Mechanisms underlying DMARD inefficacy in difficult-to-treat rheumatoid arthritis: a narrative review with systematic literature search

The temporal association between adverse drug reactions and antirheumatic drugs utilisation in Western Australia: a retrospective study from real-world data (1995-2015)

BACKGROUND/OBJECTIVES

Adverse drug reactions (ADRs) can result in morbidity, mortality, and higher healthcare costs. Given the limited information available on ADRs associated with antirheumatic medications, this study aims to analyse and compare ADR reporting for these drugs in the pharmacovigilance datasets of Western Australia (WA) and the United States (US).

METHODS

Therapeutic Goods Administration provided WA pharmacovigilance data of selected antirheumatic drugs to from 1995 to 2015. The proportional reporting ratio (PRR) for WA case reports was compared to corresponding USA pharmacovigilance data by assessing the disproportionality of each ADR. clinically significant or true ADRs were determined using the Evans 2001 criteria (n > 2, chi-square > 4, PRR > 2).

RESULTS

A total of 232 reports were found in WA, mostly on sixty-nine women aged 45 to 69. Methotrexate, leflunomide, azathioprine, sulfasalazine, and infliximab had the highest reported ADRs, related to gastrointestinal disorders. Patients who used biological agents in WA had 2.7 times the likelihood of reporting true ADRs compared to conventional antirheumatic drugs. The ADR rates in the two datasets were comparable over the study period.

CONCLUSIONS

The PRR values of ADRs were consistent between WA and US databases. Methotrexate and infliximab use were commonly associated with ADR reports in WA females, with incidence rates comparable to the US; while patients using biological agents were more likely to report true ADRs than those on conventional antirheumatic drugs in WA.

New Therapeutic Strategies for the Inflammatory Rheumatoid Arthritis Disease: Emphasizing Mesenchymal Stem Cells and Associated exo-miRNA or exo-lncRNA

The most prevalent inflammatory arthritis and a leading contributor to disability is rheumatoid arthritis (RA). Although it may not have arrived in Europe until the 17th century, it was present in early Native American communities several thousand years ago. Exosomes released by mesenchymal stem cells (MSCs) are highly immunomodulatory due to the origin of the cell. As a cell-free therapy, MSCs-exosomes are less toxic and elicit a weakened immune response than cell-based therapies. Exosomal noncoding RNAs (ncRNAs) are closely associated with a number of biological and functional facets of human health, especially microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Various exo-miRNAs and lncRNAs such as HAND2-AS1, miR-150-5p, miRNA-124a, and miR-320a lodged with MSC could be appropriate therapeutic ways for RA treatment. These MSC-derived exosomes affect RA disorders via different molecular pathways such as NFK-β, MAPK, and Wnt. The purpose of this review is to review the research that has been conducted since 2020 so far in the field of RA disease treatment with MSC-loaded exo-miRNAs and exo-lncRNAs.

Poly-Refractory Rheumatoid Arthritis: An Uncommon Subset of Difficult to Treat Disease With Distinct Inflammatory and Noninflammatory Phenotypes

OBJECTIVE

To investigate the prevalence of poly-refractory rheumatoid arthritis (RA) defined as failure of all biological (b)/targeted synthetic (ts)-disease-modifying drugs (DMARDs). To further investigate whether patients with persistent inflammatory refractory RA (PIRRA) and noninflammatory refractory RA (NIRRA), determined by objective ultrasound (US) synovitis, have distinct clinical phenotypes in both EULAR difficult-to-treat RA (D2T-RA) and poly-refractory RA groups.

METHODS

A cross-sectional study of 1,591 patients with RA on b/tsDMARDs that evaluated D2T-RA criteria and subclassified as poly-refractory if inefficacy/toxicity to at least one drug of all classes. PIRRA was defined if US synovitis in one or more swollen joint and NIRRA if absent. Univariate tests and multivariate logistic regression were conducted to investigate factors associated with poly-refractory, PIRRA, and NIRRA phenotypes.

RESULTS

122 of 1,591 were excluded due to missing data. 247 of 1,469 (16.8%) had D2T-RA and only 40 of 1,469 (2.7%) poly-refractory RA. This latter group had higher disease activity score 28 C-reactive protein (CRP) (median 5.4 vs 5.02, P < 0.05), CRP levels (median 13 vs 5 mg/l, P < 0.01), and smoking (ever) rates (20% vs 4%, P < 0.01) compared with other D2T patients. Smoking was associated with poly-refractory RA (odds ratio 5.067, 95% CI 1.774-14.472, P = 0.002). Of 107 patients with D2T-RA with recent US, 61 (57%) were PIRRA and 46 (43%), NIRRA. Patients with NIRRA had elevated body mass index (median 30 vs 26, P < 0.001) and higher fibromyalgia prevalence (15% vs 3%, P < 0.05), lower swollen joint count (median: 2 vs 5, P < 0.001), and lower CRP levels (5 vs 10, P < 0.01).

CONCLUSION

Only 2.7% of D2T-RA failed all classes of b/tsDMARDs. Among D2T-RA, less than 60% had objective signs of inflammation, representing a target for innovative strategies.

Cayratia albifolia C.L.Li exerts anti-rheumatoid arthritis effect by inhibiting macrophage activation and neutrophil extracellular traps (NETs)

BACKGROUND

Cayratia albifolia C.L.Li (CAC), commonly known as "Jiao-Mei-Gu" in China, has been extensively utilized by the Dong minority for several millennia to effectively alleviate symptoms associated with autoimmune diseases. CAC extract is believed to possess significant anti-inflammatory properties within the context of Dong medicine. However, an in-depth understanding of the specific pharmaceutical effects and underlying mechanisms through which CAC extract acts against rheumatoid arthritis (RA) has yet to be established.

METHODS

Twenty-four Sprague-Dawley rats were divided into four groups, with six rats in each group. To induce the collagen-induced arthritis (CIA) model, the rats underwent a process of double immunization with collagen and adjuvant. CAC extract (100 mg/kg) was orally administered to rats. The anti-RA effects were evaluated in CIA rats by arthritis score, hind paw volume and histopathology analysis. Pull-down assay was conducted to identify the potential targets of CAC extract from RAW264.7 macrophage lysates. Moreover, mechanism studies of CAC extract were performed by immunofluorescence assays, real-time PCR and Western blot.

RESULTS

CAC extract was found to obviously down-regulate hind paw volume of CIA rats, with diminished inflammation response and damage. 177 targets were identified from CAC extract by MS-based pull-down assay. Bioinformatics analysis found that these targets were mainly enriched in macrophage activation and neutrophils extracellular traps (NETs). Additionally, we reported that CAC extract owned significant anti-inflammatory activity by regulating PI3K-Akt-mTOR signal pathway, and inhibited NETosis in response to PMA.

CONCLUSIONS

We clarified that CAC extract significantly attenuated RA by inactivating macrophage and reducing NETosis via a multi-targets regulation.

Inflammation-Targeting Mesenchymal Stem Cells Combined with Photothermal Treatment Attenuate Severe Joint Inflammation

Current clinical therapeutic efficacy for the treatment of osteo- and rheumatoid-arthritis is obviously limited. Although mesenchymal stem cells (MSCs) are considered as a source of promising regenerative therapy, un-modified or genetically engineered MSCs injected in vivo restrict their clinical utility because of the low drug efficacy and unpredicted side effect, respectively. Herein, a strategy to enhance the migration efficacy of MSCs to inflamed joints via an inflammation-mediated education process is demonstrated. To reinforce the limited anti-inflammatory activity of MSCs, gold nanostar loaded with triamcinolone is conjugated to MSC. Furthermore, near-infrared laser-assisted photothermal therapy (PTT) induced by gold nanostar significantly elevates the anti-inflammatory efficacy of the developed drugs, even in advanced stage arthritis model. An immunological regulation mechanism study of PTT is first suggested in this study; the expression of the interleukin 22 receptor, implicated in the pathogenesis of arthritis, is downregulated in T lymphocytes by PTT, and Th17 differentiation from naïve CD4 T cell is inhibited. Collectively, inflammation-targeting MSCs conjugated with triamcinolone-loaded gold nanostar (Edu-MSCs-AuS-TA) promote the repolarization of macrophages and decrease neutrophil recruitment in joints. In addition, Edu-MSCs-AuS-TA significantly alleviate arthritis-associated pain, improve general locomotor activity, and more importantly, induce cartilage regeneration even for severe stages of arthritis model.

Filgotinib Demonstrates Efficacy in Rheumatoid Arthritis Independent of Smoking Status: Post Hoc Analysis of Phase 3 Trials and Claims-Based Analysis

OBJECTIVES

To assess cigarette smoking's effects on efficacy of the preferential Janus kinase (JAK) 1 inhibitor filgotinib and drug persistence in patients with rheumatoid arthritis (RA).

METHODS

Efficacy in non-smokers, former smokers, and current smokers from phase 3 filgotinib trials was analyzed, including patients with inadequate response (IR) to methotrexate (MTX) or biologic disease-modifying antirheumatic drugs (bDMARDs) or who were MTX-naïve. Proportions achieving Disease Activity Score in 28 joints with C-reactive protein (DAS28[CRP]) ≤ 3.2 were compared using logistic regression. Retrospective claims-based switching data were reviewed.

RESULTS

Week 12 (W12) DAS28(CRP) ≤ 3.2 was achieved by 50, 61, and 62% of MTX-IR non-smokers, former smokers, and current smokers taking filgotinib 200 mg (FIL200) + MTX vs. 23, 16, and 32% taking placebo + MTX (p < 0.001, < 0.001, and 0.001) and 50, 34, and 33% taking adalimumab + MTX (p = 0.97, 0.013, and 0.006 vs. FIL200 + MTX). W12 DAS28(CRP) ≤ 3.2 was achieved by 46, 48, and 32% of bDMARD-IR non-smokers, former smokers, and current smokers taking FIL200 + conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) vs. 16, 23, and 5% taking placebo + csDMARD (p < 0.001, 0.077, and 0.051); 57, 58, and 59% of respective MTX-naïve smoking groups achieved W12 DAS28(CRP) ≤ 3.2 with FIL200 + MTX vs. 28, 37, and 18% with MTX (p < 0.001, 0.026, and < 0.001). Claims data showed former/current smokers were likelier than non-smokers to switch from adalimumab to other biologics or JAK inhibitors.

CONCLUSIONS

Greater proportions of MTX-IR current/former smokers responded to FIL200 + MTX vs. adalimumab + MTX. In non-smoking MTX-IR, bDMARD-IR, and MTX-naïve patients with RA, FIL200 + MTX demonstrated increased response vs. controls. Current/former smokers were likelier to discontinue adalimumab vs. non-smokers in real-world clinical settings.

TRIAL REGISTRATION

NCT02889796, NCT02873936, NCT02886728.

A Review of Difficult-to-Treat Rheumatoid Arthritis: Definition, Clinical Presentation, and Management

PURPOSE OF REVIEW

A subset of patients with rheumatoid arthritis (RA) who fail multiple biologic therapies are deemed to have "difficult-to-treat" (D2T) RA. In 2021, a European Alliance of Associations for Rheumatology (EULAR) task force proposed a clinical definition of D2T RA. Here we review RA phenotypes and clinical assessment of RA, propose a different definition of D2T RA, discuss possible D2T RA risk factors, and summarize existing literature on the management of D2T RA.

RECENT FINDINGS

High disease activity at the time of diagnosis or prior to treatment with a biologic is associated with the development of D2T RA. Prolonged time from diagnosis to beginning treatment has been consistently associated with the development of D2T RA. Other clinical factors such as burden of disease, extraarticular disease, obesity, smoking, pain, fatigue, and psychological conditions have inconsistent associations with D2T RA according to current literature. D2T RA is a relatively new concept that represents an area of great need for research regarding the characterization of those with the disease as well as how best to treat the disease. With this gained knowledge, rheumatologists will be able to better identify patients at the time of diagnosis that are likely to develop D2T RA to help guide management.

Heterogeneity of treatment responses in rheumatoid arthritis using group based trajectory models: secondary analysis of clinical trial data

BACKGROUND

Traditionally rheumatoid arthritis (RA) trials classify patients as responders and non-responders; they ignore the potential range of treatment responses. Group Based Trajectory Models (GBTMs) provide a more refined approach. They identify patient subgroups with similar outcome trajectories. We used GBTMs to classify patients into subgroups of varying responses and explore factors associated with different responses to intensive treatment in a secondary analysis of intensive treatment in the TITRATE clinical trial.

METHODS

The TITRATE trial enrolled 335 patients with RA: 168 patients were randomised to receive intensive management, which comprised monthly assessments including measures of the disease activity score for 28 joints (DAS28), treatment escalation when patients were not responding sufficiently and psychosocial support; 163 of these patients completed the trial. We applied GBTMs to monthly DAS28 scores over one year to these patients who had received intensive management. The control group had standard care and were assessed every 6 months; they had too few DAS28 scores for applying GBTMs.

RESULTS

GBTMs identified three distinct trajectories in the patients receiving intensive management: good (n = 40), moderate (n = 76) and poor (n = 47) responders. Baseline body mass index (BMI), disability, fatigue and depression levels were significantly different between trajectory groups. Few (10%) good responders were obese, compared to 38% of moderate, and 43% of poor responders (P = 0.002). Few (8%) good responders had depression, compared to 14% moderate responders, and 38% poor responders (P < 0.001). The key difference in treatments was using high-cost biologics, used in only 5% of good responders but 30% of moderate and 51% of poor responders (P < 0.001). Most good responders had endpoint remissions and low disability, pain, and fatigue scores; few poor responders achieved any favourable outcomes.

CONCLUSION

GBTMs identified three trajectories of disease activity progression in patients receiving intensive management for moderately active RA. Baseline variables like obesity and depression predicted different treatment responses. Few good responders needed biologic drugs; they responded to conventional DMARDs alone. GBTMs have the potential to facilitate precision medicine enabling patient-oriented treatment strategies based on key characteristics.

REGISTRATION

TITRATE Trial ISRCTN 70160382.

Unveiling difficult-to-treat rheumatoid arthritis: long-term impact of biologic or targeted synthetic DMARDs from the KOBIO registry

BACKGROUND

While the availability of biological or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) has improved outcomes for rheumatoid arthritis (RA) patients, there remains a subset of individuals who fail to achieve low disease activity or remission despite multiple cycles of b/tsDMARDs. This state is referred to as 'difficult-to-treat (D2T)' RA.

METHODS

Data from the Korean College of Rheumatology Biologics registry were utilized to analyze patients with RA who were treated with b/tsDMARDs.

RESULTS

Among 2,321 RA patients with RA treated with b/tsDMARDs, 271 (11.7%) were diagnosed with D2T RA. Lower age (OR = 0.98, p < 0.001), longer disease duration (OR = 1.06, p < 0.001), lower patient global assessment (OR = 0.89, p = 0.045), higher SDAI (OR = 1.06, p = 0.014) and RAPID3 (OR = 1.06, p = 0.002), lower RF positivity (OR = 0.65, p = 0.04), and lower prior use of methotrexate (OR = 0.44, p = 0.008), sulfasalazine (OR = 0.59, p = 0.003), and leflunomide (OR = 0.67, p = 0.013) were associated with D2T RA. The drug survival rate of b/tsDMARDs did not differ between patients with D2T RA and non-D2T RA (p = 0.35). However, the drug survival of individual b/tsDMARD differed between patients with D2T RA and non-D2T RA after eight years. Patients with D2T RA withdrew from b/tsDMARDs due to inefficacy more frequently than those without D2T RA (p < 0.001).

CONCLUSIONS

D2T RA patients experienced higher disease activity despite maintaining b/tsDMARD therapy. Withdrawal rates due to inefficacy were higher in D2T RA. Effective therapeutic strategies are needed to improve disease control and treatment outcomes in this unique patient population.

Inappropriate treatment response to DMARDs: A pathway to difficult-to-treat rheumatoid arthritis

In recent years, difficult-to-treat rheumatoid arthritis (D2T RA) has attracted significant attention from rheumatologists due to its poor treatment response and the persistent symptoms or signs experienced by patients. The therapeutic demands of patients with D2T RA are not properly met due to unclear pathogenic causes and a lack of high-quality data for current treatment options, creating considerable management difficulties with this patient population. This review describes the clinical challenges associated with disease-modifying antirheumatic drugs (DMARDs) and explores contributing factors associated with inappropriate response to DMARDs that may lead to D2T RA and related immunological dysregulation. It is now understood that D2T RA is a highly heterogeneous pathological status that involves multiple factors. These factors include but are not limited to genetics, environment, immunogenicity, comorbidities, adverse drug reactions, inappropriate drug application, poor adherence, and socioeconomic status. Besides, these factors may manifest in the selection and utilization of specific DMARDs, either individually or in combination, thereby contributing to inadequate treatment response. Finding these variables may offer hints for enhancing DMARD therapy plans and bettering the condition of D2T RA patients.

Difficult-to-treat inflammatory bowel disease: results from an international consensus meeting

Many patients with inflammatory bowel disease (IBD) have persistent symptoms and disease activity despite the best available medical or surgical treatments. These patients are commonly referred to as having difficult-to-treat IBD and need additional therapeutic strategies. However, the absence of standard definitions has impeded clinical research efforts and comparisons of data. Under the guidance of the endpoints cluster of the International Organization for the Study of Inflammatory Bowel Disease, we held a consensus meeting to propose a common operative definition for difficult-to-treat IBD. 16 participants from 12 countries voted on 20 statements covering various elements of difficult-to-treat IBD, such as failure of medical and surgical treatments, disease phenotypes, and specific complaints from patients. "Agreement" was defined as at least 75% consensus. The group agreed that difficult-to-treat IBD is defined by the failure of biologics and advanced small molecules with at least two different mechanisms of action, or postoperative recurrence of Crohn's disease after two surgical resections in adults, or one in children. In addition, chronic antibiotic-refractory pouchitis, complex perianal disease, and comorbid psychosocial complications that impair disease management also qualified as difficult-to-treat IBD. Adoption of these criteria could serve to standardise reporting, guide enrolment in clinical trials, and help identify candidates for enhanced treatment strategies.

Poor Translatability of Biomedical Research Using Animals - A Narrative Review

The failure rate for the translation of drugs from animal testing to human treatments remains at over 92%, where it has been for the past few decades. The majority of these failures are due to unexpected toxicity - that is, safety issues revealed in human trials that were not apparent in animal tests - or lack of efficacy. However, the use of more innovative tools, such as organs-on-chips, in the preclinical pipeline for drug testing, has revealed that these tools are more able to predict unexpected safety events prior to clinical trials and so can be used for this, as well as for efficacy testing. Here, we review several disease areas, and consider how the use of animal models has failed to offer effective new treatments. We also make some suggestions as to how the more human-relevant new approach methodologies might be applied to address this.

Difficult-to-treat rheumatoid arthritis (D2T RA): clinical issues at early stages of disease

OBJECTIVES

Most studies on difficult-to-treat rheumatoid arthritis (D2T RA) have focused on established RA. Here, we analyse whether disease activity in the early stages of RA could influence progression to a D2T RA under real-life conditions. Other clinical and treatment-related factors were also analysed.

METHODS

A longitudinal multicentre study of patients with RA was conducted from 2009 to 2018. Patients were followed up until January 2021. D2T RA was defined based on EULAR criteria (treatment failure, signs suggestive of currently active/progressive disease and management being perceived as problematic by the rheumatologist and/or patient). The main variable was disease activity in the early stages. The covariates were sociodemographic, clinical and treatment-related factors. We ran a multivariable logistic regression analysis to investigate risk factors associated with progression to D2T RA.

RESULTS

The study population comprised 631 patients and 35 (5.87%) developed D2T RA. At the time of diagnosis, the D2T RA group were younger, with a higher disability, 28-joint Disease Activity Score (DAS28) score, tender joint count and pain scores. In our final model, DAS28 was not statistically significantly associated with D2T RA. No differences were found between groups for therapy. Disability was independently associated with D2T RA (OR: 1.89; p=0.01).

CONCLUSIONS

In this cohort of patients newly diagnosed with RA, our results do not allow us to prove the influence of active disease according to DAS28. However, we did find that younger patients and those with elevated initial disability scores are more likely to develop D2T RA regardless of other factors.

Difficult-to-treat rheumatoid arthritis: Current concept and unsolved problems

Over the past several decades, the treatment of rheumatoid arthritis (RA) has advanced significantly, and clinical, structural, and functional remission are achievable therapeutic goals. However, a substantial number of patients show resistance to multiple drugs. In particular, patients whose disease activity cannot be controlled despite the use of two or more biological disease-modifying antirheumatic drugs (DMARDs) or targeted synthetic DMARDs (tsDMARDs) with different mechanisms of action (MOA) have recently been referred to as having difficult-to-treat RA (D2T RA). D2T RA is a heterogeneous and multifactorial disease state, and the major problems are uncontrolled disease activity and decreased quality of life, as well as the economic burden due to frequent healthcare utilization and multiple admissions. Since the concept of D2T RA is relatively new and publication regarding D2T RA is limited, the mechanism underlying DMARD inefficacy and which factors form a "difficult-to-treat" state in such patients are not yet fully understood. It is also possible that factors contributing to D2T RA may differ by patient, sex, country, and race. The present Mini Review introduces the current concept and unsolved problems of D2T RA, including the definition, prevalence, and factors contributing to D2T RA. We then discuss the management and therapeutic strategies for D2T RA. Finally, we explore a clinical approach to prevent patients from developing D2T RA.

Clinical evidence construction of East Asian herbal medicine for inflammatory pain in rheumatoid arthritis based on integrative data mining approach

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disease that leads to a significant social burden. East Asian herbal medicine (EAHM) has long been used to treat RA. Therefore, a systematic study of how EAHM treatments can be developed into new drugs using specific materials is needed.

METHODS

Eleven databases containing literature in English, Korean, Chinese, and Japanese were searched for randomized controlled trials comparing EAHM with conventional medicine (CM). A meta-analysis was performed on the variable data to assess their effects on inflammatory pain. Subsequently, we searched for core materials and combinations of core material-based data mining methods.

RESULTS

A total of 186 trials involving 19,716 patients with RA met the inclusion criteria. According to the meta-analysis, EAHM had a significantly superior effect on continuous pain intensity, tender joint count, and response rate. Patients treated with EAHM had a significantly reduced incidence of adverse events compared with those treated with CM. Based on additional analysis of the EAHM formula data included in this meta-analysis, 21 core materials and five core herbal combinations were identified.

CONCLUSION

EAHM remedies for RA have the adequate potential for use as candidate materials for treating inflammatory pain in RA. The candidate core herbs evaluated in this study act on multiple pathways and are expected to provide pain relief, sustained inflammation suppression, immune regulation, and prevention of joint destruction. It seems worthwhile to conduct follow-up research on drug development using the core materials derived from this review.

Mitochondrial Dysfunction and Oxidative Stress in Rheumatoid Arthritis

Control of excessive mitochondrial oxidative stress could provide new targets for both preventive and therapeutic interventions in the treatment of chronic inflammation or any pathology that develops under an inflammatory scenario, such as rheumatoid arthritis (RA). Increasing evidence has demonstrated the role of mitochondrial alterations in autoimmune diseases mainly due to the interplay between metabolism and innate immunity, but also in the modulation of inflammatory response of resident cells, such as synoviocytes. Thus, mitochondrial dysfunction derived from several danger signals could activate tricarboxylic acid (TCA) disruption, thereby favoring a vicious cycle of oxidative/mitochondrial stress. Mitochondrial dysfunction can act through modulating innate immunity via redox-sensitive inflammatory pathways or direct activation of the inflammasome. Besides, mitochondria also have a central role in regulating cell death, which is deeply altered in RA. Additionally, multiple evidence suggests that pathological processes in RA can be shaped by epigenetic mechanisms and that in turn, mitochondria are involved in epigenetic regulation. Finally, we will discuss about the involvement of some dietary components in the onset and progression of RA.