Therapy for rheumatoid arthritis: combinations of disease-modifying drugs and new paradigms of treatment

The use of antimalarials in combination with other disease modifying agents in rheumatoid arthritis–the French Experience

A significant proportion of patients with rheumatoid arthritis have an aggressive, severe disease that may contribute to excess mortality. It has been suggested that early, aggressive therapy might improve the prognosis of these patients with active, severe rheumatoid arthritis. Combinations of disease modifying anti-rheumatic drugs including antimalarials are increasingly used in patients with active disease. While several open trials showed encouraging results, some controlled studies gave less support for the use of combination therapy. Ongoing controlled trials of double or triple combination therapy, such as hydroxychloroquine, methotrexate and sulphasalazine, should help define its place in treating patients with rheumatoid arthritis.

Cell-surface and cytokine biomarkers in autoimmune and inflammatory diseases

Increasing emphasis is being placed on biomarkers as indicators of disease states in patients with autoimmune and inflammatory disorders, such as rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus. Careful description of the expression of cell-surface markers and cytokines produced by T and B lymphocytes can lead to a more complete characterization of disease activity in patient populations, and serve as an indicator of the patient's response to therapy.

Leflunomide: mode of action in the treatment of rheumatoid arthritis

Leflunomide is a selective inhibitor of de novo pyrimidine synthesis. In phase II and III clinical trials of active rheumatoid arthritis, leflunomide was shown to improve primary and secondary outcome measures with a satisfactory safety profile. The active metabolite of leflunomide, A77 1726, at low, therapeutically applicable doses, reversibly inhibits dihydroorotate dehydrogenase (DHODH), the rate limiting step in the de novo synthesis of pyrimidines. Unlike other cells, activated lymphocytes expand their pyrimidine pool by approximately eightfold during proliferation; purine pools are increased only twofold. To meet this demand, lymphocytes must use both salvage and de novo synthesis pathways. Thus the inhibition of DHODH by A77 1726 prevents lymphocytes from accumulating sufficient pyrimidines to support DNA synthesis. At higher doses, A77 1726 inhibits tyrosine kinases responsible for early T cell and B cell signalling in the G(0)/G(1) phase of the cell cycle. Because the immunoregulatory effects of A77 1726 occur at doses that inhibit DHODH but not tyrosine kinases, the interruption of de novo pyrimidine synthesis may be the primary mode of action. Recent evidence suggests that the observed anti-inflammatory effects of A77 1726 may relate to its ability to suppress interleukin 1 and tumour necrosis factor alpha selectively over their inhibitors in T lymphocyte/monocyte contact activation. A77 1726 has also been shown to suppress the activation of nuclear factor kappaB, a potent mediator of inflammation when stimulated by inflammatory agents. Continuing research indicates that A77 1726 may downregulate the glycosylation of adhesion molecules, effectively reducing cell-cell contact activation during inflammation.

Minocycline for the treatment of rheumatoid arthritis

The scientific basis for the use of antibiotics (with special emphasis on tetracycline and its derivatives) in the treatment of RA is discussed. The data on efficacy and toxicity are presented. The possible place of tetracycline derivatives within the overall strategy of RA treatment is also presented.

Methotrexate in rheumatoid arthritis: an update with focus on mechanisms involved in toxicity

OBJECTIVES

To provide an update of the current knowledge of the mechanism of action of low-dose methotrexate (MTX) in the treatment of patients with rheumatoid arthritis (RA), with an emphasis on the mechanisms involved in toxicity. We also considered strategies currently used to prevent or decrease toxicity of MTX.

METHODS

We reviewed the literature dealing with the subjects of MTX treatment of RA, the mechanisms of action of low-dose MTX regarding efficacy and toxicity, and strategies used to prevent or decrease MTX toxicity.

RESULTS

MTX is a fast working and effective second-line antirheumatic agent (SLA). Its use is limited mainly because of side effects. The mechanisms of action regarding efficacy and toxicity are probably determined by different metabolic pathways. Recent data indicate that the antiinflammatory effect of MTX is mediated by adenosine. However, MTX side effects can only partly be explained by folate antagonism and may also depend on its action on other related metabolic pathways. The latter include the homocysteine-methionine-polyamine pathway and purine metabolism. Variants in these metabolic routes (ie, the C677T mutation in the methylene-tetrahydrofolate reductase [MTHFR] gene), may predispose to the development of side effects. Currently the most promising strategy to decrease or prevent toxicity of MTX is concomitant prescription of folic acid or folinic acid. Other strategies are currently under investigation.

CONCLUSIONS

MTX benefits a majority of RA patients. Approximately 30% of patients, however, abandon treatment because of drug-related side effects. Folic acid or folinic acid likely reduces MTX toxicity. More data, however, are needed to evaluate a potential detrimental effect on the antirheumatic efficacy of MTX.

Antibody to stratum corneum (antikeratin antibody) and antiperinuclear factor: markers for progressive rheumatoid arthritis

The purpose of this study was to examine the relationship between circulating antibodies to stratum corneum (AKA) and antiperinuclear factors (APF) on one hand, and the x-ray progression of joint damage in chronic poly/oligoarthritis on the other hand. The analysis involved 133 patients with either rheumatoid or nonspecific arthritis derived from a cohort of 442 patients with recent onset arthritis. The patients were followed up for eight years with regular clinical, laboratory, and radiological evaluations. Radiographic evidence of joint destruction was quantitated by a radiographic index based on the Larsen grading. AKA and APF were detected, either at entry or at follow-up, in 26 and 54 patients, respectively. Seventy-six of the 133 patients had developed erosions. All AKA-positive patients had a rheumatoid factor-positive erosive poly-arthritis. The presence of APF was also associated with a progressive arthritis although four APF-positive patients had a non-erosive disease. Neither AKA nor APF were able to distinguish a particularly severe form of progressive RA.

Combination of second-line antirheumatic drugs

Single drug therapy is often not satisfactory in the treatment of chronic arthritis. The combination of second-line antirheumatic drugs is therefore increasingly employed. Various strategies of combining drugs can be used, starting with combinations or adding agents in case of insufficient effect of single therapy. Effective combinations have to be found empirically because lack of knowledge about pharmacodynamics and pharmacokinetics often hinders rational choices. Few controlled studies on combinations of second-line antirheumatic drugs exist, results suggesting very moderately increased efficacy and increased toxicity. Recently, results of combinations, mainly with methotrexate, have become available. Combining this agent with azathioprine did not offer advantages. Cyclosporin added to insufficiently effective methotrexate possibly has some value and antimalarials combined with methotrexate may be beneficial regarding effectivity and/or toxicity. Methotrexate added to insufficiently effective sulphasalazine seems to be better than methotrexate alone, although this combination when used from the start of the therapy was disappointing. Triple therapy of the latter combination together with hydroxychloroquine turned out to be superior to single methotrexate and to the combination of sulphasalazine and hydroxychloroquine. Surprisingly, the toxicity of these combinations was mainly comparable to single therapy. In conclusion, combinations of second-line antirheumatic drugs have a role, although not yet clearly defined, in the therapy of chronic arthritis.

Acute febrile toxic reaction in patients with refractory rheumatoid arthritis who are receiving combined therapy with methotrexate and azathioprine

OBJECTIVE

To assess the frequency and clinical features of an acute febrile toxic reaction (AFTR) in patients with refractory rheumatoid arthritis (RA) receiving combined therapy with methotrexate (MTX) and azathioprine (AZA).

METHODS

A cohort of 43 RA patients being treated with MTX/AZA combination therapy were studied. In all of them, RA had been refractory to single-therapy disease-modifying antirheumatic drugs. We analyzed the frequency and clinical features of AFTR, which consisted mainly of the development of fever, leukocytosis, and cutaneous leukocytoclastic vasculitis when AZA was added to the MTX regimen.

RESULTS

Four of the 43 patients (9.3%) who had been receiving long-term, well-tolerated treatment with MTX (mean +/- SD 375.5 +/- 159.5 days, range 227-561 days) developed AFTR shortly (mean +/- SD 25.7 +/- 13.6 days, range 17-46 days) after the addition of AZA to the regimen. The AFTR resolved rapidly (3 +/- 1.4 days) after discontinuation of AZA and MTX. In 2 cases, rechallenge with AZA and MTX was linked to a new flare of AFTR.

CONCLUSION

The knowledge of this side effect is particularly important because it mimics a severe infectious complication related to immunosuppressive therapy, and because rechallenge can produce severe toxicity. Most of the new combined therapies for RA do not seem to be more toxic than single-drug treatment. Nevertheless, clinicians should be aware of a possible increase in side effects due to drug interactions or some other unidentified mechanism.

The use of antimalarials in combination with other disease modifying agents in RA – the British experience

Antimalarial drugs are effective disease modifying agents in RA with a low incidence of serious toxic effects. Recently, combinations of second-line agents have been used in RA in attempts to treat patients with no response to a number of single agents, or suboptimal response to a single agent.

Combinations of drugs have been selected for maximum efficacy and minimum toxicity, but clinical trials are difficult to design and interpret. In particular, ensuring adequate power to detect small differences in response poses a major problem. Antimalarials are an attractive choice for combination therapy due to their efficacy, mechanisms of action and toxicity profile.

In this review, the evidence for the use of antimalarials in combination in RA is examined. No advantage has been shown in combining antimalarials with gold, penicillamine or sulphasalazine compared with monotherapeutic regimens. There is some evidence to suggest a beneficial combination of antimalarials with methotrexate, but this is as yet inconclusive. Open non-randomised uncontrolled studies have shown that antimalarials combined with cytotoxic agents are effective but highly toxic.

The authors conclude that there is little good evidence to support the introduction of combination second-line drug therapy for RA into widespread therapeutic use.

Reduction in long-term disability in patients with rheumatoid arthritis by disease-modifying antirheumatic drug-based treatment strategies

OBJECTIVE

Therapeutic strategies for rheumatoid arthritis (RA) have been evolving from the traditional "pyramid" approach toward one based upon early and sustained use of disease-modifying antirheumatic drugs (DMARDs), in the hope of improving long-term health outcomes. However, few data to have been presented to document the effects of this approach. We sought to directly assess associations between consistent DMARD use and long-term functional outcomes.

METHODS

We studied 2,888 RA patients who were followed up prospectively for up to 20 years (average 9 years) at 8 databank centers. The independent variable was the proportion of patient encounters that resulted in treatment with > or = 1 DMARD (hydroxychloroquine, sulfasalazine, auranofin, intramuscular gold, D-penicillamine, methotrexate, and/or azathioprine). The dependent variable was each patient's last recorded Disability Index value from the Health Assessment Questionnaire (HAQ).

RESULTS

Increased DMARD use was strongly associated with better long-term Disability Index values (P < 0.0001). The association was strengthened when restricted to more seriously affected (rheumatoid factor (RF)-positive) patients. The magnitude of the effect, unadjusted, was a difference of 0.53 HAQ Disability units (scale 0-3) between 100% DMARD use and 0%. Correlation coefficients ranged up to 0.26. Effects were similar for all disease duration periods (0-4, 5-9, 10-14, 15-19, and 20+ years). "Control" correlations, with variables computed to represent the proportion of time in which patients were taking either nonsteroidal anti-inflammatory drugs or prednisone, failed to show positive associations. A multiple linear regression model, which controlled for age, disease duration, sex, RF positivity, proportion of visits under a prednisone regimen, and initial disability level, included the proportion of time in which patients were taking DMARDs (P < 0.0001), with a model R2 of 0.54. These results were obtained despite an adverse selection bias in which more severely affected individuals were given DMARDS more frequently, and despite absence of data on drug use early in the disease course of many patients. Thus, these results, which suggest up to a 30 percent reduction in long term disability with consistent DMARD use, are most likely conservative.

CONCLUSION

An association between consistent DMARD use and improvement in long-term functional outcomes in RA is supported by these data.

Combination therapy of cyclosporine A with methotrexate or hydroxychloroquine in refractory rheumatoid arthritis

We evaluated the efficacy and toxicity of cyclosporine A (CsA) in combination with methotrexate (MTX) or hydroxychloroquine (HCQ) in patients with refractory rheumatoid arthritis (RA). Fourteen patients with active RA who had failed to respond adequately to injectable MTX and 14 who had failed to respond to oral HCQ had CsA added to their regimens for 6 months. Adverse effects were monitored every 2 weeks for 2 months, and monthly thereafter; outcome parameters were assessed at 0, 3, and 6 months. The starting dose of CsA was 2.5 mg/kg/day in both groups. Twenty-four patients (12 in each group) completed the 6-month study. All clinical variables (except grip strength in the HCQ + CsA group) significantly improved with both treatment regimens. Global efficacy was evaluated by means of the composite Chronic Arthritis Systemic Index. Fifteen patients (9 in the MTX + CsA and 6 in the HCQ + CsA group) could be considered responders, and 9 non-responders. The final mean daily dose of CsA was 3.3 +/- 0.8 mg/kg in the HCQ + CsA group and 3.1 +/- 0.9 mg/kg in the MTX + CsA group. Mild adverse events were more frequently observed in the MTX-CsA than in HCQ + CsA-treated patients (33 events in 11 patients as against 20 in nine). In combination with HCQ or MTX, CsA, over a 6 month period, may improve efficacy in patients with refractory RA without any significant increase in toxicity; MTX + CsA seems to be slightly more efficacious and more toxic than HCQ + CsA. Larger prospective controlled trials are necessary to define the efficacy of these combinations.

Comparison of azathioprine, methotrexate, and the combination of the two in the treatment of rheumatoid arthritis. A forty-eight-week controlled clinical trial with radiologic outcome assessment

OBJECTIVE

To assess the relative efficacy of methotrexate (MTX), azathioprine (AZA), and their combination in the treatment of rheumatoid arthritis (RA) in a double-blind, prospective, multicenter, controlled trial.

METHODS

Two hundred nine patients with active RA were treated with escalating doses of MTX (5-15 mg/week), AZA (50-150 mg/day), or combination (5mg MTX/week plus 50 mg AZA/day-7.5 mg MTX/week plus 100 mg AZA/day), with opportunity to increase the dosage at 6-week intervals. The patients were evaluated for significant clinical and laboratory improvement and assessed for radiologic progression at 48 weeks.

RESULTS

One hundred ten patients remained on the initial, randomly assigned therapeutic regimen. The percentage of patients who were responders, defined as those who had 30% or greater improvement in at least 3 of 4 variables, was 38% for the combination treatment, 26% for AZA, and 45% for MTX (P = 0.06). A trend toward decreased radiologic progression was seen in the MTX-treated patients. Termination of treatment due to adverse experience occurred more frequently with combination and AZA treatments than with MTX treatment. Lack of effectiveness, adverse gastrointestinal effects, and liver enzyme elevation were the most frequent causes of treatment discontinuation.

CONCLUSION

This study establishes that the combination of MTX and AZA in the dosages utilized is not associated with more toxicity than treatment with single agents; however, enhanced efficacy is also not seen. There is a trend toward decreased radiologic progression in patients treated with MTX.

Advances and issues in the pharmacotherapy of rheumatoid arthritis

Rheumatoid arthritis (RA) is an unremitting and progressive disease despite the use of second-line drugs in the majority of patients. In addition, a shortened life-span directly attributable to RA is now recognized. The additions of methotrexate and sulfasalazine to the therapeutic armamentarium represent important treatment advances during the past decade. To improve the effectiveness of second-line drug therapy, earlier intervention and use of these newer drugs in combination with older second-line drugs is being advocated. Several proposed strategies for intervening earlier, combining second-line drugs, and/or improving patient selection for second-line drug therapy are reviewed. Systematic evaluation of these strategies is needed. Controlled studies to date have not demonstrated combining second-line drugs is superior to using individual second-line agents. Future advances in optimizing patient outcomes with these drugs will require systematic screening for potentially superior treatment strategies followed by supportive proof of effectiveness in the form of large-scale studies.

A risk-benefit assessment of slow-acting antirheumatic drugs in rheumatoid arthritis

There is no ideal slow-acting antirheumatic drug. Therapy of rheumatoid arthritis (RA) is currently being modified, with strong recommendations to abandon the traditional pyramidal approach. The call is for a more aggressive, earlier approach to suppress inflammation. Combination therapy rather than the use of a single agent is advocated by some. Improved methods for assessing disease activity as well as measurement of outcome have been developed. Markers of poor prognosis have helped to define patients for earlier treatment. Comparison of toxicity among such a diverse group of drugs is probably best achieved with a toxicity index measuring the number of episodes expressed in terms of patient-years of exposure. Toxicity remains the commonest reason for discontinuing an agent, while remission beyond 36 months on therapy is uncommon, except with methotrexate. The profile of toxicity is clearly defined for individual agents, but combination therapy may reveal an entirely different set of toxic manifestations. There is an urgent need to develop a set of risk factors to predict toxicity in an individual patient. Juvenile chronic arthritis behaves differently from adult RA. Drug toxicity profiles are similar, but less common. Outcome is more difficult to measure, with the major impact of disease and therapy being on growth retardation.

Therapeutic progress. I: Current treatment of rheumatoid arthritis

Over recent years the pharmacological treatment strategy for rheumatoid arthritis (RA) has changed. An early, aggressive approach has been adopted with a view to maintaining functional capacity. The changing role of nonsteroidal anti-inflammatory agents is discussed in the light of the potential toxicity of this class of drugs. The current use of second-line agents is dealt with in depth and includes guidelines to patient monitoring. Particular attention has been paid to the growing use of cyclosporin A in the treatment of RA as this drug represents the newest, most potent, nonexperimental form of treatment. The questions of when to introduce second-line agents, who should receive treatment and how many drugs should be prescribed are all addressed in this review. The relative efficacy and toxicity of these agents is discussed and a treatment protocol is proposed.

Rheumatoid arthritis

Preview Once considered relatively benign, rheumatoid arthritis is now recognized as a disabling systemic disease that causes substantial morbidity and mortality. Early, aggressive therapy may be critical for altering the course of disease. Drs Vikings-son and Graziano describe the causes and clinical course of rheumatoid arthritis and discuss diagnostic considerations and prognostic indicators that support optimum management.

Early, aggressive therapy for rheumatoid arthritis: concerns, descriptions, and estimate of outcome

The past few years have witnessed changing perceptions about rheumatoid arthritis (RA); it is now considered a serious systemic disease that confers not only physical and social morbidity but also earlier mortality. The long-term outcome of sequential monotherapy based on the therapeutic pyramid has been disappointing. A review of prognostic factors, acute disease activity measures, functional measures, and the results of preliminary trials with combination therapy suggests that specific goals of treatment can be established and that logical, aggressive treatment in early disease can be accomplished. These goals should include prompt control and continuous reduction of the active joint count to < or = 4 and normalization of acute-phase reactants. The "graduated-step paradigm" of treatment designed with these goals in mind is described, and a retrospective series that gives an estimate of outcome with its use is reported.

Disease modification in rheumatoid arthritis with special reference to cyclosporin A

Disease modifying antirheumatic drugs improve clinical markers of synovial inflammation as well as acute phase reactants and functional status in patients with rheumatoid arthritis. Some of the disease modifying antirheumatic drugs probably also retard radiographic progression. Data from prospective observational studies and epidemiological studies indicate a modest and temporary effect. New treatment modalities are needed, including both new strategies and new drugs. Cyclosporin A improves clinical markers of synovial inflammation and is useful for individual patients with rheumatoid arthritis. However, further studies are required to investigate the long term efficacy and tolerance of cyclosporin in rheumatoid arthritis.