Personalization of biologic therapy in patients with rheumatoid arthritis: less frequently accounted choice-driving variables

Risk of infection from glucocorticoid and methotrexate interaction in patients with rheumatoid arthritis using biologics: A retrospective cohort study

AIMS

This retrospective cohort study aimed to evaluate the effect of the interaction between methotrexate and glucocorticoids on the risk of developing bacterial infections in patients with rheumatoid arthritis (RA) using biological disease-modifying antirheumatic drugs (bDMARDs).

METHODS

We used the 2005-2018 JMDC claims database, a nationwide claims database in Japan. From the database of 7 175 048 patients, study patients were obtained by applying the following exclusion criteria: no use of bDMARDs; without information on the date of prescription; without RA as a disease; other than the new users of bDMARDs; and age <18 years. The exposures were glucocorticoids and methotrexate, and the outcome was bacterial infection. The interaction effects were examined using multivariate Cox regression analysis. Bacterial infections were identified according to antibiotic prescription and International Statistical Classification of Diseases and Related Health Problems, 10th revision codes.

RESULTS

A total of 2837 RA patients were identified, with a median age of 50 years. The incidence of infection was 16.8% (95% confidence interval: 15.5-18.3). The interaction term for the doses of glucocorticoids and methotrexate was significant. Additionally, a higher dose of glucocorticoid was a significant risk factor for developing bacterial infections on the side of high doses of methotrexate. The incidence of bacterial infections tended to increase significantly with increasing methotrexate doses coprescribed with glucocorticoids ≥5 mg or glucocorticoid doses coprescribed with methotrexate ≥8 mg.

CONCLUSION

Our results indicate a potential association between methotrexate dose and bacterial infections during bDMARDs administration with glucocorticoids in patients with RA.

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

Management of RA patients has significantly improved over the past decades. However, a substantial proportion of patients is difficult-to-treat (D2T), remaining symptomatic after failing biological and/or targeted synthetic DMARDs. Multiple factors can contribute to D2T RA, including treatment non-adherence, comorbidities and co-existing mimicking diseases (e.g. fibromyalgia). Additionally, currently available biological and/or targeted synthetic DMARDs may be truly ineffective ('true' refractory RA) and/or lead to unacceptable side effects. In this narrative review based on a systematic literature search, an overview of underlying (immune) mechanisms is presented. Potential scenarios are discussed including the influence of different levels of gene expression and clinical characteristics. Although the exact underlying mechanisms remain largely unknown, the heterogeneity between individual patients supports the assumption that D2T RA is a syndrome involving different pathogenic mechanisms.

Impact of immunogenicity on clinical efficacy and toxicity profile of biologic agents used for treatment of inflammatory arthritis in children compared to adults

The treatment of inflammatory arthritis has been revolutionised by the introduction of biologic treatments. Many biologic agents are currently licensed for use in both paediatric and adult patients with inflammatory arthritis and contribute to improved disease outcomes compared with the pre-biologic era. However, immunogenicity to biologic agents, characterised by an immune reaction leading to the production of anti-drug antibodies (ADAs), can negatively impact the therapeutic efficacy of biologic drugs and induce side effects to treatment. This review explores for the first time the impact of immunogenicity against all licensed biologic treatments currently used in inflammatory arthritis across age, and will examine any significant differences between ADA prevalence, titres and timing of development, as well as ADA impact on therapeutic drug levels, clinical efficacy and side effects between paediatric and adult patients. In addition, we will investigate factors associated with differences in immunogenicity across biologic agents used in inflammatory arthritis, and their potential therapeutic implications.

Exposure-Response Relationship of Certolizumab Pegol and Achievement of Low Disease Activity and Remission in Patients With Rheumatoid Arthritis

Anti-tumor necrosis factor (anti-TNF) drugs are often prescribed for the treatment of rheumatoid arthritis (RA) and other immune-mediated inflammatory diseases. Although this treatment has been shown to be effective in many patients, up to 40% of patients do not achieve disease control. Drug concentration in plasma may be a factor affecting the observed variability in therapeutic response. In this study, we aimed to identify the plasma concentrations of the anti-TNF certolizumab pegol (CZP), associated with improvement in disease activity in patients with RA. Data were pooled from three randomized, controlled clinical trials with a combined total of 1,935 patients analyzed. Clinical outcomes of low disease activity (LDA) and remission were defined as Disease Activity Score in 28 joints with C-reactive protein (DAS28(CRP)) ≤ 2.7 and < 2.3, respectively. Quartile analysis results indicated that there may be an exposure-response relationship between CZP concentration and LDA/remission outcomes at weeks 12 and 24; the association was strongest for LDA (P < 0.05). Receiver operating characteristic (ROC) analysis showed that CZP concentrations ≥ 28.0 μg/ml at week 12, and ≥ 17.6 μg/ml at week 24, were associated with a greater likelihood of achieving LDA/remission outcomes. Although confirmatory studies are warranted to define the optimal CZP therapeutic range at weeks 12 and 24, these data indicate that CZP concentrations may be associated with improvement of disease activity.