Impact of anti-citrullinated protein antibody on tumor necrosis factor inhibitor or abatacept response in patients with rheumatoid arthritis

Comparative effectiveness of treatments for rheumatoid arthritis in clinical practice: A systematic review

OBJECTIVE

To assess real-world comparative effectiveness studies of biologic (b) and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARDs) in adults with rheumatoid arthritis (RA) through a systematic review.

METHODS

We searched Medline for journal articles (2001-2021) and Embase® for abstracts presented at the European Alliance of Associations for Rheumatology and American College of Rheumatology (ACR) 2020 and 2021 annual meetings on non-randomized studies comparing the effectiveness of b/tsDMARDs using ACR-recommended disease activity measures, measures of functional status, and patient-reported outcomes (HAQ, PROMIS PF, patient pain, Patient and Physician Global Assessment of disease activity). Methodological heterogeneity between studies precluded meta-analyses. Risk of bias was assessed using the Cochrane Risk Of Bias In Non-randomized Studies of Interventions-I tool.

RESULTS

Of 1283 records screened, 68 were selected for data extraction, of which 1 was excluded due to critical risk of bias. Most studies were multicenter observational cohort/registry studies (n = 60) and were published between 2011 and 2021 (n = 60). Mean or median reported RA duration was between 6 and 15 years. Disease Activity Score in 28 joints (46 studies), Clinical Disease Activity Index (37 studies), and Health Assessment Questionnaire-Disability Index (32 studies) were the most common outcomes used in clinical practice, with regional differences identified. The most common comparison was between tumor necrosis factor inhibitors (TNFis) and non-TNFi bDMARDs (35 studies). There were no evident differences between b/tsDMARDs in clinical effectiveness.

CONCLUSION

This systematic review summarizing real-world evidence from a very large number of global studies found there are many effective options for the treatment of RA, but relatively less evidence to support the use of any one b/tsDMARD or drug class over another. Treatment for patients with RA should be tailored to suit individual clinical profiles. Further research is needed to identify whether specific patient subgroups may benefit from specific drug classes.

Efficacy of Abatacept Versus Tumor Necrosis Factor Inhibitors in Anti-citrullinated Protein Antibody-Positive Patients with Rheumatoid Arthritis: Results from a Korean Nationwide Biologics Registry

INTRODUCTION

To compare the efficacy of abatacept and tumor necrosis factor inhibitor (TNFi) in patients with anti-citrullinated protein antibody (ACPA)-positive rheumatoid arthritis (RA) and identify those who benefit most from abatacept over TNFi.

METHODS

This observational study identified RA patients who were ACPA-positive and initiated abatacept or TNFi from the Korean College of Rheumatology Biologics and Targeted therapy registry. Propensity score (PS) matching was performed to balance baseline confounding in abatacept- or TNFi-treated patients. The major endpoints were changes in Clinical Disease Activity Index (CDAI) and achievement of CDAI remission/low disease activity after 1 year of treatment. Subgroup analysis was mainly performed stratified by prior biologics use.

RESULTS

A total of 291 PS-matched, ACPA-positive RA patients who initiated abatacept (n = 97) and TNFi (n = 194) were included. From baseline CDAI scores of 26.52 in the abatacept group and 26.38 in the TNFi group, the mean changes after 1 year were - 16.78 and - 13.61, respectively (difference - 3.17, p = 0.020). The proportion of patients achieving CDAI remission/low disease activity was 68.0% with abatacept and 52.6% with TNFi (p = 0.013). In the subgroup analysis, patients that were biologics-naïve had better improvement in CDAI after treatment with abatacept than TNFi (difference - 3.35, p = 0.021).

CONCLUSIONS

This real-world study suggests that abatacept may have better clinical response compared to TNFi in patients with established ACPA-positive RA, especially in those that were biologics-naïve.

Baseline Anti-Citrullinated Protein Antibody Status and Response to Abatacept or Non-TNFi Biologic/Targeted-Synthetic DMARDs: US Observational Study of Patients with RA

INTRODUCTION

Patients with rheumatoid arthritis (RA) may respond to treatments differently based on their underlying serology and biomarker status, but real-world data comparing treatment responses to abatacept versus other non-TNFi biologic or targeted-synthetic DMARDs by anti-citrullinated protein antibody (ACPA) status remain limited. We assessed the association between ACPA status and response to treatment in patients with RA.

METHODS

Adults from CorEvitas' RA Registry were identified who initiated abatacept, rituximab, tocilizumab, or tofacitinib, and had ACPA measured at/prior to treatment initiation and at the 6-month follow-up visit. Three cohorts were included: abatacept/rituximab (2006-2019), abatacept/tocilizumab (2010-2019), and abatacept/tofacitinib (2012-2019). Patient characteristics at initiation were compared by ACPA status (positive [+], anti-cyclic citrullinated peptide-2 [anti-CCP2] ≥ 20 U/ml; negative [-], anti-CCP2 < 20 U/ml). Outcomes over 6 months: changes in Clinical Disease Activity Index (CDAI), modified Health Assessment Questionnaire (mHAQ), patient global assessment (PGA) scores, and proportion of patients achieving a clinical response. Adjusted mean differences and odds ratios were estimated using mixed-effects linear regression models.

RESULTS

Overall, 982 abatacept, 246 rituximab, 404 tocilizumab, and 429 tofacitinib initiators were identified. ACPA+ (vs. ACPA-) patients had longer disease duration and more erosive disease. During most time periods adjusted mean changes in CDAI, mHAQ, and PGA scores and the proportion of patients achieving a clinical response were significantly higher for ACPA+ versus ACPA- patients initiating abatacept. Adjusted mean change in PGA score and patient fatigue were significantly higher for ACPA+ versus ACPA- patients initiating rituximab. No significant differences were seen by ACPA status for patients initiating tocilizumab or tofacitinib.

CONCLUSIONS

Patients who initiated abatacept or rituximab and were ACPA+ had a greater clinical response at 6-month follow-up post index compared to patients who were ACPA- treated with the same biologic.

Citrullination in the pathology of inflammatory and autoimmune disorders: recent advances and future perspectives

Numerous post-translational modifications (PTMs) govern the collective metabolism of a cell through altering the structure and functions of proteins. The action of the most prevalent PTMs, encompassing phosphorylation, methylation, acylations, ubiquitination and glycosylation is well documented. A less explored protein PTM, conversion of peptidylarginine to citrulline, is the subject of this review. The process of citrullination is catalysed by peptidylarginine deiminases (PADs), a family of conserved enzymes expressed in a variety of human tissues. Accumulating evidence suggest that citrullination plays a significant role in regulating cellular metabolism and gene expression by affecting a multitude of pathways and modulating the chromatin status. Here, we will discuss the biochemical nature of arginine citrullination, the enzymatic machinery behind it and also provide information on the pathological consequences of citrullination in the development of inflammatory diseases (rheumatoid arthritis, multiple sclerosis, psoriasis, systemic lupus erythematosus, periodontitis and COVID-19), cancer and thromboembolism. Finally, developments on inhibitors against protein citrullination and recent clinical trials providing a promising therapeutic approach to inflammatory disease by targeting citrullination are discussed.