Comparative Effectiveness of Rituximab in Combination with Either Methotrexate or Leflunomide in the Treatment of Rheumatoid Arthritis

Assessment of interactions and dosage recommendations of synthetic DMARDs-Evidence-based and consensus-based recommendations based on a systematic literature search

Conventional synthetic (cs) and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARD) have potential interactions with a multitude of drugs. Furthermore, they sometimes have a lower therapeutic index, particularly in cases of limited organ functions. The aim of this work was to establish evidence-based recommendations on the therapeutic use of DMARDs in the context of drug interactions and dosage recommendations. A systematic literature search was carried out on the issue of drug interactions and dosages in cases of patients with limited kidney function and higher age and suffering from rheumatoid arthritis. A total of 2756 scientific publications were screened and 154 selected of which 68 were scrutinized in detail. Furthermore, the respective product information was also analyzed. A multitude of possible interactions of synthetic DMARDs with different drugs were detected, which were then assessed with respect to the clinical significance and consequences. A consensus process led to making recommendations with which the interactions were classified: A: dangerous combination, B: avoid combination (if possible, pausing DMARD treatment), C: possible combination requiring increased monitoring and potential adjustments in dosage and D: pharmacological interaction without relevance in DMARD standard doses. Apart from that dosage recommendations were established for each csDMARD and tsDMARD depending on kidney function and age. There are 3 primary recommendations and 11 core recommendations on interactions and dosages of csDMARDs and tsDMARDs meant as a practical help for therapeutic decision making and to improve safety in the treatment of rheumatoid arthritis.

[Assessment of interactions and dosage recommendations of synthetic DMARDs-Evidence-based and consensus-based recommendations based on a systematic literature search]

Conventional synthetic (cs) and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARD) have potential interactions with a multitude of drugs. Furthermore, they sometimes have a lower therapeutic index, particularly in cases of limited organ functions. The aim of this work was to establish evidence-based recommendations on the therapeutic use of DMARDs in the context of drug interactions and dosage recommendations. A systematic literature search was carried out on the issue of drug interactions and dosages in cases of patients with limited kidney function and higher age and suffering from rheumatoid arthritis. A total of 2756 scientific publications were screened and 154 selected of which 68 were scrutinized in detail. Furthermore, the respective specialist subject information was also analyzed. A multitude of possible interactions of synthetic DMARDs with different drugs were detected, which were then assessed with respect to the clinical significance and consequences. A consensus process led to making recommendations with which the interactions were classified: A: dangerous combination, B: avoid combination (if possible, pausing DMARD treatment), C: possible combination requiring increased monitoring and potential adjustments in dosage and D: pharmacological interaction without relevance in DMARD standard doses. Apart from that dosage recommendations were established for each csDMARD and tsDMARD depending on kidney function and age. There are 3 primary recommendations and 11 core recommendations on interactions and dosages of csDMARDs and tsDMARDs meant as a practical help for therapeutic decision making and to improve safety in the treatment of rheumatoid arthritis.

Factors Determining Retreatment Time Interval of Rituximab in Korean Patients With Rheumatoid Arthritis

Unlike other biologic agents for rheumatoid arthritis (RA) that are administered at regular intervals even without flare, rituximab can be administered according to the timing of retreatment determined by the physician. Recently, there has been a tendency to prefer on-demand administration for disease flares rather than regular retreatment. We aimed to investigate the retreatment patterns of rituximab in patients with RA and to identify factors associated with extension of the time interval between retreatment courses. This study included RA patients on rituximab treatment who were enrolled in the Korean Rheumatology Biologics registry (KOBIO) or treated at Ajou University Hospital. Previous or current concomitant conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), corticosteroids, number of previous biologic agents, withdrawal, and time intervals of rituximab retreatment were collected. In case of treatment failure, the reasons such as lack of efficacy, adverse events, and others, were also identified. A total of 82 patients were enrolled. The mean follow-up period from the first cycle of rituximab was 46.1 months, and the mean interval between the retreatment courses was 16.3 months. The persistent rates of rituximab after 5 years was 72.4%. Concomitant use of at least two csDMARDs (β = 4.672; 95% CI: 0.089-9.255, p = 0.046) and concomitant use of corticosteroids (β = 7.602; 95% CI: 0.924-14.28, p = 0.026) were independent factors for extending the time interval between the retreatment courses. In conclusion, RA patients treated with rituximab in Korea show high persistence rates. Concomitant use of two or more csDMARDs and concomitant use of corticosteroids with rituximab are associating factors of extending the retreatment time interval. These findings should be considered when selecting rituximab as a treatment for patients with RA.

Rituximab plus leflunomide in rheumatoid arthritis: a randomized, placebo-controlled, investigator-initiated clinical trial (AMARA study)

OBJECTIVE

To investigate the efficacy and safety of rituximab + LEF in patients with RA.

METHODS

In this investigator-initiated, randomized, double-blind, placebo-controlled phase 3 trial, patients with an inadequate response to LEF who had failed one or more DMARD were randomly assigned 2:1 to i.v. rituximab 1000 mg or placebo on day 1 and 15 plus ongoing oral LEF. The primary efficacy outcome was the difference between ≥50% improvement in ACR criteria (ACR50 response) rates at week 24 (P ≤ 0.025). Secondary endpoints included ACR20/70 responses, ACR50 responses at earlier timepoints and adverse event (AE) rates. The planned sample size was not achieved due to events beyond the investigators' control.

RESULTS

Between 13 August 2010 and 28 January 2015, 140 patients received rituximab (n = 93) or placebo (n = 47) plus ongoing LEF. Rituximab + LEF resulted in an increase in the ACR50 response rate that was significant at week 16 (32 vs 15%; P = 0.020), but not week 24 (27 vs 15%; P = 0.081), the primary endpoint. Significant differences favouring the rituximab + LEF arm were observed in some secondary endpoints, including ACR20 rates from weeks 12 to 24. The rituximab and placebo arms had similar AE rates (71 vs 70%), but the rituximab arm had a higher rate of serious AEs (SAEs 20 vs 2%), primarily infections and musculoskeletal disorders.

CONCLUSION

The primary endpoint was not reached, but rituximab + LEF demonstrated clinical benefits vs LEF in secondary endpoints. Although generally well tolerated, the combination was associated with additional SAEs and requires monitoring.

TRIAL REGISTRATION

EudraCT: 2009-015950-39; ClinicalTrials.gov: NCT01244958.

Most Appropriate Conventional Disease-Modifying Antirheumatic Drug to Combine With Different Advanced Therapies in Rheumatoid Arthritis: A Systematic Literature Review With Meta-Analysis

OBJECTIVE

In rheumatoid arthritis, the association between advanced therapies (including biologic disease-modifying antirheumatic drugs [DMARDs] and targeted synthetic DMARDs) and methotrexate (MTX) is recommended by international societies. When MTX cannot be used, other conventional synthetic DMARDs (csDMARDs) may be proposed. We aimed to compare the safety and efficacy of MTX and non-MTX csDMARDs in combination with advanced therapies.

METHODS

We systematically searched the literature for studies comparing the effectiveness, retention rate, and safety of MTX versus non-MTX csDMARDs (leflunomide or others) in combination with tumor necrosis factor inhibitors (TNFi), abatacept, rituximab, tocilizumab, and JAK inhibitors. Meta-analysis was performed with RevMan, using an inverse variance approach with fixed or random-effects models. Risk ratios (RRs) and 95% confidence intervals (95% CIs) were estimated.

RESULTS

The literature search revealed 3,842 articles; 41 studies were included for the systematic literature review and 21 for the meta-analysis: 13 with TNFi, 3 with abatacept, and 5 with rituximab. For TNFi, the European Alliance of Associations for Rheumatology (EULAR) response at 6 months was lower for patients receiving non-MTX csDMARDs than for those using MTX (RR 0.93 [95% CI 0.87, 1.0], P = 0.04; n = 3,843; I² = 28%), with a lower retention rate at 12 months. For abatacept, effectiveness and safety were similar between the 2 groups. For rituximab, a good EULAR response was higher with leflunomide than MTX (RR 1.38 [95% CI 1.13, 1.68], P = 0.001; n = 2,078; I² = 0%), with similar adverse event rates. Meta-analysis for tocilizumab or JAK inhibitors could not be performed.

CONCLUSION

The different csDMARDs seem safe and efficient to combine with advanced therapies in RA patients. Although MTX seems slightly superior to other csDMARDs in combination with TNFi, leflunomide might be superior to MTX in combination with rituximab.

Factors associated with long-term persistence of rituximab in rheumatoid arthritis In clinical practice: RITAR Study

BACKGROUND AND OBJECTIVE

Treatment of rheumatoid arthritis with rituximab (RTX) requires repeated cycles, but there is no well-established retreatment regimen in dose and frequency. The objective was to analyse the persistence of RTX treatment and factors that influence in terms of routine clinical practice.

METHODS

Rituximab in Rheumatoid Arthritis (RITAR Study) is an observational, retrospective study that analyses the persistence of RTX in a cohort from 2003 to 2015. Persistence was calculated by the Kaplan-Meier analysis; curves were compared with the Log-Rank test. Cox regression was used to quantify the risk of discontinuation and multivariate analyses were conducted to determine the factors associated with the persistence of the treatment.

RESULTS

454 cycles of RTX in 114 patients were included. Median survival was 10.0 years and incidence rate of discontinuation was 7.7 per 100 patients/year. Factors associated with persistence were autoantibody positivity and use of RTX in combination with csDMARDs. Sex, age, number of comorbidities, rheumatoid arthritis evolution, number of complications, basal DAS28, basal HAQ, number of lines of treatment, fixed or on demand retreatment and year of RTX starting were not associated. Multivariable models confirmed the relationship between autoantibody positivity, monotherapy and persistence of RTX.

CONCLUSIONS

The persistence of RTX in clinical practice is higher in seropositive patients and in those who are treated with RTX associated with a csDMARD. Dose per cycle and retreatment frequency do not have a decisive role in rituximab persistence.

Experience With the Use of Rituximab for the Treatment of Rheumatoid Arthritis in a Tertiary Hospital in Spain: RITAR Study

Supplemental digital content is available in the text.

There is evidence supporting that there are no relevant clinical differences between dosing rituximab 1000 mg or 2000 mg per cycle in rheumatoid arthritis (RA) patients in clinical trials, and low-dose cycles seem to have a better safety profile. Our objective was to describe the pattern of use of rituximab in real-life practice conditions.

Abatacept used in combination with non-methotrexate disease-modifying antirheumatic drugs: a descriptive analysis of data from interventional trials and the real-world setting

Background

Methotrexate (MTX) remains the anchor drug in rheumatoid arthritis (RA) treatment, but is poorly tolerated or contraindicated in some patients. There is a wealth of data supporting the use of abatacept in combination with MTX, but data on alternative conventional synthetic disease-modifying antirheumatic drug (csDMARD) combinations with abatacept are scarce.

Methods

In this post-hoc exploratory analysis, efficacy and safety data were extracted from abatacept RA studies in which combination with csDMARDs other than MTX was permitted: three interventional trials (ATTAIN, ASSURE, and ARRIVE) and one real-world study (ACTION). Patients with moderate-to-severe RA received abatacept in combination with MTX, hydroxychloroquine, sulfasalazine, azathioprine, or leflunomide for 6 months to 2 years according to the study design. Change from baseline in physical function (Health Assessment Questionnaire—Disability Index (HAQ-DI); all studies) and 28-joint Disease Activity Score (C-reactive protein) (DAS28 (CRP); ATTAIN, ARRIVE, and ACTION), American College of Rheumatology response rates (ATTAIN), and safety were assessed for individual and pooled csDMARD combinations for each trial. A meta-analysis was also performed on pooled data for HAQ-DI and DAS28 (CRP) across interventional trials.

Results

Across all four studies, 731 patients received abatacept plus one non-MTX csDMARD (hydroxychloroquine n = 152; sulfasalazine n = 123; azathioprine n = 59; and leflunomide n = 397) and 2382 patients received abatacept plus MTX. Mean changes from baseline in HAQ-DI scores for abatacept plus MTX (all csDMARDs pooled) vs abatacept plus a non-MTX csDMARD were –0.54 vs –0.44 (ATTAIN), –0.43 vs –0.43 (ASSURE), and –0.39 vs –0.36 (ARRIVE). Mean changes from baseline in DAS28 (CRP) and ACR response rates were also similar with abatacept plus MTX or non-MTX csDMARDs. Data for individual non-MTX csDMARDs (pooled across studies) and real-world data were consistent with these findings. Rates of treatment-related adverse events and serious adverse events, respectively, for abatacept plus one non-MTX csDMARD vs abatacept plus MTX were 35.7% vs 41.7% and 2.4% vs 2.3% (ATTAIN), 58.0% vs 55.9% and 4.2% vs 1.7% (ASSURE), and 38.1% vs 44.3% and 0.6% vs 2.9% (ARRIVE).

Conclusions

Abatacept in combination with non-MTX csDMARDs is clinically effective and well tolerated in patients with moderate-to-severe RA, providing similar benefits to those seen with abatacept plus MTX.

Trial registration

ClinicalTrials.gov NCT00048581. Registered 2 November 2002.

ClinicalTrials.gov NCT00048932. Registered 11 November 2002.

ClinicalTrials.gov NCT00124982. Registered 30 June 2005.

ClinicalTrials.gov NCT02109666. Registered 8 April 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1488-5) contains supplementary material, which is available to authorized users.

Proteome Analysis of Rheumatoid Arthritis Gut Mucosa

Rheumatoid arthritis (RA) is an inflammatory joint disease leading to cartilage damage and ultimately impaired joint function. To gain new insight into the systemic immune manifestations of RA, we characterized the colon mucosa proteome from 11 RA-patients and 10 healthy controls. The biopsies were extracted by colonoscopy and analyzed by label-free quantitative proteomics, enabling the quantitation of 5366 proteins. The abundance of dihydrofolate reductase (DHFR) was statistically significantly increased in RA-patient biopsies compared with controls and correlated with the administered dosage of methotrexate (MTX), the most frequently prescribed immunosuppressive drug for RA. Additionally, our data suggest that treatment with Leflunomide, a common alternative to MTX, increases DHFR. The findings were supported by immunohistochemistry with confocal microscopy, which furthermore demonstrated that DHFR was located in the cytosol of the intestinal epithelial and interstitial cells. Finally, we identified 223 citrullinated peptides from 121 proteins. Three of the peptides were unique to RA. The list of citrullinated proteins was enriched in extracellular and membrane proteins and included known targets of anticitrullinated protein antibodies (ACPAs). Our findings support that the colon mucosa could trigger the production of ACPAs, which could contribute to the onset of RA. The MS data have been deposited to ProteomeXchange with identifiers PXD001608 and PXD003082.

High remission and low relapse with prolonged intensive DMARD therapy in rheumatoid arthritis (PRINT): A multicenter randomized clinical trial

OBJECTIVES

To determine whether prolonged intensive disease-modifying antirheumatic drug (DMARD) treatment (PRINT) leads to high remission and low relapse rates in patients with severe rheumatoid arthritis (RA).

METHODS

In this multicenter, randomized and parallel treatment trial, 346 patients with active RA (disease activity score (28 joints) [DAS28] (erythrocyte sedimentation rate [ESR]) > 5.1) were enrolled from 9 centers. In phase 1, patients received intensive treatment with methotrexate, leflunomide, and hydroxychloroquine, up to 36 weeks, until remission (DAS28 ≤ 2.6) or a low disease activity (2.6 < DAS28 ≤ 3.2) was achieved. In phase 2, patients achieving remission or low disease activity were followed up with randomization to 1 of 2 step-down protocols: leflunomide plus hydroxychloroquine combination or leflunomide monotherapy. The primary endpoints were good European League Against Rheumatism (EULAR) response (DAS28 (ESR) < 3.2 and a decrease of DAS28 by at least 1.2) during the intensive treatment and the disease state retention rate during step-down maintenance treatment. Predictors of a good EULAR response in the intensive treatment period and disease flare in the maintenance period were sought.

RESULTS

A good EULAR response was achieved in 18.7%, 36.9%, and 54.1% of patients at 12, 24, and 36 weeks, respectively. By 36 weeks, 75.4% of patients achieved good and moderate EULAR responses. Compared with those achieving low disease activity and a high health assessment questionnaire (HAQ > 0.5), patients achieving remission (DAS28 ≤ 2.6) and low HAQ (≤ 0.5) had a significantly higher retention rate when tapering the DMARDs treatment (P = 0.046 and P = 0.01, respectively). There was no advantage on tapering to combination rather than monotherapy.

CONCLUSIONS

Remission was achieved in a proportion of patients with RA receiving prolonged intensive DMARD therapy. Low disease activity at the start of disease taper leads to less subsequent flares. Leflunomide is a good maintenance treatment as single treatment.

Comparative effectiveness of tocilizumab with either methotrexate or leflunomide in the treatment of rheumatoid arthritis

OBJECTIVE

In agreement with EULAR recommendations, a DMARD in combination with a biotherapy is the reference treatment because of the superior long-term clinical and radiographic outcomes. Methotrexate (MTX) is the cornerstone of combination therapy but is in some cases contra-indicated or poorly tolerated. This observational study aimed to compare the effectiveness and safety of TCZ in combination with either MTX or leflunomide (LEF) in the treatment of patients with active rheumatoid arthritis (RA) and an inadequate response to one or more DMARDs and/or biological agents in a real-world setting.

METHODS

We performed an ambispective review of 91 patients with active RA who were routinely treated with TCZ plus MTX or LEF. A comparative study between the two combinations of treatment was performed at 6 months of follow-up considering 3 outcomes: improvement of RA disease activity, evolution of functional disability, and tolerability and side effect profile.

RESULTS

Of the 91 patients, 62 received TCZ with MTX and 29 received TCZ with LEF. Eighty-one patients were followed for 6 months, and the remaining 10 patients discontinued treatment due to serious adverse events. At baseline, there were no significant differences between the groups in terms of the main clinical and laboratory data or in the number of previous DMARDs and biological agents used. At 6 months, there were no significant differences between the combinations in terms of disease activity and functional disability. Serious adverse events occurred in 11% and 10% of the patients treated in combination with MTX and LEF, respectively.

CONCLUSION

Our preliminary data support the argument that LEF is an effective and safe (equivalent) alternative to MTX for combination treatment with TCZ.

Sustainability of rituximab therapy in different treatment strategies: results of a 3-year followup of a German biologics register

OBJECTIVE

To compare the approved treatment of rheumatoid arthritis using rituximab + methotrexate (RTX + MTX) versus the off-label treatment variants of RTX in monotherapy or RTX in combination with leflunomide (RTX + LEF).

METHODS

We included RTX-naive patients enrolled in the German biologics register RABBIT (Rheumatoid Arthritis: Observation of Biologic Therapy) between 2007 and 2012 (n = 907) who started treatment with RTX. Three treatment regimens (RTX + MTX, RTX + LEF, and RTX monotherapy) were analyzed regarding therapy discontinuation, dropout, RTX retreatment, and concomitant glucocorticoid therapy. Effectiveness was evaluated with linear mixed models.

RESULTS

Baseline patient characteristics were similar across treatment regimens, except for poorer functional status and more comorbidities in RTX monotherapy. Average doses of glucocorticoids were lower in RTX + LEF compared to the 2 other groups. The frequency and timing of RTX retreatment (P > 0.62) as well as improvement in the Disease Activity Score in 28 joints (DAS28) over time (P > 0.15) were similar in all treatment regimens. Within the first 12 months of treatment, the DAS28 decreased by 1.5 units, and between months 12 and 36, by a further 0.4 unit equally in all groups. Nevertheless, therapy discontinuation and dropout were significantly increased on RTX monotherapy (hazard ratio [HR] 1.7 [95% confidence interval (95% CI) 1.2-2.3]), and additionally when patients were rheumatoid factor negative (HR 1.5 [95% CI 1.0-2.1]).

CONCLUSION

In patients who continue therapy, RTX + LEF, RTX monotherapy, and RTX + MTX seem to be equally effective. However, given the lower adherence rates on monotherapy, this treatment option is not sufficient for all patients. Since many patients are intolerant to MTX, more licensed RTX treatment options are needed.

Current immunotherapy in rheumatoid arthritis

Rheumatoid arthritis is a common autoimmune disease primarily manifesting as chronic synovitis, subsequently leading to a change in joint integrity. Progressive disability and systemic complications are strongly associated with a decreased quality of life. To maintain function and health in patients with rheumatoid arthritis, early, aggressive and guided immunosuppressive therapy is required to induce clinical remission. Antirheumatic drugs are capable of controlling synovial inflammation and are therefore named 'disease-modifying antirheumatic drugs' (DMARDs). This article aims to bridge the beginning of DMARD therapy with agents such as methotrexate, leflunomide, sulfasalazine, injectable gold and (hydroxy)chloroquine with biological therapies, and with the new era of kinase inhibitors. Mechanisms of action, as well as advantages and disadvantages of DMARDs, are discussed with respect to the current literature and current recommendations.