Methotrexate as combination partner of TNF inhibitors and tocilizumab. What is reasonable from an immunological viewpoint?

Helicobacter pylori and rheumatoid arthritis: Investigation of relation from traditional Chinese medicine

Rheumatoid arthritis (RA) is an autoimmune condition that predominantly affects synovial joints, manifesting with joint swelling, pain, and stiffness. In advanced stages, unchecked inflammation can inflict damage on bone and cartilage, resulting in disabilities and deformities of the joints. Additionally, systemic and extra-articular complications may arise due to the consequences of uncontrolled inflammation. Helicobacter pylori (H. pylori) is one of the most prevalent chronic bacterial infections in humans. This microorganism is a spiral-shaped, flagellated, microaerophilic gram-negative bacterium. Prolonged exposure leads to the activation of the immune system, with infected gastric mucosa epithelial cells continuously producing cytokines. This production, in turn, triggers the generation of antibodies as well as T Helper 1 and T Helper 2 effector T cells. The persistent antigenic stimulation resulting from H. pylori infection could lead to the progression of autoimmune diseases. Numerous clinical and pharmacological trials have illustrated the efficacy of traditional Chinese medicine against H. pylori. This review aims to delve into the connection between H. pylori and rheumatoid arthritis so as understand the pathogenesis. The concluding section of this review explores the interplay of Chinese medicine and Helicobacter pylori concerning rheumatoid arthritis.

The impact of the human gut microbiome on the treatment of autoimmune disease

Autoimmune (or rheumatic) diseases are increasing in prevalence but selecting the best therapy for each patient proceeds in trial-and-error fashion. This strategy can lead to ineffective therapy resulting in irreversible damage and suffering; thus, there is a need to bring the promise of precision medicine to patients with autoimmune disease. While host factors partially determine the therapeutic response to immunosuppressive drugs, these are not routinely used to tailor therapy. Thus, non-host factors likely contribute. Here, we consider the impact of the human gut microbiome in the treatment of autoimmunity. We propose that the gut microbiome can be manipulated to improve therapy and to derive greater benefit from existing therapies. We focus on the mechanisms by which the human gut microbiome impacts treatment response, provide a framework to interrogate these mechanisms, review a case study of a widely-used anti-rheumatic drug, and discuss challenges with studying multiple complex systems: the microbiome, the human immune system, and autoimmune disease. We consider open questions that remain in the field and speculate on the future of drug-microbiome-autoimmune disease interactions. Finally, we present a blue-sky vision for how the microbiome can be used to bring the promise of precision medicine to patients with rheumatic disease.

Plasma TNF-α Elevation in Biologic Naive Rheumatoid Arthritis Patients Belonging to a Population with New Mutations in TLR4 and CYP51A1 genes without Association with Disease-Related Antibodies Levels

In a system biology-based study, we previously reported that IL-6 and IL6R -specific m-RNA levels were elevated in leukocytes of patients with Rheumatoid arthritis (RA). Here, the association of toll-like receptor4 (TLR4) rs 141534085 and cytochrome P450 family 51 subfamily A member 1(CYP51A1) rs6 with tumor necrosis factor-α (TNF- α), rheumatoid factor (RF)- and Anti- cyclic citrullinated peptide (anti-CCP) antibody -positivity was investigated in almost the same subjects. Forty-six patients and 48 normal subjects were recruited in this study. The blood leucocytes TLR4 rs 141534085 and CYP51A1 rs6 -comprising DNA sequences were amplified by using tetra-primer amplification refractory mutation system polymerase chain reaction (T-ARMS-PCR) technique and the PCR products were checked by Sanger DNA sequencing method. ELISA method was used to determine plasma levels of TNF- α, anti-CCP antibody and RF positivity of plasma was evaluated through a latex agglutination test. The TNF- α level was significantly higher in the patient group than control subjects (p= 0.001). Moreover, we were not able to find any correlation between TNF-α levels and RF as well as anti-CCP antibodies when we used the K2/ Fisher's exact test and Pearson test respectively. Our DNA sequencing data revealed the following new mutations in TLR4 rs141534085 comprising regions: A>T in position 1050, T>A in position 1052, and C>A in position 1054; and for CYP51A1 rs6 encompassing region, the new mutations were; G>A in position 21680, the T nucleotide was inserted in position 21762 and the G nucleotide was inserted in position 21763, G>T in position 21764. The data of this study showed that both TLR4 rs141534085 and CYP51A1 rs6 related DNA regions should be considered as hotspot areas in RA pathogenicity. Moreover, these data indicated that, TNF- α did not alter the production of anti-CCP and RF pathogenic antibodies in patients with long-term RA.

[Drug therapy of rheumatoid arthritis: where do biologics and novel synthetic disease-modifying antirheumatic drugs stand today?]

Biologics and Janus kinase (JAK) inhibitors play an important role in the treatment of rheumatoid arthritis. As new therapeutic developments have emerged in recent decades, the morbidity and mortality of rheumatoid arthritis have been significantly reduced. The characterization of the structure and function of immune cell receptors has led to the development of biologics that specifically inhibit cytokines and immune cell receptors. An important therapeutic addition was the approval of JAK inhibitors, which act directly on intracellular signaling by tyrosine kinases. This article provides an overview of the current therapeutic options for rheumatoid arthritis with a special focus on indication, mechanism of action and the place in the treatment algorithm of biologics and JAK inhibitors.

An Overview of PDE4 Inhibitors in Clinical Trials: 2010 to Early 2022

Since the early 1980s, phosphodiesterase 4 (PDE4) has been an attractive target for the treatment of inflammation-based diseases. Several scientific advancements, by both academia and pharmaceutical companies, have enabled the identification of many synthetic ligands for this target, along with the acquisition of precise information on biological requirements and linked therapeutic opportunities. The transition from pre-clinical to clinical phase was not easy for the majority of these compounds, mainly due to their significant side effects, and it took almost thirty years for a PDE4 inhibitor to become a drug i.e., Roflumilast, used in the clinics for the treatment of chronic obstructive pulmonary disease. Since then, three additional compounds have reached the market a few years later: Crisaborole for atopic dermatitis, Apremilast for psoriatic arthritis and Ibudilast for Krabbe disease. The aim of this review is to provide an overview of the compounds that have reached clinical trials in the last ten years, with a focus on those most recently developed for respiratory, skin and neurological disorders.

Potential long-term effect of tumor necrosis factor inhibitors on dementia risk: A propensity score matched retrospective cohort study in US veterans

INTRODUCTION

Tumor necrosis factor (TNF) inhibitors are widely used to treat rheumatoid arthritis (RA) and their potential to retard Alzheimer's disease (AD) progression has been reported. However, their long-term effects on the dementia/AD risk remain unknown.

METHODS

A propensity scored matched retrospective cohort study was conducted among 40,207 patients with RA within the US Veterans Affairs health-care system from 2000 to 2020.

RESULTS

A total of 2510 patients with RA prescribed TNF inhibitors were 1:2 matched to control patients. TNF inhibitor use was associated with reduced dementia risk (hazard ratio [HR]: 0.64, 95% confidence interval [CI]: 0.52-0.80), which was consistent as the study period increased from 5 to 20 years after RA diagnosis. TNF inhibitor use also showed a long-term effect in reducing the risk of AD (HR: 0.57, 95% CI: 0.39-0.83) during the 20 years of follow-up.

CONCLUSION

TNF inhibitor use is associated with lower long-term risk of dementia/AD among US veterans with RA.

Reduced Humoral Response of SARS-CoV-2 Antibodies following Vaccination in Patients with Inflammatory Rheumatic Diseases-An Interim Report from a Danish Prospective Cohort Study

Background/Purpose: In light of the current COVID-19 pandemic, whether patients with rheumatic musculoskeletal disease (RMD) treated with conventional (cs) or biologic (b) disease-modifying drugs (DMARDs) exhibit an adequate immune response to the currently available SARS-CoV-2 vaccinations remains a major concern. There is an urgent need for more SARS-CoV-2 vaccine efficacy data to inform healthcare providers on the potential need for a booster vaccine. We established the ‘Detection of SARS-CoV-2 antibodies in Danish Inflammatory Rheumatic Outpatients’ study (DECODIR) in March 2021 in order to assess and compare the immunoglobulin G (IgG response) of the SARS-CoV-2 BNT162b2 vaccine (Pfizer, Groton, CT, USA/BioNTech, Mainz, Germany) and mRNA-1273 vaccine (Moderna, Cambridge, MA, USA) administered as part of the national vaccine roll out in patients with RMDs, irrespective of treatment. Patients’ SARS-CoV-2 IgG level was used as proxy to determine vaccination response. Methods: The study is a longitudinal prospective cohort study in which the SARS-CoV-2 antibody response was measured and compared at baseline and at six weeks following vaccination. The study population consisted of patients with rheumatoid arthritis (RA), spondyloarthropathies (SpA), or psoriatic arthritis (PsA) receiving their outpatient treatment at the Danish Hospital for Rheumatic Diseases, Sonderborg. Bloods, patient reported outcome measurements (PROMS), clinical data, and treatment information (cs/bDMARD) were collected at baseline/6 weeks and documented in the Danish DANBIO registry. Commercially available antibody tests (ThermoFisher, Waltham, MA, USA) were used, and SARS-CoV-2 IgG levels were reported in EliA U/mL. Sufficient IgG response was defined as ≥10 EliA U/mL (manufacturers cut-off). Associations between antibody response, age, gender, disease (RA/PsA/SpA), no treatment or cs/bDMARD treatment, and disease activity were tested using proportional odds regression and bootstrapped tests of medians. Results were reported using mean, median (IqR), and bootstrapped 95% confidence interval (CI) of the median. Results: A total of 243 patients were included. We observed a significant increase in IgG levels (median of <0.7 EliA U/mL at baseline versus 34.5 EliA U/mL at 6 weeks). Seventy-two patients (32%) had an insufficient IgG response. The median IgG level in patients treated with cs/bDMARD combination therapy was significantly lower compared to patients without any DMARD treatment (12 EliA U/mL vs. 92 EilA U/mL (p < 0.01)). Conclusion: Patients treated with a combination of cs/bDMARD are at significantly higher risk of an inadequate response to SARS-CoV-2 vaccines as measured by IgG level compared to patients without DMARD treatment. IgG SARS-CoV-2 are only part of the immune response, and further data are urgently needed. At present, our results may inform healthcare providers and policy makers on the decision for the need of a booster vaccine in this particular patient group.

Analysis of the Immunogenicity from Abatacept-Treated Pediatric Patients With Polyarticular-Course Juvenile Idiopathic Arthritis: Findings From Two Phase III Clinical Trials

Objective

The goal of this article is to present the analysis of anti‐abatacept antibody data from children with polyarticular‐course juvenile idiopathic arthritis (pJIA), treated with abatacept. The data are from 395 participants with pJIA from two abatacept registrational trials.

Methods

We analyzed immunogenicity data according to age groups, administration route (intravenous [IV] or subcutaneous [SC]), drug treatment interruption, and co‐medications (with or without methotrexate [MTX]) to assess impact on the incidence of anti‐abatacept antibodies.

Results

The overall immunogenicity incidences observed in both JIA trials ranged between 4.7% and 23.3%. There was a slightly higher immunogenicity incidence in the 2–5‐year‐old participants (15.2%) compared with 6–17‐year‐old participants (4.7%). In the study with SC dosing, the overall incidence on treatment was 2.3% (3% if co‐dosed with MTX), similar to the incidence for Period A of the IV study (similar duration of treatment as the SC study), which was 2.1% (1.4% if co‐dosed with MTX). In the IV study, the period following a 6‐month interruption in treatment had comparable immunogenicity incidences (22.9% with interruption vs. 18.2% without interruption, both co‐dosed with MTX and 0% for both not co‐dosed with MTX). In most cases, participants co‐dosed with MTX had higher immunogenicity incidences than those on abatacept alone.

Conclusion

Although some trends were noted in terms of incidence according to age and MTX co‐dosing, none where conclusive owing to differences in population size. Drug holiday had no impact on immunogenicity incidence once treatment was resumed, and incidences across SC and IV dosing were comparable. There was no impact of immunogenicity on pharmacokinetics, safety, and efficacy.

The Genetic, Environmental, and Immunopathological Complexity of Autoantibody-Negative Rheumatoid Arthritis

Differences in clinical presentation, response to treatment, and long-term outcomes between autoantibody-positive and -negative rheumatoid arthritis (RA) highlight the need for a better comprehension of the immunopathogenic events underlying the two disease subtypes. Whilst the drivers and perpetuators of autoimmunity in autoantibody-positive RA have started to be disclosed, autoantibody-negative RA remains puzzling, also due its wide phenotypic heterogeneity and its possible misdiagnosis. Genetic susceptibility appears to mostly rely on class I HLA genes and a number of yet unidentified non-HLA loci. On the background of such variable genetic predisposition, multiple exogeneous, endogenous, and stochastic factors, some of which are not shared with autoantibody-positive RA, contribute to the onset of the inflammatory cascade. In a proportion of the patients, the immunopathology of synovitis, at least in the initial stages, appears largely myeloid driven, with abundant production of proinflammatory cytokines and only minor involvement of cells of the adaptive immune system. Better understanding of the complexity of autoantibody-negative RA is still needed in order to open new avenues for targeted intervention and improve clinical outcomes.

Methotrexate Reduces the Probability of Discontinuation of TNF Inhibitors in Seropositive Patients With Rheumatoid Arthritis. A Real-World Data Analysis

Tumor necrosis factor inhibitors (TNFi) are widely used for the treatment of patients with rheumatoid arthritis (RA), however a considerable percentage of patients discontinued the therapy. The aim of this study is to explore real-world TNFi survival, stratified for seropositivity, and to determine the factors that may influence it. This is a retrospective, observational and longitudinal study, using real-world data of patients, who started their first TNFi therapy between 1999 and 2018 from the RA-PAZ cohort. Patients were considered seropositive if they showed positive serum levels of either RF, ACPA, or both. Treatment survival was analyzed using Kaplan-Meier curves, and Cox proportional hazards models were used to compare the risks of TNFi discontinuation for seronegative and seropositive patients. Of the included 250 patients, 213 (85%) were seropositive. Results showed that TNFi survival did not depend on seropositivity status. However, median survival time was significant longer for seropositive patients who received concomitant MTX compared to patients who did not receive it (median [95% CI]: 3.3 yr. [2.3-4.2] vs. 2.6 yr. [1.7-3.6], respectively; p = 0.008). Furthermore, seropositive patients who received concomitant MTX were 49% less likely to discontinue TNFi therapy than patients who did not receive it (HR: 0.51; 95% CI: 0.35-0.74). In addition, we found that in seropositive patients, the use of prednisone throughout the TNFi treatment was associated with a higher likelihood of therapy discontinuation (OR: 2.30; 95% CI: 1.01-5.23). In conclusion, these data provide evidence to support the use of concomitant MTX in seropositive patients to prolong the effectiveness and the survival of the TNFi therapy. Moreover, the co-administration of prednisone in seropositive patients receiving TNFi was highly associated with TNFi discontinuation.

Remission Induced by TNF Inhibitors Plus Methotrexate is Associated With Changes in Peripheral Naïve B Cells in Patients With Rheumatoid Arthritis

Biological therapies, such as TNF inhibitors (TNFi), are increasing remission (REM) rates in rheumatoid arthritis (RA) patients, although these are still limited. The aim of our study was to analyze changes in the profile of peripheral blood mononuclear cells (PBMC) in patients with RA treated with TNFi in relation to the clinical response. This is a prospective and observational study including 78 RA patients starting the first TNFi. PBMC were analyzed by flow cytometry both at baseline and at 6 months. Disease activity at the same time points was assessed by DAS28, establishing DAS28 ≤ 2.6 as the criteria for REM. Logistic regression models were employed to analyze the association between the changes in PBMC and REM. After 6 months of TNFi treatment, 37% patients achieved REM by DAS28. Patients who achieved REM showed a reduction in the percentage of naive B cells, but only when patients had received concomitant methotrexate (MTX) (OR: 0.59; 95% CI: 0.39–0.91). However, no association was found for patients who did not receive concomitant MTX (OR: 0.85; 95% CI: 0.63–1.16). In conclusion, PBMC, mainly the B-cell subsets, are modified in RA patients with TNFi who achieve clinical REM. A significant decrease in naive B-cell percentage is associated with achieving REM after 6 months of TNFi treatment in patients who received concomitant therapy with MTX.

Small molecule inhibitor of OGG1 blocks oxidative DNA damage repair at telomeres and potentiates methotrexate anticancer effects

The most common oxidative DNA lesion is 8-oxoguanine which is mainly recognized and excised by the 8-oxoG DNA glycosylase 1 (OGG1), initiating the base excision repair (BER) pathway. Telomeres are particularly sensitive to oxidative stress (OS) which disrupts telomere homeostasis triggering genome instability. In the present study, we have investigated the effects of inactivating BER in OS conditions, by using a specific inhibitor of OGG1 (TH5487). We have found that in OS conditions, TH5487 blocks BER initiation at telomeres causing an accumulation of oxidized bases, that is correlated with telomere losses, micronuclei formation and mild proliferation defects. Moreover, the antimetabolite methotrexate synergizes with TH5487 through induction of intracellular reactive oxygen species (ROS) formation, which potentiates TH5487-mediated telomere and genome instability. Our findings demonstrate that OGG1 is required to protect telomeres from OS and present OGG1 inhibitors as a tool to induce oxidative DNA damage at telomeres, with the potential for developing new combination therapies for cancer treatment.

The effects of drug transporters on the efficacy of methotrexate in the treatment of rheumatoid arthritis

The ATP-binding cassette (ABC) and solute carrier (SLC) transporter families consist of common drug transporters that mediate the efflux and uptake of drugs, respectively, and play an important role in the absorption, distribution, metabolism and excretion of drugs in vivo. Rheumatoid arthritis (RA) is an autoimmune disease characterized by erosive arthritis, and there are many RA patients worldwide. Methotrexate (MTX), the first-choice treatment for RA, can reduce the level of inflammation, prevent joint erosion and functional damage, and greatly reduce pain in RA patients. However, many patients show resistance to MTX, greatly affecting the efficacy of MTX. Many factors, such as irrational drug use and heredity, are associated with drug resistance. Considering the effect of drug transporters on drugs, many studies have compared the expression of drug transporters in drug-resistant and drug-sensitive patients, and abnormal transporter expression and transport activity have been found in patients with MTX resistance. Thus, drug transporters are involved in drug resistance. This article reviews the effects of transporters on the efficacy of MTX in the treatment of RA.

[Biologicals and small molecules for rheumatoid arthritis]

In recent years tremendous progress has been made in the therapeutic management of rheumatoid arthritis. Rheumatologists now have a large armamentarium of highly efficient drugs with different mechanisms of action at their disposal. These new drugs consist of biologicals (biological disease-modifying antirheumatic drugs, bDMARDs) as well as targeted synthetic DMARDs (tsDMARD). A common feature of these new drugs for treatment of rheumatoid arthritis is that the molecular target of the drug is known, which is not the case for conventional DMARDs. With the help of the new drugs, the therapeutic goal of inducing remission in patients with rheumatoid arthritis has become reality for many patients. Nevertheless, there is still a significant proportion of patients who do not adequately respond to all available drugs, leaving room for still further improvement. This review gives a short overview on the currently available and effective substances for the treatment of rheumatoid arthritis.

The many facets of macrophages in rheumatoid arthritis

Macrophages are central to the pathophysiology of rheumatoid arthritis (RA). They constitute the main source of pro-inflammatory cytokines and chemokines such as TNF and IL-1β, they activate a wide range of immune and non-immune cells, and they secrete diverse tissue degrading enzymes driving chronic pro-inflammatory, tissue destructive and pain responses in RA. However, they can also produce anti-inflammatory cytokines such as IL-10, secrete inhibitors of tissue degrading enzymes and promote immunoregulatory and protective responses, suggesting the existence of macrophages with distinct and diverse functional activities. Although the underlying basis of this phenomenon has remained obscure for years, emerging evidence has now provided insight into the mechanisms and molecular processes involved. Here, we review current knowledge on the biology of macrophages in RA, and highlight recent literature on the heterogeneity, origins and ontogeny of macrophages as part of the mononuclear phagocyte system. We also discuss their plasticity in the context of the M1/M2 paradigm, and the emerging theme of metabolic rewiring as a major mechanism for programming macrophage functions and pro-inflammatory activities. This sheds light into the many facets of macrophages in RA, their molecular regulation and their translational potential for developing novel protective and therapeutic strategies in the clinic.

Recapture and improved outcome of pegloticase response with methotrexate-A report of two cases and review of the literature

INTRODUCTION

Pegloticase is a PEGylated uric acid specific enzyme indicated for the treatment of refractory gout. Anti-pegloticase antibodies contribute to high discontinuation rates, increased risk of infusion reactions, and early loss of drug efficacy.

OBJECTIVE

To describe the use of methotrexate to recapture function of pegloticase after development of anti-drug antibodies while treating gout.

METHODS

We report two cases of using methotrexate as an adjunct to treatment with pegloticase for refractory tophaceous gout. We also present the results of a literature review on the use of concomitant immunosuppressive therapy with pegloticase to prevent anti-pegloticase antibody development.

RESULTS

Patient A, a 55-year-old man with a history of tophaceous gout, was treated with pegloticase but developed high serum urate(sUA) levels prior to his third infusion. Adjunctive treatment with methotrexate restored pegloticase response and the patient's sUA levels decreased, and remained low for the remainder of his treatment. Patient B, a 36-year-old man with a history of tophaceous gout, was treated with pegloticase. Oral methotrexate was initiated at the first infusion. Low sUA levels were achieved but increased after a lapse in methotrexate compliance. Re-initiation of methotrexate restored pegloticase response and the patient tolerated subsequent infusions. Literature review identified three reports of successful use of concomitant pegloticase and immunosuppressive therapy for refractory tophaceous gout, including an open label trial with a subset of 7 transplant recipients, an additional case study of pegloticase treatment with one transplant recipient, and a case study of pegloticase administered with low-dose azathioprine.

CONCLUSION

Prophylactic use of immunosuppressive therapy with pegloticase may enable sustained treatment and improve outcomes. Additionally, immunosuppressive therapy seems to show the ability to recapture pegloticase response after development of anti-drug antibodies. The use of immunosuppressants to prevent anti-drug antibody formation, recapture pegloticase efficacy, and reduce discontinuation rates warrants further study.

Pharmacokinetics and Exposure Response Relationships of Ustekinumab in Patients With Crohn's Disease

BACKGROUND & AIMS

Ustekinumab is a monoclonal antibody that binds with high affinity to the p40 subunit of human interleukin 12 (IL12 and IL23) that has been approved for treatment of patients with moderate to severe Crohn's disease (CD). However, there are few data on its pharmacokinetic properties or the relationship between drug exposure levels and patient response. We collected data from 2 Phase 3 induction studies and 1 maintenance study to determine ustekinumab's pharmacokinetic features, relationship between exposure and response, and optimal serum concentrations for efficacy.

METHODS

We collected data on serum concentrations of ustekinumab and efficacy from induction studies of patients with moderate to severe CD given ustekinumab for 8 weeks following a single intravenous dose (either 130 mg or approximately 6 mg/kg). We collected the same data from a maintenance study of patients with a response to ustekinumab in the induction study who then received subcutaneous injections (90 mg) every 8 or 12 weeks for 44 weeks. At week 44 of the maintenance study (52 weeks after treatment began), patients were evaluated for the primary endpoint of clinical remission (defined as a CD activity index score below 150 points), endoscopic markers of efficacy, and serum level of C-reactive protein. Ustekinumab concentration data were categorized into quartiles and relationships between exposure and response were assessed. Optimal concentration cutoff values were evaluated using receiver operating characteristic curve analysis.

RESULTS

Serum concentrations of ustekinumab over time were proportional to dose and did not differ significantly between the induction studies. In the maintenance study, ustekinumab concentration reached the steady state by the second maintenance dose; the median trough concentration was approximately threefold higher in patients given ustekinumab at 8-week intervals compared with 12-week intervals. Ustekinumab serum concentrations associated with rates of clinical remission and endoscopic efficacy endpoints, correlated inversely with level of C-reactive protein, and did not associate with use of immunomodulators. Trough concentrations of ustekinumab of 0.8 (or even up to 1.4 μg/mL) or greater were associated with maintenance of clinical remission in a higher proportion of patients than patients with lower trough concentrations.

CONCLUSIONS

In an analysis of data from Phase 3 studies of patients with moderate to severe CD, we found serum concentrations of ustekinumab to be proportional to dose and associate with treatment efficacy. Concentrations of ustekinumab did not seem to be affected by cotreatment with immunomodulators. Clinicaltrials.gov no. NCT01369329 (UNITI 1), NCT01369342 (UNITI 2), and NCT01369355 (IM-UNITI).

Median time to low disease activity is shorter in tocilizumab combination therapy with csDMARDs as compared to tocilizumab monotherapy in patients with active rheumatoid arthritis and inadequate responses to csDMARDs and/or TNF inhibitors: sub-analysis of the Swiss and Austrian patients from the ACT-SURE study

To analyse efficacy and safety of tocilizumab in patients with rheumatoid arthritis (RA) and an inadequate response to conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) and/or tumour necrosis factor (TNF) inhibitors of the Swiss and Austrian patients from the ACT-SURE study. This is a sub-analysis of RA patients from Switzerland and Austria, who participated in the international phase 3b, open-label, ACT-SURE study. Patients with an inadequate response to csDMARDs or TNF antagonists receiving 8 mg/kg of IV tocilizumab every 4 weeks during a 24-week time period were included into the study. Therapy with one or more csDMARDs could be continued as combination therapy with tocilizumab (Combo) or stopped, resulting in tocilizumab monotherapy (Mono), at the treating physician's discretion. These two patient groups were analysed in separate and compared. Overall, 107 (22 on Mono vs. 85 on Combo) patients were treated with tocilizumab. The percentage of patients with at least one adverse event was significantly lower in the tocilizumab combination (58.8%) as compared to the monotherapy group (81.8%, p = 0.0458). No differences in ACR20/50/70/90 response rates were observed between both treatment groups at week 24 (Mono 63.6, 40.9, 22.7, and 18.2% vs. Combo 61.2, 43.5, 25.9, and 10.6%). The median time to low disease activity (LDA) was significantly shorter in patients treated with tocilizumab combination therapy (Mono 9.1, Combo 7.9 weeks, log rank p = 0.038). In this post hoc regional sub-analysis of the ACT-SURE study, no differences for disease activity were found comparing the two patient groups at week 24. However, median time to LDA was statistically shorter in patients treated with tocilizumab combination therapy as compared to tocilizumab monotherapy. Consequently, adding tocilizumab to csDMARD therapy rather than changing to tocilizumab monotherapy may be, in our opinion, the safest strategy to reach maximum effect in RA patients with active disease despite treatment with csDMARD. csDMARDs can be withdrawn either immediately due to adverse events or after at least low disease activity has been reached.