Severe Refractory Rheumatoid Arthritis Successfully Treated with Combination Rituximab and Anti-Tumor Necrosis Factor-α-Blocking Agents

Rationale, current state and opportunities in combining biologic disease modifying antirheumatic drugs in rheumatoid and psoriatic arthritis

The advent of biologic disease modifying antirheumatic drugs (bDMARDs) has considerably improved patient outcomes in inflammatory arthritis. However, not all patients reach the state of remission, as disease can be resistant even to single cytokine inhibition by bDMARDs. Simultaneous or sequential inhibition of multiple cytokines may be considered in situations where disease control is not adequate under singular inhibition of cytokines. Although there have been some disappointing experiences in the past with combination of bDMARDs, the ongoing improvement of our understanding about inflammatory pathways and the overall better safety understanding of bDMARDs seem to make new biologic treatment combinations possible. This review covers the rationale and current evidence for bDMARDs combination in inflammatory arthritis.

Summarizing current refractory disease definitions in rheumatoid arthritis and polyarticular juvenile idiopathic arthritis: systematic review

OBJECTIVES

To identify how refractory disease (or relevant terminology variations) in RA and polyarticular JIA (polyJIA) is defined and establish the key components of such definitions.

METHODS

Searches were undertaken of English-language articles within six medical databases, including manual searching, from January 1998 to March 2020 (PROSPERO: CRD42019127142). Articles were included if they incorporated a definition of refractory disease, or non-response, in RA/polyJIA, with clear components to the description. Qualitative content analysis was undertaken to describe refractory disease in RA/polyJIA and classify each component within each definition.

RESULTS

Of 6251 studies screened, 646 met the inclusion criteria; 581 of these applied non-response criteria while 65 provided refractory disease definitions/descriptions. From the non-response studies, 39 different components included various disease activity measures, emphasizing persistent disease activity and symptoms, despite treatment with one or more biologic DMARD (bDMARD). From papers with clear definitions for refractory disease, 41 components were identified and categorized into three key themes: resistance to multiple drugs with different mechanisms of action, typically two or more bDMARDs; persistence of symptoms and disease activity; and other contributing factors. The most common term used was 'refractory' (80%), while only 16.9% reported explicitly how their definition was generated (e.g. clinical experience or statistical methods).

CONCLUSION

Refractory disease is defined as resistance to multiple drugs with different mechanisms of action by persistence of physical symptoms and high disease activity, including contributing factors. A clear unifying definition needs implementing, as the plethora of different definitions makes study comparisons and appropriate identification of patients difficult.

Combining Biologics in Inflammatory Bowel Disease and Other Immune Mediated Inflammatory Disorders

Current therapies used in the treatment of inflammatory bowel disease (IBD) are not effective in all patients. Biologic agents result in approximately 40% remission rates at 1 year in selected populations, prompting a growing interest in combining biologic therapy to improve outcomes. There are limited published data regarding the efficacy and safety of combination targeted therapy in IBD specifically, which include only 1 exploratory randomized control trial and 3 case reports or series. This review evaluates the published literature regarding this therapeutic paradigm in IBD and its extensive utilization in the treatment of other immune-mediated inflammatory disorders. The combination of biologic therapies demonstrates variable degrees of efficacy and highlights some safety concerns, depending upon the agents used and the disease state treated. A trial (Clinical Trials.gov Identifier: NCT02764762) combining vedolizumab and adalimumab is currently underway evaluating the effectiveness and safety of this approach in patients with Crohn's disease, which should provide further insight into this treatment concept. While combination biologic therapy is an attractive strategy, the lack of consistent superior efficacy as well as safety concerns militates the need for further trials prior to its general application in IBD.

[Combination of biologics : where do we stand?]

INTRODUCTION

Data with respect to safety and therapeutic efficacy for the combination of biological DMARDs is scarce and inhomogeneous in order to make final conclusions. To this end, data to biologic combinations is disappointing due to relatively low therapeutic efficacy and partially enhanced rates of severe infectious events.

METHODS

Combining biologics is an option only in very special situations (RTX plus TNFi). In addition, the relation of financial effort to therapeutic efficacy is questionable, especially in the situation of numerous drug options (anti-cytokine principle, T-cell inhibition, B-cell depletion) and therapeutic strategies of combining biologics with DMARDs. Generally speaking, combinations of biological should only be used in clinical trials. New drugs influencing intracellular signaling pathways (small molecules) are going to be approved or are already approved by the drug agencies, thus, adding to the existing armamentarium. Furthermore, combinations with these new molecules are going to be interesting.

CONCLUSIONS

This review summarizes the available studies concerning combination of biologicals in a tabular fashion.

Detection and isolation of auto-reactive human antibodies from primary B cells

The isolation of human monoclonal antibodies (hmAb) has emerged as a versatile platform in a wide variety of contexts ranging from vaccinology to therapeutics. In particular, the presence of high titers of circulating auto-antibodies is implicated in the pathology and outcome of autoimmune diseases. Therefore, the molecular characterization of these hmAb provides an avenue to understanding the pathogenesis of autoimmune diseases. Additionally, the phenotype of the auto-reactive B cells may have direct relevance for therapeutic intervention. In this report, we describe a high-throughput single-cell assay, microengraving, for the screening, characterization and isolation of anti-citrullinated protein antibodies (ACPA) from peripheral blood mononuclear cells (PBMC) of rheumatoid arthritis (RA) patients. Stimulated B cells are profiled at the single-cell level in a large array of sub-nanoliter nanowells (∼10(5)), assessing both the phenotype of the cells and their ability to secrete cyclic-citrullinated peptide (CCP)-specific antibodies. Single B cells secreting ACPA are retrieved by automated micromanipulation, and amplification of the immunoglobulin (Ig) heavy and light chains is performed prior to recombinant expression. The methodology offers a simple, rapid and low-cost platform for isolation of auto-reactive antibodies from low numbers of input cells and can be easily adapted for isolation and characterization of auto-reactive antibodies in other autoimmune diseases.

Etanercept for the treatment of rheumatoid arthritis

BACKGROUND

Etanercept is a soluble tumour necrosis factor alpha-receptor disease-modifying anti-rheumatic drug (DMARD) for the treatment of rheumatoid arthritis (RA).

OBJECTIVES

The purpose of this review was to update the previous Cochrane systematic review published in 2003 assessing the benefits and harms of etanercept for the treatment of RA. In addition, we also evaluated the benefits and harms of etanercept plus DMARD compared with DMARD monotherapy in those people with RA who are partial responders to methotrexate (MTX) or any other traditional DMARD.

SEARCH METHODS

Five electronic databases were searched from 1966 to February 2003 with no language restriction. The search was updated to January 2012. Attempts were made to identify other studies by contact with experts, searching reference lists and searching trial registers.

SELECTION CRITERIA

All controlled trials (minimum 24 weeks' duration) comparing four possible combinations: 1) etanercept (10 mg or 25 mg twice weekly) plus a traditional DMARD (either MTX or sulphasalazine) versus a DMARD, 2) etanercept plus DMARD versus etanercept alone, 3) etanercept alone versus a DMARD or 4) etanercept versus placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of the trials.

MAIN RESULTS

Three trials were included in the original version of the review. An additional six trials, giving a total of 2842 participants, were added to the 2012 update of the review. The trials were generally of moderate to low risk of bias, the majority funded by pharmaceutical companies. Follow-up ranged from six months to 36 months.BenefitAt six to 36 months the American College of Rheumatology (ACR) 50 response rate was statistically significantly improved with etanercept plus DMARD treatment when compared with a DMARD in those people who had an inadequate response to any traditional DMARD (risk ratio (RR) 2.0; 95% confidence interval (CI) 1.3 to 2.9, absolute treatment benefit (ATB) 38%; 95% CI 13% to 59%) and in those people who were partial responders to MTX (RR 11.7; 95% CI 1.7 to 82.5, ATB 36%). Similar results were observed when pooling data from all participants (responders or not) (ACR 50 response rates at 24 months: RR 1.9; 95% CI 1.3 to 2.8, ATB 29%; 36 months: RR 1.6; 95% CI 1.3 to 1.9, ATB 24%). Statistically significant improvement in physical function and a higher proportion of disease remission were observed in combination-treated participants compared with DMARDs alone ((mean difference (MD) -0.36; 95% CI -0.43 to -0.28 in a 0-3 scale) and (RR 1.92; 95% CI 1.60 to 2.31), respectively) in those people who had an inadequate response to any traditional DMARD. All changes in radiographic scores were statistically significantly less with combination treatment (etanercept plus DMARD) compared with MTX alone for all participants (responders or not) (Total Sharp Score (TSS) (scale = 0 to 448): MD -2.2, 95% CI -3.0 to -1.4; Erosion Score (ES) (scale = 0 to 280): MD -1.6; 95% CI -2.4 to -0.9; Joint Space Narrowing Score (JSNS) (scale = 0 to 168): MD -0.7; 95% CI -1.1 to -0.2), and with combination treatment compared with etanercept alone (TSS: MD -1.1; 95% CI -1.8 to -0.5; ES: MD -0.7; 95% CI -1.1 to -0.2; JSNS: MD -0.5, 95% CI -0.7 to -0.2). The estimate of irreversible physical disability over 10 years given the radiographic findings was 0.45 out of 3.0.When etanercept monotherapy was compared with DMARD monotherapy, there was generally no evidence of a difference in ACR50 response rates when etanercept 10 mg or 25 mg was used; at six months etanercept 25 mg was significantly more likely to achieve ACR50 than DMARD monotherapy but this difference was not found at 12, 24 or 36 months. TSS and ES radiographic scores were statistically significantly improved with etanercept 25 mg monotherapy compared with DMARD (TSS: MD -0.7; 95% CI -1.4 to 0.1; ES: MD -0.7; 95% CI -1.0 to -0.3) but there was no evidence of a statistically significant difference between etanercept 10 mg monotherapy and MTX.HarmsThere was no evidence of statistically significant differences in infections or serious infections between etanercept plus DMARD and DMARD alone at any point in time. Infection rates were higher in people receiving etanercept monotherapy compared with DMARD; however, there were no differences regarding serious infections. For those participants who had an inadequate response to DMARDs, the rate of total withdrawals was lower for the etanercept plus DMARD group compared with DMARD alone (RR 0.53; 95% CI 0.36 to 0.77, ATB 18%). No other statistically significant differences were observed in any of the assessed comparisons.

AUTHORS' CONCLUSIONS

Etanercept 25 mg administered subcutaneously twice weekly together with MTX was more efficacious than either etanercept or MTX monotherapy for ACR50 and it slowed joint radiographic progression after up to three years of treatment for all participants (responders or not). There was no evidence of a difference in the rates of infections between groups.

Evaluation of the safety of rituximab in combination with a tumor necrosis factor inhibitor and methotrexate in patients with active rheumatoid arthritis: results from a randomized controlled trial

OBJECTIVE

To assess the safety of rituximab in combination with a tumor necrosis factor (TNF) inhibitor and methotrexate (MTX) in patients with rheumatoid arthritis (RA).

METHODS

Adult patients with active RA (≥ 5 swollen and ≥ 5 tender joints) receiving a stable dose of MTX (10-25 mg/week) and stable dose of TNF inhibitor (etanercept or adalimumab) for ≥ 12 weeks were randomized 2:1 to receive one course of rituximab or placebo, given intravenously at a dose of 2 × 500 mg. The primary end point was the proportion of patients developing ≥ 1 serious infection through week 24.

RESULTS

Fifty-one patients were treated with either rituximab or placebo in combination with background MTX and a TNF inhibitor. Baseline characteristics were generally balanced between groups, except for corticosteroid usage (36% in the rituximab arm versus 17% in the placebo arm). A serious infection (pneumonia) was observed in 1 patient (3%) in the rituximab group after 14.4 patient-years of exposure (6.95 events per 100 patient-years, 95% confidence interval 0.98-49.35), compared with none in the placebo group at week 24. Infections were reported in 18 patients (55%) and 11 patients (61%) in the rituximab and placebo groups, respectively. Grade 3 infections were reported in 3 patients (9%) receiving rituximab and in none of the patients receiving placebo. No grade 4 infections were observed, nor were there any opportunistic, fungal, or tuberculosis infections. Serious adverse events (SAEs) were reported in 2 rituximab-treated patients (pneumonia and coronary artery occlusion), whereas there were no SAEs reported in placebo-treated patients. At week 24, the percentage of patients achieving an American College of Rheumatology 20% (ACR20) improvement response was 30% in the rituximab group compared with 17% in the placebo group, and ACR50 responses were achieved by 12% and 6% of patients, respectively.

CONCLUSION

The preliminary safety profile of rituximab in combination with a TNF inhibitor and MTX was consistent with the safety profile of rituximab in combination with MTX in other RA trials without a TNF inhibitor, with no new safety signals observed. SAEs were numerically more frequent in the rituximab group, and there was no clear evidence of an efficacy advantage in patients receiving rituximab in combination with a TNF inhibitor and MTX.