.8%) exceeding the range considered normal for their age and sex. The maximum Cr level during the study was 1.8 mg/dl. The ACR20 clinical response rate at the end of treatment was 52.5% (95% confidence interval 41.6-63.4%).

CONCLUSION

In patients whose active RA persists despite treatment with MTX, tacrolimus in combination with MTX is safe and well-tolerated and provides clinical benefit.

Pharmacological treatment of established rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory condition of unknown aetiology that affects about 1% of the general population. Although the optimal care of RA patients requires various modalities, pharmacotherapy remains the cornerstone of treatment for established RA. The current therapeutic model encourages a step-up approach that safely incorporates several currently available classes of agents: non-steroidal anti-inflammatory drugs, selective cyclo-oxygenase-2 inhibitors, glucocorticoids, disease-modifying anti-rheumatic drugs, and biological agents (tumour necrosis factor-alpha inhibitors and interleukin-1 receptor antagonist). Non-steroidal anti-inflammatory drugs, selective cyclo-oxygenase-2 inhibitors and glucocorticoids, which offer a quick onset of symptom relief, are used mainly as adjunctive therapies. Disease-modifying anti-rheumatic drugs and biologicals have been successful in altering disease outcome and slowing radiographic progression. The indications, efficacy and safety of these agents in clinical trials and practice are reviewed in this chapter.

Therapeutic strategies for rheumatoid arthritis

Recent years have seen considerable advances in our understanding of both the clinical and basic-research aspects of rheumatoid arthritis. Clinical progress has come from a better recognition of the natural history of the disease, the development and validation of outcome measures for clinical trials and, consequently, innovative trial designs. In parallel, basic research has provided clues to the pathogenic events underlying rheumatoid arthritis, and advances in biotechnology have facilitated the development of new classes of therapeutics. Here, we summarize the fruits of these advances: innovative approaches to the use of existing, traditional disease-modifying antirheumatic drugs; novel agents approved very recently; and further avenues that are presently under investigation or which are of more distant promise.

The efficacy and safety of leflunomide in patients with active rheumatoid arthritis: a five-year followup study

OBJECTIVE

To investigate the efficacy and safety of leflunomide beyond 2 years in a multinational, open-label extension of 2 phase III double-blind studies.

METHODS

Patients with rheumatoid arthritis (RA) who received leflunomide (100 mg/day for 3 days, 10 mg/day or 20 mg/day thereafter) in the 2 phase III studies and who completed 2 years of treatment were offered inclusion in the open-label extension phase and were maintained on the same dosage of leflunomide. The American College of Rheumatology revised criteria for 20% improvement (ACR20), ACR50, and ACR70 response rates, the Stanford Health Assessment Questionnaire (HAQ) scores, and C-reactive protein (CRP) levels were assessed. Safety measures included monitoring of adverse events and laboratory values.

RESULTS

A total of 214 patients (mean age 57 years) were treated with leflunomide for >2 years; 74.8% of the patients were female. The mean disease duration was 4.1 years (range 0.1-26.6 years), and in 44% of patients, RA was first diagnosed within 2 years of entry into the phase III studies. The mean duration of leflunomide treatment was 4.6 years (range 2.8-5.8 years), and 32% of patients had received no previous treatment with disease-modifying antirheumatic drugs. ACR20, ACR50, and ACR70 response rates and HAQ scores at 1 year were maintained through year 4 or until the end point. No new types of adverse events were observed, and liver function was normal at baseline and at the end point in the majority of patients.

CONCLUSION

The improvements in both functional ability and physician-based efficacy measures seen with leflunomide after 1 year were maintained for up to 5 years (maximum treatment duration 5.8 years), demonstrating that the early efficacy of leflunomide in patients with RA is sustained long-term, and that the long-term safety profile of leflunomide is no different from that observed in phase III trials.

Drug-induced liver disease

The year 2002 saw a warning from the US Food and Drug Administration not to use the diet agent, Lipokinetix, and brought to light a few new agents as potential hepatotoxins. Numerous other reports confirmed the hepatotoxicity of several previously described agents. Refinements in causality assessment remain an important aspect in defining drug-induced liver disease and proposed new upper limits of normal for alanine aminotransferase that are lower than most laboratories currently report may require rethinking our definition of "normal liver function tests." Chronic viral hepatitis B and C remain important risk factors for antiretroviral-induced liver injury in patients co-infected with the human immunodeficiency virus and in patients receiving antituberculosis therapy. Acetaminophen retains its status as the most common cause of acute drug-induced liver failure in the United States and in many other countries. Several papers addressed the issue of accidental versus intentional overdoses, the role of alcohol consumption as a risk factor, and newer aspects of treating and preventing acetaminophen injury to the liver. Finally, the use of potentially hepatotoxic medications in patients with underlying liver disease continues to be a controversial topic and a rational approach to the use of such drugs in this setting is provided.

Leflunomide for treating rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease. Leflunomide, as an inhibitor of pyrimidine synthesis, has a different mechanism of action than other existing disease modifying anti-rheumatic drugs (DMARD).

OBJECTIVES

To determine the efficacy and toxicity of leflunomide compared to placebo or other DMARDs in the treatment of RA.

SEARCH STRATEGY

We conducted a search in MEDLINE, EMBASE, Current Contents and the Cochrane Controlled Trial Register for trials up to December 2001. We also hand-searched reference lists and consulted content experts.

SELECTION CRITERIA

Two independent reviewers selected the trials that met predetermined inclusion criteria.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data and assessed methodologic quality using standardized forms.

MAIN RESULTS

Six trials were included in this review. Using the ACR20 improvement criteria, there was an absolute difference in improvement of 28% (95% confidence interval: 21 - 35%) favouring leflunomide (232 out of 413 leflunomide treated patients compared to 89 out of 311 placebo patients met the criteria). There was no difference in ACR20 response rate between the patients treated with leflunomide and SSZ or MTX at 6 and 12 months. Other clinical outcomes were improved significantly in the leflunomide group compared to placebo but not different from SSZ or MTX. Withdrawals due to adverse events with leflunomide were 10% greater than placebo (70 out of 416 compared to 18 out of 311 respectively). Important adverse events included gastrointestinal symptoms, elevated liver function tests, alopecia, and infections. Overall adverse events and withdrawals in the leflunomide group were not significantly different from SSZ or MTX.

REVIEWER'S CONCLUSIONS

Leflunomide appears to improve all clinical outcomes and delay radiologic progression at both 6 and 12 months of treatment compared to placebo. Its efficacy and adverse events at 2 years of treatment are comparable to SSZ and MTX. Long-term efficacy and toxicity remains to be established.