Survival and effectiveness of leflunomide compared with methotrexate and sulfasalazine in rheumatoid arthritis: a matched observational study

Development of a population pharmacokinetic model and optimal dosing regimen of leflunomide in Korean population

PURPOSE

Leflunomide is an immunosuppressive drug indicated for the treatment of rheumatoid arthritis (RA). While the pharmacokinetics (PK) of its active metabolite A771726 reportedly show large interindividual variability, no efficient dose individualization strategy is currently available. The goal of this work was to develop a population PK model for A771726 and propose an optimal individualized dosing strategy.

METHODS

A771726 plasma concentration data were collected from 50 healthy male volunteers participating in two leflunomide PK studies given a single oral dose of 40 mg. Concentrations were elevated in low body weight (WT) subjects and showed multiple peaks. Thus, A771726 PK modeling was conducted incorporating allometry scaling and enterohepatic circulation (EHC). For dose optimization, simulating a set of 1000 virtual subjects from the developed model and dividing the subjects into 5 groups with WT of 50, 60, 70, 80, 90 kg, respectively, the optimal dose was explored that achieves the drug concentration most similar to the target, which was defined as the concentration for the 70 kg subject treated with the current standard dosage regimen (the loading dose of 100 mg QD for 3 days, followed by the maintenance dose of 20 mg QD).

RESULTS

The data were best described by a two compartment model with first order absorption incorporating EHC with the bile released into the intestine. None of the covariates tested was found to be significant other than WT used in allometry. Simulation showed that the optimal loading dose increased by 15 mg for every 10 kg increment in WT while the optimal maintenance dose was 15 and 25 mg for 50 and 90 kg groups, respectively, and the same (= 20 mg) for the others. Large concentration differences from the target observed in low and high WT groups disappeared when optimal doses were given.

CONCLUSIONS

This work demonstrates the importance of a population PK model-based dose optimization approach in maintaining drug therapeutic concentrations in leflunomide treatment.

Risk of Liver Fibrosis in Methotrexate-Treated Patients: A Systematic Review

Methotrexate (MTX), an antifolate agent, is recommended as the first-line disease-modifying antirheumatic drug (DMARD). In this systematic review, our goals were to assess liver fibrosis in methotrexate-treated patients, evaluate liver fibrosis in relation to treatment duration and cumulative dose, and identify differences based on the underlying disease. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to perform the systematic review. We thoroughly searched PubMed, PubMed Central (PMC), and Cochrane library databases to identify relevant articles based on predefined selection criteria. Studies were selected based on the following predefined eligibility criteria: English language, papers from the last 20 years, systematic reviews, observational studies, randomized controlled trials (RCTs), and clinical trials, which included papers on MTX playing roles in the development of liver fibrosis with the derived data transferred to a template. Following that, quality was assessed using the appropriate assessment tool for each study. The initial search yielded 512 results. Following a thorough review, 10 studies were chosen for final consideration: eight observational studies and two systematic reviews. Liver enzyme (LE) elevations during MTX therapy are a common but transient problem. Serial abnormal LE tests may be associated with liver pathology, but fibrosis development is uncommon. However, it is unclear from the literature how therapy should be adjusted in the case of elevated LE and to what extent MTX is linked to liver toxicity; definitive conclusions cannot be drawn because more research is needed.

Unmet need for patient involvement in rheumatology registries and observational studies: a mixed methods study

Objective

The contribution of patient research partners (PRPs) is well established in EULAR recommendation development. However, in observational and registry studies, PRP involvement is not well-defined and remains limited.

Methods

Based on a round table discussion during the EULAR Registries and Observational Drug Studies (RODS) meeting in 2019, a mixed methods study was undertaken, including a survey to RODS participants and EULAR PRPs and focus groups with volunteers from the survey. An inductive thematic analysis approach was applied to qualitative data and descriptive statistics to survey data.

Results

We retrieved 45 survey responses and ran 3 focus groups with a total of 17 participants. The notion of PRP involvement in research was positively perceived by PRPs and the wider academic rheumatology community. There is universal agreement that PRP involvement in registry research is low and inclusion in different parts of the research cycle is limited. Potential benefits of PRP involvement include: input on the research objectives based on patients’ needs, advice and support regarding recruitment and retention strategies, obtaining patient views on analysis and interpretation, and assistance in disseminating results. Researchers and PRPs highlighted that education, inclusion of PRPs with diverse backgrounds and a welcoming environment as important facilitators for PRP involvement. On the other hand, preconceptions of researchers and insufficient budget allocation have been identified as barriers.

Conclusion

There is an unmet need to involve PRPs in registries and observational studies and to better define their required input during all research stages. This study provides suggestions for successful PRP integration.

Efficacy and safety of HLX01 in patients with moderate-to-severe rheumatoid arthritis despite methotrexate therapy: a phase 3 study

Background

To evaluate the efficacy and safety of HLX01, a rituximab biosimilar, as combination therapy with methotrexate in Chinese patients with active rheumatoid arthritis who had inadequate responses to methotrexate.

Methods

In this double-blind, placebo-controlled phase 3 trial, biologic-naïve patients with moderate-to-severe active rheumatoid arthritis and inadequate responses to methotrexate were randomized 2:1 to receive 1000 mg HLX01 or placebo intravenously on days 1 and 15. On the first day of weeks 24 and 26, patients in both groups received 1000 mg HLX01 via intravenous infusion. The primary endpoint was the American College of Rheumatology (ACR) 20 response rate at week 24. Secondary endpoints including efficacy, safety, immunogenicity, pharmacokinetics and pharmacodynamics were assessed up to week 48.

Results

Between 28 May 2018 and 11 September 2020, 275 patients were randomized to the HLX01 group (n = 183) or the placebo group (n = 92). At week 24, the proportion of patients achieving ACR20 response was significantly greater in the HLX01 group compared with the placebo group in the intention-to-treat population (60.7% vs 35.9%; P < 0.001) and per-protocol set (60.3% vs 37.1%; P < 0.001). Most secondary efficacy endpoints favoured HLX01 when assessed at weeks 12, 24, 36 and 48. Incidences of treatment-emergent adverse events were similar between groups. Infusion-related reactions occurred more frequently following the initial two doses of HLX01 than the subsequent doses.

Conclusions

HLX01 plus methotrexate improved clinical outcomes compared with placebo in Chinese patients with rheumatoid arthritis who had inadequate responses to methotrexate. This treatment regimen was well tolerated, showing comparable safety profiles to placebo.

Trial registration

ClinicalTrials.gov, NCT03522415. Registered on 11 May 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02821-x.

Granulocyte and monocyte/macrophage apheresis for the treatment of immune-mediated inflammatory arthropathies: case reports

Drug therapy of immune-mediated inflammatory arthropathies is not always satisfactory, and there is a risk of adverse events. Granulocyte and monocyte/macrophage apheresis (GMA) is a non-pharmacological therapeutic option that is beneficial and very well tolerated. GMA involves passing blood through a column with cellulose acetate beads to remove increased and activated myeloid lineage cells and improve the cytokine profile. The technique reduces pain and inflammation. We present four clinical reports that illustrate the clinical uses of GMA with the medical device Adacolumn^® in patients with different backgrounds and immune-mediated inflammatory arthritis. The results were positive, and no adverse events were reported.

Torque Teno Virus Quantification for Monitoring of Immunomodulation with Biological Compounds in the Treatment of Rheumatoid Arthritis

OBJECTIVES

Rheumatoid arthritis (RA) patients who fail to respond to methotrexate (MTX) can receive biologic disease-modifying antirheumatic drugs (bDMARDs). The Torque Teno Virus (TTV) is a potential novel candidate for monitoring of immunosuppression. We explore TTV in these patients and association with clinical response to bDMARDs.

METHODS

The BioBio Study is a multicentre randomized open-label trial, including RA patients with insufficient response to MTX. Patients were randomized to either TNFi (infliximab, INF), anti-IL-6 (tocilizumab, TCZ), CTLA4-Ig (abatacept, ABA) or anti-CD20 (rituximab, RTX) in addition to MTX. PCR was used to quantify TTV in the peripheral blood.

RESULTS

TTV was measured in 95 patients (INF, n = 23; TCZ, n = 22; ABA, n = 27; RTX; n = 23). TTV increased by a median of 4.5*104 copies/ml (c/ml; inter quartile range [IQR] 0-7.5*105) after 3 months. TTV levels at month 3 were associated with SDAI (p= 0.03) and CDAI response (p= 0.026) at month 6. A TTV cut-off level of 1.2*106 c/ml at month 3 had a positive likelihood ratio of 2.7 for prediction of SDAI85% response at month 6.

CONCLUSION

Our data suggest that TTV levels increase upon TNF, CD20 and co-stimulation blockade and associate with clinical response to bDMARDs in RA patients.

TRIAL REGISTRATION

ClinicalTrials.gov; https://clinicaltrials.gov; NCT01638715.

Conventional disease-modifying agents in rheumatoid arthritis - a review of their current use and role in treatment algorithms

Despite the development of targeted therapies, conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) remain the cornerstone of treatment of rheumatoid arthritis (RA). A literature search was conducted on treatment recommendations and relevant papers regarding new insights on therapeutics in rheumatoid arthritis. Methotrexate is considered the “anchor drug” due to its high efficacy as monotherapy and in combination with other conventional and targeted agents. Leflunomide and sulfasalazine are sound alternatives, whereas (hydroxy)chloroquine is primarily used in combination with other csDMARDs.

Their use is encouraged in all treatment phases – in combination with targeted agents, and with other csDMARDs. Combining different csDMARDs is especially attractive in lower income settings given the evidence proving (almost) equal efficacy and safety of the csDMARD combination approach compared to the combination of targeted agents with a csDMARD.

The aim of this review is to provide a clinically oriented insight into the pharmacology of each csDMARD and their place in treatment algorithms.

Methotrexate (MTX) Plus Hydroxychloroquine versus MTX Plus Leflunomide in Patients with MTX-Resistant Active Rheumatoid Arthritis: A 2-Year Cohort Study in Real World

Purpose

To compare the efficacy, safety, and cost-effectiveness of methotrexate (MTX) plus hydroxychloroquine (HCQ) vs MTX plus leflunomide (LEF) in established rheumatoid arthritis (RA) with inadequate response to MTX monotherapy in a real-world Chinese cohort.

Patients and Methods

A prospective RA cohort (n=549) was screened with eligible patients who had inadequate response (disease activity score in 28 joints using erythrocyte sedimentation rate, DAS28-ESR>3.2) to initial MTX monotherapy and subsequently received either MTX+HCQ or MTX+LEF. Propensity score matching (PSM) was applied to adjust the possible baseline confounders between two groups. The primary outcome was the proportion of patients achieving first remission (DAS28-ESR<2.6) during follow-up by log rank test. Secondary outcomes were changes of DAS28, glucocorticoids (GCs) exposure, safety, cost-effectiveness, sustained remission, and low disease activity (LDA) rate after 24-month follow-up.

Results

Overall, 222 eligible patients were subjected to the aforementioned two treatment protocols (MTX+HCQ, n=102; MTX+LEF, n=120). After PSM adjustment, 97 patients in each group were analyzed. A higher remission rate was observed in the MTX+HCQ group than in the MTX+LEF group (70.1% vs 56.7%, P=0.048). The median time to remission was 11 and 16 months in the two groups, respectively. At the endpoint, more patients achieved remission (46.8% vs 32.5%, P=0.063) and maintained sustained LDA in the HCQ group (53.2% vs 38.6%, P=0.062) and also more patients withdrew GCs in this group (32% vs 16.7%, P=0.053) than those in the LEF group. Safety profiles were non-alarming, with no significant difference between the two groups. The incremental cost-effectiveness ratio yielded by MTX+HCQ over MTX+LEF was $1,111.8 per quality-adjusted life-year (QALY), within the cost-effective threshold set as the per capita gross domestic product (GDP) of China.

Conclusion

The MTX+HCQ combination was seemingly superior to MTX+LEF in a real-world cohort of Chinese RA patients with inadequate response to methotrexate monotherapy in respect of the efficacy and cost-effectiveness.

CP-25, a compound derived from paeoniflorin: research advance on its pharmacological actions and mechanisms in the treatment of inflammation and immune diseases

Total glycoside of paeony (TGP) has been widely used to treat inflammation and immune diseases in China. Paeoniflorin (Pae) is the major active component of TGP. Although TGP has few adverse drug reactions, the slow onset and low bioavailability of Pae limit its clinical use. Enhanced efficacy without increased toxicity is pursued in developing new agents for inflammation and immune diseases. As a result, paeoniflorin-6'-O-benzene sulfonate (CP-25) derived from Pae, is developed in our group, and exhibits superior bioavailability and efficacy than Pae. Here we describe the development process and research advance on CP-25. The pharmacokinetic parameters of CP-25 and Pae were compared in vivo and in vitro. CP-25 was also compared with the first-line drugs methotrexate, leflunomide, and hydroxychloroquine in their efficacy and adverse effects in arthritis animal models and experimental Sjögren's syndrome. We summarize the regulatory effects of CP-25 on inflammation and immune-related cells, elucidate the possible mechanisms, and analyze the therapeutic prospects of CP-25 in inflammation and immune diseases, as well as the diseases related to its potential target G-protein-coupled receptor kinases 2 (GRK2). This review suggests that CP-25 is a promising agent in the treatment of inflammation and immune diseases, which requires extensive investigation in the future. Meanwhile, this review provides new ideas about the development of anti-inflammatory immune drugs.

Use of healthcare resources in a cohort of rheumatoid arthritis patients treated with biological disease-modifying antirheumatic drugs or tofacitinib

Introduction/objectives

The objective of this study is to describe the treatment patterns and use of healthcare resources in a cohort of Colombian patients with rheumatoid arthritis (RA) treated with biological disease-modifying antirheumatic drugs (bDMARDs) or tofacitinib.

Method

This is a descriptive study from a retrospective cohort of patients diagnosed with RA who were treated with bDMARDs or tofacitinib after failure of conventional DMARDs (cDMARDs) or first bDMARD. Patients who were receiving pharmacological treatment between 01 January 2014 and 30 June 2018 were included. The analysis is through the revision of claim database and electronical medical records. Demographic and clinical data were collected. The costs of healthcare resources were estimated from the billing expense of healthcare service provider.

Results

We evaluated 588 RA patients on treatment with bDMARDs (n = 505) or tofacitinib (n = 83), most of them were in combination with cDMARDs (85.4%). The 88.1% were females and mean age was 57.3 ± 12.5 years. The median evolution of RA since diagnosis was 9 years (IQR:4–17.2). The mean duration of use during follow-up of the bDMARDs or tofacitinib was similar, with a mean of 9.8 ± 1.9 months. It was identified that 394 (67.0%) discontinued therapy. The average annual direct cost of care per patient was USD 8997 ± 2172, where 97.2% was due to drug costs. The average annual cost of treatment per patient with bDMARDs was USD 8604 and tofacitinib was USD 6377.

Conclusions

In the face of a first failure of cDMARD, bDMARDs are frequently added. A high frequency of patients do not persist treatment during the first year of follow-up. The pharmacological treatment is the most representative cause of healthcare costs.

Key Points • Rheumatoid arthritis is a disease with a high burden of comorbidities, complications, and worse health-related quality of life and is associated with elevated healthcare costs. • The biological disease-modifying antirheumatic drugs or tofacitinib medications are indicated for those with significant progression of the disease and when there is a need for alternatives to achieve low levels of activity and remission. • Patients with rheumatoid arthritis treated with biological disease-modifying antirheumatic drugs or tofacitinib represent a significant economic burden to the health system, especially in the costs derived from pharmacological treatment.

EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update

OBJECTIVES

To provide an update of the European League Against Rheumatism (EULAR) rheumatoid arthritis (RA) management recommendations to account for the most recent developments in the field.

METHODS

An international task force considered new evidence supporting or contradicting previous recommendations and novel therapies and strategic insights based on two systematic literature searches on efficacy and safety of disease-modifying antirheumatic drugs (DMARDs) since the last update (2016) until 2019. A predefined voting process was applied, current levels of evidence and strengths of recommendation were assigned and participants ultimately voted independently on their level of agreement with each of the items.

RESULTS

The task force agreed on 5 overarching principles and 12 recommendations concerning use of conventional synthetic (cs) DMARDs (methotrexate (MTX), leflunomide, sulfasalazine); glucocorticoids (GCs); biological (b) DMARDs (tumour necrosis factor inhibitors (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab), abatacept, rituximab, tocilizumab, sarilumab and biosimilar (bs) DMARDs) and targeted synthetic (ts) DMARDs (the Janus kinase (JAK) inhibitors tofacitinib, baricitinib, filgotinib, upadacitinib). Guidance on monotherapy, combination therapy, treatment strategies (treat-to-target) and tapering on sustained clinical remission is provided. Cost and sequencing of b/tsDMARDs are addressed. Initially, MTX plus GCs and upon insufficient response to this therapy within 3 to 6 months, stratification according to risk factors is recommended. With poor prognostic factors (presence of autoantibodies, high disease activity, early erosions or failure of two csDMARDs), any bDMARD or JAK inhibitor should be added to the csDMARD. If this fails, any other bDMARD (from another or the same class) or tsDMARD is recommended. On sustained remission, DMARDs may be tapered, but not be stopped. Levels of evidence and levels of agreement were mostly high.

CONCLUSIONS

These updated EULAR recommendations provide consensus on the management of RA with respect to benefit, safety, preferences and cost.

Assessments of the unmet need in the management of patients with rheumatoid arthritis: analyses from the NOR-DMARD registry

Objective

To describe the outcomes of MTX and biologic DMARD (bDMARD) treatment in patients with RA and assess unmet needs in patients who fail treatment, using real-world data from the Norwegian DMARD (NOR-DMARD) registry.

Methods

Data included RA treatment courses from January 2007 until July 2016. Patients received MTX monotherapy (in MTX-naïve patients), bDMARD monotherapy, bDMARDs + MTX, or bDMARDs + other conventional synthetic DMARDs (csDMARDs). DAS28-4(ESR) was used to measure remission (<2.6) and inadequate response (>3.2) across all groups at Months 6 and 12. Estimated ACR20/50/70 and EULAR good and good/moderate response rates (based on DAS28-4[ESR] score) for bDMARDs were modelled at Months 6 and 12 using logistic mixed regression. DAS28-4(ESR) scores and changes from baseline, and rates and reasons for discontinuation, were evaluated for all groups over 24 months.

Results

The 2778 treatment courses in this analysis included 714 MTX monotherapy, 396 bDMARD monotherapy, 1460 bDMARDs + MTX and 208 bDMARDs + other csDMARDs. Of patients with DAS28-4(ESR) data at Months 6 and 12 (25.0–34.1%), 33.9–47.2% did not switch treatment and were inadequate-responders at Month 12. There were no significant differences in efficacy between bDMARD groups (bDMARD monotherapy, or bDMARDs + MTX or other csDMARDs). Lack of efficacy was the most common reason for stopping treatment across all groups (13.7–22.1% over 24 months).

Conclusion

An unmet treatment need exists for patients still experiencing inadequate response to MTX monotherapy and bDMARDs as monotherapy or in combination with MTX/other csDMARDs after 12 months.

Trial registration

ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT01581294.

Drug survival and the associated predictors in South Korean patients with rheumatoid arthritis receiving tacrolimus

BACKGROUND/AIMS

To investigate the drug survival rate of tacrolimus (TAC) and analyze the potential predictors of this rate in patients with rheumatoid arthritis (RA) in routine care.

METHODS2018-01-16

In this retrospective longitudinal study, we enrolled 102 RA patients treated with TAC from April 2009 to January 2014 at a tertiary center in South Korea. The causes of TAC discontinuation were classified as lack of efficacy (LOE), adverse events (AEs), and others. The drug survival rate was estimated using the Kaplan-Meier method and the predictors of this rate were identified by Cox-regression analyses.

RESULTS

TAC was discontinued in 27 of 102 RA patients (26.5%). The overall 1-, 2-, 3-, and 4-year TAC continuation rates were 81.8%, 78.4%, 74.2%, and 69.1%, respectively and the median follow-up period from the start of TAC was 32.5 months. The number of TAC discontinuations due to LOE, AEs, and others were 15 (55.6%), 11 (40.7 %), and 1 (3.7%), respectively. The baseline high disease activity was a significant risk factor for TAC discontinuation after adjusting for confounding factors (hazard ratio [HR], 2.49; 95% confidence interval [CI], 1.16 to 5.35; p = 0.019). In addition, underlying interstitial lung disease was significantly associated with TAC withdrawal due to AEs (HR, 3.49; 95% CI, 1.06 to 11.46; p = 0.039).

CONCLUSIONS

In our study, TAC showed a good overall survival rate in patients with RA in real clinical practice. This suggests that the long-term TAC therapy has a favorable efficacy and safety profile for treating RA.

Putting recommendations into practice: Australian rheumatologists' opinions on leflunomide use in rheumatoid arthritis

Leflunomide is the most recently introduced conventional disease-modifying anti-rheumatic drugs in Australia. It has several unique methods for initiation, unique monitoring recommendations and a distinctive cessation protocol in the event of serious toxicity. The aim of this study was to evaluate initiation and monitoring practices of Australian rheumatologists using leflunomide. A survey was emailed twice, approximately 3 months apart to 332 rheumatologist members of the Australian Rheumatology Association. Wave analysis was used to assess evidence of non-response bias. The response rate to the survey was 20% and there was no difference between the responses of waves 1 and 2. Fifty percent of the respondents indicated that 20 mg once daily was the initial dose of leflunomide that they most commonly prescribed, 45% indicated 10 mg once daily, whilst only 3% preferred to initiate leflunomide at 100 mg daily for 2-3 days followed by 10 mg once a day as recommended when first marketed. Of the responders, 12% had used doses above 20 mg daily and 70% had used alternate daily dosing with leflunomide. In a patient taking leflunomide with an ALT or AST >3 times the ULN on two or more blood tests, 75% of responders indicated they would stop leflunomide immediately and 20% would follow cessation by administering a cholestyramine washout. The choice of initial leflunomide dose among responding Australian rheumatologists varied considerably, although most preferred not to use the loading dose. Despite the recommendation of clinical guidelines, the use of a cholestyramine washout procedure for hepatic toxicity is not universal.

Intracellular CD3+ T Lymphocyte Teriflunomide Concentration Is Poorly Correlated with and Has Greater Variability Than Unbound Plasma Teriflunomide Concentration

Leflunomide's active metabolite teriflunomide inhibits dihydro-oroate dehydrogenase, an enzyme essential to proliferation of T lymphocytes. As teriflunomide must reach the target site to have this effect, this study assessed the distribution of teriflunomide into T lymphocytes, as intracellular concentrations may be a superior response biomarker to plasma concentrations. CD3 MicroBeads (Miltenyi Biotec, Bergisch Gladbach, Germany) were used to extract CD3⁺ T cells from the peripheral blood of patients with rheumatoid arthritis who were taking a stable dose of leflunomide. Unbound plasma and intra-CD3⁺ T cell teriflunomide concentrations were quantified using liquid chromatography-mass spectrometry. Concentration (log transformed) and partition differences were assessed through paired Student t tests. Sixteen patients provided plasma steady-state teriflunomide samples, and eight provided a sample 6-12 weeks later. At time-point one, the geometric mean teriflunomide concentration (range) in CD3⁺ T cells was 18.12 μg/L (6.15-42.26 μg/L) compared with 69.75 μg/L (32.89-263.1 μg/L) unbound in plasma (P < 0.001). The mean partition coefficient (range) for unbound plasma teriflunomide into CD3⁺ T cells was 0.295 (0.092-0.632), which was significantly different from unity (P < 0.001). The median (range) change in teriflunomide concentration between the two time points was 14% (-10% to 40%) in unbound plasma and -29% (-69 to 138%) for CD3⁺ T cells. Because teriflunomide concentrations in CD3⁺ T cells were lower and displayed a higher intraindividual variability than the unbound plasma concentrations, its applicability as a therapeutic drug-monitoring marker may be limited.

Combination leflunomide and methotrexate in refractory rheumatoid arthritis: a biologic sparing approach

BACKGROUND

In resource-constrained settings where biologic agents are not widely available, there are limited therapeutic options for patients with rheumatoid arthritis (RA) refractory to other synthetic disease modifying antirheumatic (DMARD) therapies. The aim of this study is to evaluate the effectiveness and safety of leflunomide (LEF) with methotrexate (MTX) in refractory RA.

METHODS

A retrospective record review of adult RA patients treated with LEF/MTX. Demographic details, adverse reactions, and the 3-variable 28 joint disease activity score (DAS28-3) were recorded at initiation of LEF/MTX therapy, and after 4 and 12 months of treatment.

RESULTS

Of 194 patients, most were middle-aged seropositive Black African females, with established disease [mean (standard deviation, SD) disease duration 9.4 (8.2) years] and time on previous DMARDs of 7.0 (5.5) years. Before adding LEF, the mean (SD) dose of MTX was 21.7 (3.5) mg/week, and 87.6% of patients used low dose oral corticosteroids. A good or moderate EULAR response was achieved by 44% and 42% of patients, and the retention rate was 71%. Major infections were seen in 6 patients: comprising 2 deaths, 3 cases of leucopaenia and septicaemia and 1 case of tuberculosis. Hepatotoxicity (n = 3), intolerable gastrointestinal symptoms (n = 3), and hypertension (n = 17) were the most common problems. Predictors of remission or low disease activity at 12 months was a baseline DAS28-3 ⩽ 5.5 [odds ratio (OR) = 2.7; 95% confidence interval (CI) 1.1-5.6; p = 0.01].

CONCLUSIONS

LEF/MTX was effective in the majority of patients in this cohort of mainly Black African women who failed other combination synthetic DMARDs, particularly in those with moderate disease activity at the time of addition of LEF. Infections and hypertension were important complications. In a setting where biologic DMARDs are not readily accessible, the combination of LEF/MTX is a cost-effective approach.

Genetic polymorphism of CYP1A2 but not total or free teriflunomide concentrations is associated with leflunomide cessation in rheumatoid arthritis

AIM

Leflunomide, via its active metabolite teriflunomide, is used in rheumatoid arthritis (RA) treatment, yet approximately 20 to 40% of patients cease due to toxicity. The aim was to develop a time-to-event model describing leflunomide cessation due to toxicity within a clinical cohort and to investigate potential predictors of cessation such as total and free teriflunomide exposure and pharmacogenetic influences.

METHODS

This study included individuals enrolled in the Early Arthritis inception cohort at the Royal Adelaide Hospital between 2000 and 2013 who received leflunomide. A time-to-event model in nonmem was used to describe the time until leflunomide cessation and the influence of teriflunomide exposure and pharmacogenetic variants. Random censoring of individuals was simultaneously described. The clinical relevance of significant covariates was visualized via simulation.

RESULTS

Data from 105 patients were analyzed, with 34 ceasing due to toxicity. The baseline dropout hazard and baseline random censoring hazard were best described by step functions changing over discrete time intervals. No statistically significant associations with teriflunomide exposure metrics were identified. Of the screened covariates, carriers of the C allele of CYP1A2 rs762551 had a 2.29 fold increase in cessation hazard compared with non-carriers (95% CI 2.24, 2.34, P = 0.016).

CONCLUSIONS

A time-to-event model described the time between leflunomide initiation and cessation due to side effects. The C allele of CYP1A2 rs762551 was linked to increased leflunomide toxicity, while no association with teriflunomide exposure was identified. Future research should continue to investigate exposure-toxicity relationships, as well as potentially toxic metabolites.

Biologic and oral disease-modifying antirheumatic drug monotherapy in rheumatoid arthritis

Clinical evidence demonstrates coadministration of tumour necrosis factor inhibitor (TNFi) agents and methotrexate (MTX) is more efficacious than administration of TNFi agents alone in patients with rheumatoid arthritis, leading to the perception that coadministration of MTX with all biologic agents or oral disease-modifying antirheumatic drugs is necessary for maximum efficacy. Real-life registry data reveal approximately one-third of patients taking biologic agents use them as monotherapy. Additionally, an analysis of healthcare claims data showed that when MTX was prescribed in conjunction with a biologic agent, as many as 58% of patients did not collect the MTX prescription. Given this discrepancy between perception and real life, we conducted a review of the peer-reviewed literature and rheumatology medical congress abstracts to determine whether data support biologic monotherapy as a treatment option for patients with rheumatoid arthritis. Our analysis suggests only for tocilizumab is there evidence that the efficacy of biologic monotherapy is comparable with combination therapy with MTX.

Adding tocilizumab or switching to tocilizumab monotherapy in methotrexate inadequate responders: 24-week symptomatic and structural results of a 2-year randomised controlled strategy trial in rheumatoid arthritis (ACT-RAY)

Objective

In patients with active rheumatoid arthritis (RA) despite methotrexate, to compare the efficacy of adding tocilizumab to that of switching to tocilizumab monotherapy.

Methods

Double-blind, 2-year study in which adults with active RA (DAS28 >4.4) despite methotrexate were randomly assigned either to continue methotrexate with the addition of tocilizumab (MTX+TCZ) 8 mg/kg every 4 weeks or switch to tocilizumab and placebo (TCZ+PBO). The primary endpoint was the DAS28–erythrocyte sedimentation rate (ESR) remission rate at week 24. Secondary objectives included other symptomatic outcomes, quality of life and progression of structural damage.

Results

Of 556 randomly assigned patients, 512 (92%) completed 24 weeks. DAS28–ESR remission rates were 40.4% for TCZ+MTX and 34.8% for TCZ+PBO (p=0.19); American College of Rheumatology 20/50/70/90 rates were 71.5%/45.5%/24.5%/5.8% (TCZ+MTX) and 70.3%/40.2%/25.4%/5.1% (TCZ+PBO; differences not significant). A significant difference between groups was seen for low DAS28 (61.7% vs 51.4%). Radiographic progression was small and not different between groups (Genant–Sharp score progression ≤ smallest detectable change in 91% (TCZ+MTX) and 87% (TCZ+PBO)). Rates per 100 patient-years of serious adverse events and serious infections were 21 and six, respectively, for TCZ+MTX and 18 and six, respectively, for TCZ+PBO. Alanine aminotransferase elevations greater than threefold the upper limit of normal occurred in 7.8% and 1.2% of TCZ+MTX and TCZ+PBO patients, respectively.

Conclusion

No clinically relevant superiority of the TCZ+MTX add-on strategy over the switch to tocilizumab monotherapy strategy was observed. The combination was more commonly associated with transaminase increases. Meaningful clinical and radiographic responses were achieved with both strategies, suggesting that tocilizumab monotherapy might be a valuable treatment strategy in suitable RA patients.

Interleukin-6 regulates anti-arthritic effect of methotrexate via reduction of SLC19A1 expression in a mouse arthritis model

Introduction

Methotrexate (MTX) enters cells via the reduced folate carrier SLC19A1, suggesting that SLC19A1 is associated with the efficacy of MTX. We here examined the relationship between the efficacy of MTX and the expression of SLC19A1 in glucose 6-phosphate isomerase (GPI)-induced arthritis. We found that interleukin-6 (IL-6) regulated the expression of SLC19A1, so we studied the effect of a combination of MTX and anti-mouse IL-6 receptor antibody (MR16-1).

Methods

GPI-induced arthritis was induced by intradermal immunization with recombinant GPI. MTX was given from the first day of immunization. Mice were injected once with MR16-1 10 days after immunization. The levels of SLC19A1 mRNA in whole hind limbs and immune cells were measured. Synovial cells from arthritic mice were cultured with cytokines, and cell proliferation and gene expressions were measured.

Results

MTX inhibited the development of GPI-induced arthritis; however, the efficacy of MTX gradually diminished. SLC19A1 expression in immunized mice with arthritis was lower than in intact mice; moreover, SLC19A1 expression in arthritic mice was further decreased when they were treated with MTX. IL-6 was highly expressed in whole hind limbs of arthritic mice. In an in vitro study using synovial cells from arthritic mice, IL-6 + soluble IL-6 receptor (sIL-6R) weakened the anti-proliferative effect of MTX and reduced SLC19A1 expression. Finally, although MR16-1 did not improve arthritis at all when administered on day 10, MTX in combination with MR16-1 more potently reduced the development of arthritis than did MTX alone. When used in combination with MTX, MR16-1 apparently reversed the decrease in SLC19A1 induced by MTX alone.

Conclusions

In the present study, we demonstrated for the first time that IL-6 reduced the efficacy of MTX by decreasing the expression of SLC19A1, which is important for MTX uptake into cells.

Effectiveness of sulfasalazine and methotrexate in 1102 DMARD-naive patients with early RA

OBJECTIVE

To compare baseline characteristics, responses and drug survival in patients with early RA starting SSZ or MTX in a real-life setting.

METHODS

The analyses included DMARD-naïve patients with RA (disease duration ≤ 1 year) starting SSZ or MTX. Three- and 6-month effectiveness was compared by unadjusted analysis and with adjustment for propensity score quintile. In addition, effectiveness in SSZ- and MTX-treated patients matched for RF status and baseline DAS-28 was compared.

RESULTS

SSZ-treated patients (n = 175) had lower baseline disease activity than patients treated with MTX (n = 927) [mean 28-joint DAS (DAS-28) 4.4 vs 5.0, P < 0.001], and were less often RF positive (50 vs 61%, P = 0.006). Six-month mean ΔDAS-28 was smaller with SSZ than MTX (-1.0 vs -1.5, P = 0.003); the difference was not significant after adjustment for propensity score quintile (P = 0.36). For SSZ/MTX, 3-month ACR50 and European League Against Rheumatism (EULAR) good responses were 9/23% (P < 0.001) and 24/31% (P = 0.14), respectively. Three-year drug survival was superior for MTX (P < 0.001) and estimated 1-year survival rates were 42/75% for SSZ/MTX. In patients matched for baseline DAS-28 and RF, mean ΔDAS-28 (MTX -1.2, P = 0.55 vs SSZ) and EULAR good responses (39 vs 37%, P = 0.74) were similar at 6 months; drug survival was superior for MTX (P < 0.001).

CONCLUSION

Patients treated with SSZ as first DMARD were more often RF negative and had lower baseline disease activity. Drug survival was superior for MTX, and effectiveness was greater with MTX than with SSZ although the difference was reduced when adjusting for differences in baseline characteristics.

Leflunomide in clinical practice. A retrospective observational study on use of leflunomide in New Zealand

AIM

The aim was to study the side-effect profile and the survival characteristics of leflunomide used in a regional patient population in New Zealand (NZ).

METHOD

  Patients were identified using special authority forms (SAFs) that had been prospectively filed from January 2001 to June 2007. Statistical analysis of survival data was done using the Kaplan-Meier (KM) method.

RESULTS

Of 110 patients identified on SAFs, only 90 were suitable for analysis. The percentage of women and men were 74% and 26%, respectively. Their mean age was 55.58 years ± 13.44. Their diagnoses were rheumatoid arthritis 75%, psoriatic arthritis 15%, others 10%. Their mean disease duration was 11.31 years ± 8.93. The mean number of concomitant disease-modifying antirheumatic drugs used was 1.95. These were methotrexate (MTX) in 48, hydroxychloroquine in 29, prednisone in 30 and sulfasalazine in 27. Thirty-two of 90 (35.5%) discontinued treatment, 12 (13.3%) of these were in the first 6 months. The mean time to discontinuation was 14.2 months. Twenty-three of 32 discontinuations were for side-effects. The incidence of side-effects were similar to those of an earlier 2-year NZ study, and better than other earlier studies. Leflunomide survival using the KM method at 5 years was 57%, higher than suggested by previous leflunomide studies and this compares well with MTX studies.

CONCLUSIONS

Our study suggests a better side-effect profile and a better drug survival for leflunomide than suggested by previous studies with survival comparable to that of MTX.

Influence of long-term leflunomide treatment on serum amyloid concentration in rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a chronic, inflammatory disease that requires intervention with disease-modifying antirheumatic drugs (DMARDs) to stop disease progression. Leflunomide (LEF) is a DMARD with anti-inflammatory and immunomodulatory properties. As its primary mode of action, LEF reversibly inhibits dihydroorotate dehydrogenase, a key enzyme in de novo biosynthesis of pyrimidine in cells. Serum amyloid A protein (SAA) is elevated in inflammatory states and high SAA levels indicate a risk of developing secondary amyloidosis. The aim of this study was to investigate the effects of long-term LEF treatment on SAA levels and disease activity in a group of RA patients. The study group consisted of 50 consecutive RA patients (43 F, 7 M) treated with leflunomide. All patients had a clinical evaluation and SAA measurements taken at two consecutive visits during months 0, 1, 3, 6 and 12. Mean SAA concentrations decreased significantly in the first months of LEF therapy (up to the 6th month) with a more pronounced effect in patients with higher SAA levels. However, by the 12(th) month of treatment, the mean SAA level did not differ significantly from the SAA level at the start of treatment. At the same time though, other clinical and laboratory parameters of RA activity indicated that the disease activity decreased. Results demonstrated that in patients with active RA LEF therapy provided a significant, long-term reduction of inflammatory activity, as measured by the classic parameters of disease activity. During the treatment, SAA concentrations decreased significantly, followed by a slight increase, in spite of a reduction in other classical indicators of inflammatory response.

Reappraisal of the clinical use of leflunomide in rheumatoid arthritis and psoriatic arthritis

Leflunomide is a disease-modifying antirheumatic drug (DMARD) that has been in routine clinical use for the treatment of rheumatoid arthritis (RA) and psoriatic arthritis for a decade. In RA, clinical trials of up to two years' duration showed that leflunomide monotherapy was equivalent to methotrexate in clinical and radiographic disease outcomes (tender and swollen joint counts, physician and patient global assessments, American College of Rheumatology and Disease Activity Score responses, slowing or halting of radiographic progression). In a number of studies, quality of life measurements indicated that leflunomide is superior to methotrexate. Leflunomide has been studied in combination with methotrexate and shows efficacy in patients only partly responsive to this agent. Recent trials have shown that leflunomide can be used safely with biologic DMARDs, including antitumor necrosis factor agents and rituximab as part of the treatment algorithm in place of methotrexate as a cotherapy. Leflunomide has demonstrated efficacy as a monotherapy in psoriatic arthritis, and it also has a beneficial effect in psoriasis. Postmarketing studies have shown that retention on treatment with leflunomide is equal to methotrexate and superior to other DMARDs. In general, its side effect profile is acceptable compared with other DMARDS, with nausea, diarrhea, and hair fall occurring commonly, but only rarely leading to discontinuation. Liver toxicity is the most significant problem in clinical use although it is uncommon. Peripheral neuropathy, hypertension, pneumonitis, and cytopenia occur more rarely. Leflunomide is contraindicated in pregnancy and should be used with caution in women during child-bearing years. In this review, the place of leflunomide in therapy is discussed and practical advice informed by evidence is given regarding dosing regimens, safety monitoring, and managing side effects. Leflunomide remains one of the most useful of the nonbiologic DMARDs.

Leflunomide in the treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic and highly morbid disease affecting approximately 1% of the world's population. With the advent of disease-modifying antirheumatic drugs, patients are increasingly able to maintain control of their arthritis and prevent joint destruction. However, not all patients respond adequately to any single disease-modifying antirheumatic drug, and many newer parenteral therapies are cost prohibitive. Leflunomide, an inhibitor of pyrimidine biosynthesis, is the first oral disease-modifying antirheumatic drug to have been approved for rheumatoid arthritis in the USA in the last 15 years, and is now widely used in over 70 countries around the world. Leflunomide is efficacious when used as monotherapy or in combination with methotrexate to treat patients with rheumatoid arthritis, and is generally well tolerated. As clinical use increases, new ways to use leflunomide in order to minimize toxicity and maximize efficacy are being explored.

Seven-year follow-up of infliximab therapy in rheumatoid arthritis patients with severe long-standing refractory disease: attrition rate and evolution of disease activity

Introduction

This study is based on the results from a Belgian expanded access program in which patients with active refractory and erosive rheumatoid arthritis (RA) were treated with intravenous infusions of infliximab in combination with methotrexate. The objectives of this study were to evaluate the continuation rate of infliximab and its clinical effect over a 7-year period and to document the reasons for discontinuation.

Methods

Between 2000 and 2001, 511 patients with severe and refractory RA were enrolled and treated with infliximab. After 7 years, apart from routine clinical follow-up, treating rheumatologists were asked to complete a questionnaire designed specifically for the present study to evaluate the current therapy with infliximab, the level of disease activity (Disease Activity Score in 28 joints [DAS28]) and the reasons for infliximab discontinuation.

Results

After 7 years, 160 of 511 patients (31%) were still on infliximab treatment. The major reasons for infliximab discontinuation included lack of efficacy (104 patients), adverse events (107 patients) and elective change of therapy (70 patients). The majority of cases of treatment discontinuation for safety reasons occurred during the first 2 years. In contrast, discontinuation due to ineffectiveness showed a more constant rate over the 7-year period. Mean DAS for patients still on treatment with infliximab decreased from 5.7 (standard error [SE] 0.1) at baseline to 3.0 (SE 0.1) at year 4 and remained that low until year 7 (3.0 [SE 0.1]). Low disease activity (defined as DAS28 <3.2) was present in 60.9% of patients, and 45.5% achieved remission (DAS28 <2.6). DAS28 at the time of treatment discontinuation due to ineffectiveness decreased over the 7-year period from 5.6 (SE 0.3) in 2001 to 4.8 (SE 0.3) in 2008.

Conclusions

This observational study revealed that patients who continue to receive infliximab experience sustained clinical benefit. The majority of safety issues occurred during the first 2 years of infliximab therapy. We observed that the DAS at the time of therapy discontinuation showed a trend to decrease over time.

Leflunomide use in New Zealand. A national prospective post-marketing study

BACKGROUND

This post-marketing study aimed to record rates of retention, adverse effects and efficacy of leflunomide in the treatment of rheumatoid arthritis (RA). The secondary objectives were to make a semi-quantitative assessment of response to treatment and to examine the effect of a loading dose on adverse events and treatment duration.

METHODS

Rheumatologists in New Zealand contributed to a prospective leflunomide treatment registry. Baseline data were collected on leflunomide initiation and information about treatment experience was sought every 6 months. Each patient was followed for 2 years. Kaplan-Meier analysis was used to evaluate differences in stopping rates between lack of efficacy and adverse effects. Hazard analysis was used to evaluate the effect of using a loading dose on retention rate.

RESULTS

Three hundred and eight patients were enrolled in the study; complete follow-up data were available for 244 patients. Retention of patients on leflunomide was 64% at 12 months and 49.4% at 2 years. Reasons for stopping were adverse events (54 patients), loss of effect (25 patients) and miscellaneous reasons (14 patients). Use of a loading dose had no effect on retention; there was no difference in treatment duration between those who stopped from adverse effects or loss of efficacy.

CONCLUSION

Leflunomide was effective in treating RA in a group that had longer duration of disease and greater prior use of disease-modifying agents than the groups studied in clinical trials. Rates of withdrawal were lower than those reported in other post-marketing studies, but were higher than those from phase III clinical trials.

Genetic polymorphism of CYP1A2 and the toxicity of leflunomide treatment in rheumatoid arthritis patients

OBJECTIVE

Leflunomide is a disease-modifying antirheumatic drug used for treating rheumatoid arthritis (RA). In vitro studies demonstrated that cytochromes P450 (CYPs), mainly CYP1A2 and CYP2C19, might be involved in leflunomide activation. The aim of our study was to investigate whether genetic polymorphisms of CYP1A2, CYP2C19, and CYP2C9 influence leflunomide toxicity.

METHODS

A genotyping approach was used to determine CYP1A2*1F, CYP2C19*2, CYP2C19*17, CYP2C9*2, and CYP2C9*3 alleles in 105 RA patients.

RESULTS

Leflunomide treatment was well tolerated by 62 patients, whereas 43 patients discontinued the treatment within the first year due to toxicity. Patients with CYP1A2*1F CC genotype had a 9.7-fold higher risk for overall leflunomide-induced toxicity than did the carriers of CYP1A2*1F A allele [P = 0.002, odds ratio = 9.708, 95% confidence interval = 2.276-41.403]. No significant association between the CYP2C19 and CYP2C9 genotypes and the leflunomide toxicity was observed.

CONCLUSION

Our results suggest that the CYP1A2*1F allele may be associated with leflunomide toxicity in RA patients.

Assessment of Adherence to and Persistence on Disease-Modifying Antirheumatic Drugs (DMARDs) in Patients With Rheumatoid Arthritis

OBJECTIVE

Biologic disease-modifying antirheumatic drugs (DMARDs) are efficacious for treating rheumatoid arthritis (RA). However, measurements of relative effectiveness, including treatment adherence and persistence, are lacking. We evaluated adherence and persistence during new episodes of use of traditional and biologic DMARDs.

METHODS

Using Tennessee Medicaid databases (1995-2004), we assembled a retrospective cohort of patients diagnosed with RA, and identified new episodes of use for 12 DMARD regimens. We evaluated persistence through survival analyses, and adherence within episodes through the medication possession ratio. A risk score was included in the analyses to account for measured confounders.

RESULTS

We identified 14,932 patients with RA; 6018 patients had 10,547 episodes of new use of DMARDs. Considering methotrexate as the reference and after adjustment for measured confounders, episodes of new use of sulfasalazine [adjusted hazard ratio (aHR) = 1.59; 95% confidence interval (CI) = 1.47-1.72] and infliximab alone (aHR = 1.37, 95% CI = 1.09-1.73) were more likely to be discontinued; and new episodes of etanercept (aHR = 0.82, 95% CI = 0.73-0.92) and methotrexate + adalimumab (aHR = 0.63, 95% CI = 0.48-0.84) were less likely to be discontinued. Compared with methotrexate, adherence was higher for leflunomide, infliximab, etanercept, and adalimumab and lower for sulfasalazine and all combined therapies.

CONCLUSIONS

We developed an approach to assess persistence on and adherence to the most common DMARD therapies. In this large cohort, persistence and adherence to leflunomide and most biologic DMARD therapies were at least comparable to methotrexate. Adherence was lower for sulfasalazine and all combined therapies.

T cell costimulation: a rational target in the therapeutic armamentarium for autoimmune diseases and transplantation

T cells are central mediators of adaptive immunity. As such, they are involved in both normal immune responses (e.g., rejection of a transplanted organ) and abnormal ones (e.g., rheumatoid arthritis). T cells require both antigen-specific and costimulatory signals for their full activation. Advances in protein engineering and an increased understanding of the immune response have culminated in the evolution and creation of protein therapeutics that target specific costimulatory molecules. The selective costimulation modulator abatacept (CTLA-4Ig) binds to CD80 and CD86, blocking interaction with CD28, and is approved for the treatment of moderate to severe rheumatoid arthritis. Belatacept, currently enrolling phase III trials in renal transplantation, was rationally designed from abatacept to bind with more avidity to CD86, providing the more potent immunosuppressive properties required for immunosuppression in transplantation. This review describes the relevant immunology and summarizes recent clinical findings on these two molecules. Although both inhibit the CD28 costimulatory pathway, they are tailored for specific disease states--abatacept for autoimmune diseases and belatacept for transplantation.

Step-up combination versus switching of non-biological disease-modifying antirheumatic drugs in rheumatoid arthritis: results from a retrospective observational study

BACKGROUND

In rheumatoid arthritis (RA), treatment with disease-modifying antirheumatic drugs (DMARDs) frequently needs to be changed because of insufficient effectiveness.

AIM

To compare the clinical outcomes of two potential strategies for patients experiencing DMARD discontinuations related to ineffectiveness: switching to another DMARD or step-up combination therapy of the present DMARD with a new one.

METHODS

In a large observational database of 4585 DMARD courses in 1214 patients with RA, all patients who had experienced a change in treatment regimen were identified, and retention, effectiveness and safety of these subsequent treatment courses between the two strategies (switching vs step-up combination). All analyses were stratified according to the type of the new DMARD into methotrexate (MTX), sulphasalazine (SSZ) or leflunomide (LEF); all other DMARDs were excluded.

RESULTS

Kaplan-Meier analysis for MTX courses showed no significant difference in overall retention rates between the strategies of adding MTX and switching to MTX (p = 0.49 by log rank test). Likewise, switching or adding did not result in significantly different retention rates for SSZ and LEF (p = 0.61 and 0.74, respectively). This similarity between strategies remained after adjusting for several confounding variables. The frequencies of treatment terminations related to ineffectiveness or toxicity were likewise similar between the two strategies for the MTX, SSZ and LEF groups. This was also confirmed by the similarity of erythrocyte sedimentation rates that were reached at the end of the two therapeutic strategies for all three drugs, in adjusted analysis.

CONCLUSION

Given all limitations of observational studies, the present data indicate that in situations of ineffective DMARD treatments, step-up combination therapy using traditional DMARDs, such as MTX, SSZ or LEF, bears no clear clinical advantage over switching to the new DMARD. Our results do not implicate any predication about step-up design including biologicals, where the benefit of combination therapy has been suggested convincingly.

Sulphasalazine inhibits human antigen-specific immune responses in vivo

OBJECTIVE

To study the effects of the antirheumatic drug sulphasalazine (SASP) on the immune system by analysing systemic and gut-associated immune responses.

METHODS

A total of 23 healthy volunteers were treated with either SASP or placebo for 5 weeks in a double-blind fashion and immunised 2 weeks after the initiation of treatment. Specific immune responses were triggered by subcutaneous immunisation with tetanus toxoid and by peroral immunisation with inactivated influenza vaccine. The effects of treatment on specific immunity to tetanus and influenza were evaluated by enzyme-linked immunospot assay quantifying the number of circulating specific and total antibody-producing cells (spot-forming cells (SFC)) at 6, 8 and 10 days after immunisation.

RESULTS

An immunosuppressive effect of SASP on systemic immune response was observed with a decrease in the total number of IgG-SFC, IgG anti-tetanus SFC and IgG anti-tetanus antibody levels in serum. SASP also exerted an immunosuppressive effect on the mucosa-associated immune system as seen from its down-regulating effect on the total number of circulating IgA SFC.

CONCLUSIONS

These data show firstly that SASP exerts an immunosuppressive effect on defined immune responses to immunisation in vivo, and secondly that both mucosa-associated and systemic immunity are affected by SASP treatment.

Estimating the cost and health status consequences of treatment with TNF antagonists in patients with psoriatic arthritis

OBJECTIVES

Tumour necrosis factor (TNF) has been shown to improve the outcomes in patients with psoriatic arthritis (PsA). We estimate the long-term impact on health status of prescribing the TNF antagonist etanercept, and evaluate the cost-effectiveness in a health economic model.

METHODS

The relationship between disability (Health Assessment Questionnaire) and health state utility was explored to estimate the quality-adjusted life years (QALYs) gained from the TNF antagonist etanercept. A model was then used to compare sequences of treatments for PsA after failure of two conventional disease modifying anti-rheumatic drugs (DMARDs). One arm commences on etanercept therapy and this is compared with a strategy commencing with combination therapy of methotrexate and ciclosporin and another commencing with leflunomide. Individual patient data from Phase III etanercept trials is used to populate the model supported by published evidence from extensive literature searches. By incorporating a life table specific for a PsA population, and using a number of evidence- and expert opinion-based assumptions for disease progression, the model was extended beyond the trial duration to a 10-yr time horizon. Cost offsets were produced by avoiding surgery through delayed progression; drug and monitoring costs were also modelled.

RESULTS

Over the 10 yrs, modelled etanercept treatment gave 0.82 more QALYs when compared with combination therapy with methotrexate and ciclosporin, and 0.65 more QALYs in comparison with leflunomide. This equates to a central estimate for the cost per QALY of pound28 189 and pound28 189 for ciclosporin and leflunomide, respectively. Sensitivity analyses demonstrated this could vary by as much as +/-28%.

CONCLUSIONS

With limited data currently available, the potential cost-effectiveness of etanercept in DMARD failures for adults with PsA appears encouraging. The result for other TNF antagonists will depend on how their relative efficacy and drug price compares with etanercept. A number of limitations are described and priorities for further research suggested.

The Effectiveness of Methotrexate for the Escape by Salazosulfapyridine

Although disease modifying anti-rheumatic drugs (DMARDs) are used in the treatment of rheumatoid arthritis (RA), the selection of agents in the case of relapse (escape phenomenon) lacks clear-cut standards. We compared the effectiveness in a salazosulfapyridine and then methotrexate (SASP-->MTX) group with that in the mothotrexate (SASP+MTX) group after escape phenomenon expression in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) data. Outpatients of the Matsubara Mayflower Hospital with a history of DMARD administration during the 4 years prior to May 2003 were studied. The CRP level in the SASP-->MTX group (n=8) after the escape phenomenon expression showed a decline after 3 months, but no decline was seen even after 3 months the two in the CRP level in the SASP+MTX group (n=10). However, the difference between groups was not significant. The fluctuation in ESR was similar to that in CRP. However, ESR was significantly lower in the SASP-->MTX group 20 weeks after escape phenomenon expression. In evaluating treatment effectiveness after escape phenomenon expression in each group, SASP-->MTX was effective in 10 and SASP+MTX in 7 patients. Side effects necessitated cessation of treatment in 1 patient in the SASP-->MTX group. Treatment continued in 4 patients in the SASP-->MTX group and 2 in the SASP+MTX group, even though side effects occurred. It should be borne in mind that combination therapy often has greater clinical benefit than single agent therapy but not always.

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.

Survival of surgical endodontic treatment performed in a dental teaching hospital: a cohort study

AIM

To assess the survival function of surgical endodontic treatment performed at least 1 year before in a dental teaching hospital.

METHODOLOGY

A total of 194 teeth surgically treated between 1991 and 2001 were recalled and examined clinically and radiographically using a set of strict criteria. The Kaplan-Meier method and log rank test were used to evaluate the survival time. Confounding factors were examined by Cox regression analysis.

RESULTS

The median survival time of the 154 first-time surgically treated teeth was 92.1 months (95% CI: 40.9-143.4) and that of the 40 resurgery cases was 39.1 months (95% CI: 6.1-72.1) up to the date of recall. There was a significant difference in the length of survival between the two groups. For those first-time surgery cases, the preoperative marginal bone loss and the operator had a significant influence on the survival time (P < 0.05).

CONCLUSIONS

The survival of surgical endodontic treatment declined nonlinearly with time. The preoperative marginal bone loss, operator and resurgery were important factors affecting the survival of this treatment modality.

Therapeutic drug monitoring of A77 1726, the active metabolite of leflunomide: serum concentrations predict response to treatment in patients with rheumatoid arthritis

BACKGROUND

Leflunomide is the prodrug of the disease modifying antirheumatic metabolite A77 1726. More than 50% of patients withdraw from leflunomide treatment within one year, mainly because of adverse drug reactions. Therapeutic drug monitoring of A77 1726 may be useful in predicting the efficacy of leflunomide treatment.

OBJECTIVE

To study the relation between A77 1726 steady state serum concentrations and disease activity using the 28 joint (DAS28) response.

METHODS

Outpatients with rheumatoid arthritis on a stable leflunomide dose for >4 months were included. DAS28 score and adverse drug reactions were recorded. Blood samples were taken for determination of A77 1726 concentrations. The primary end point was the relation of serum A77 1726 concentrations with DAS28 response category.

RESULTS

Serum A77 1726 concentrations were determined in 52 patients. A receiver operating characteristic (ROC) curve showed an area under the curve (AUC) of 0.73 (95% confidence interval, 0.54 to 0.93) (p<0.05). The sensitivity exceeded 99% at concentrations below 16 mg/l. DAS28 values at the point of sampling showed no relation with A77 1726 concentrations (AUC of the ROC curve = 0.50 (0.33 to 0.67) (NS)).

CONCLUSIONS

A77 1726 steady state serum concentrations show a relation with DAS28 response. Determination of serum A77 1726 concentrations in patients with insufficient response to treatment may help when decisions have to be made about continuation of treatment or dose adjustment.

A rapid and simple determination of A77 1726 in human serum by high-performance liquid chromatography and its application for optimization of leflunomide therapy

Leflunomide is a disease-modifying antirheumatic drug, which is bioactivated by formation of A77 1726. In this study a rapid and simple quantitative assay using a reversed phase HPLC-UV method is validated for detection of A77 1726 in human serum. The HPLC-UV method uses a mobile phase consisting of methanol and a KH2PO4-buffer (45 mM, pH = 3) (50:50,v/v), at a flow rate of 1 mL/min. A77 1726 is detected by UV-absorption at 295 nm with a retention time of 8.9 min. Demoxepam is used as internal standard. Validation showed lower and upper limits of quantitation of 0.5 and 100 mg/L, respectively. The assay was linear over the concentration range of 0.5-100 mg/L (r2 > 0.999). Intra- and inter-day precision showed coefficients of variation within 15% over the complete concentration range; accuracy was within 8%. Commonly prescribed drugs to treat rheumatoid arthritis like disease-modifying antirheumatic drugs, analgesics and corticosteroids, and their main metabolites, are separated from A77 1726 with a resolution >2. Serum levels of A77 1726 in 37 patients on leflunomide therapy were determined using this HPLC-UV method. Measured serum A77 1726 serum concentrations in patient samples showed large variability with a range of 3-176 mg/L.