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

The impact of autoantibodies on the efficacy of biological disease-modifying anti-rheumatic drugs in rheumatoid arthritis: meta-analysis of randomized controlled trials

OBJECTIVE

To investigate the efficacy of bDMARDs in patients with RA with RF/ACPA compared with patients without these autoantibodies.

METHODS

Previous systematic literature reviews performed by EULAR RA management task forces were searched for qualifying RCTs. RCTs investigating the efficacy of bDMARDs and including both autoantibody-positive (≤80% of total population) and -negative RA patients were eligible. For trials comparing bDMARD+csDMARD vs csDMARD, relative risks (RR) comparing two groups (RF+ vs RF-, ACPA+ vs ACPA-) were calculated for efficacy outcomes for each arm. Subsequently, relative risk ratios (RRRs) were computed, as the ratio of RR of the bDMARD-arm and the RR from the non-bDMARD-arm. Pooled effects were obtained with random effect meta-analyses.

RESULTS

Data from 28 eligible RCTs were analysed, pooling 23 studies in three subgroups: six including csDMARD-naive patients, 14 csDMARD-IR and three TNFi-IR patients. In csDMARD-naive and csDMARD-IR patients, seropositivity was not associated with a better response to bDMARDs: pooled 6-month ACR20 RRRs 1.02 (0.88-1.18) and 1.09 (0.90-1.32), respectively. Other outcomes showed no difference between groups either. In TNFi-IR patients, based on three trials, the 6-month ACR20 RRR was 2.28 (1.31-3.95), favoring efficacy in seropositive patients. Other outcomes mostly showed no significant difference between the groups. Based on the mode of action, efficacy was comparable between RF-positive and RF-negative patients for both TNFi and non-TNFi treatment and also for the individual bDMARDs.

CONCLUSION

The effect of bDMARDs is generally comparable in patients with and without RF/ACPA, regardless of the patient population, the mechanism of action or individual drug used.

Real-world clinical outcomes and rationale for initiating abatacept as a first-line biologic for patients with anticitrullinated protein antibody- and rheumatoid factor-positive rheumatoid arthritis

Aim: In rheumatoid arthritis (RA), seropositivity for both anticitrullinated protein antibody (ACPA) and rheumatoid factor (RF) is associated with disease severity and therapeutic response. Biologic (b) disease-modifying antirheumatic drugs (DMARDs) such as abatacept are recommended after inadequate response or contraindication to conventional synthetic DMARDs. This retrospective cohort study aimed to describe changes in Clinical Disease Activity Index (CDAI) measures over 12 months among patients with ACPA+ and RF+ RA with an inadequate response to methotrexate treated with abatacept as a first-line bDMARD. Patients & methods: Patient data were abstracted from medical records by treating rheumatologists. Analyses included McNemar tests for paired proportions or paired t-tests to assess longitudinal changes in CDAI scores, and Kaplan-Meier methods for time-to-event outcomes. Serious AEs and rationale for initiating treatment were recorded. Results: Overall, 296 patients were included. Mean CDAI scores improved (decreased) by 34.0, 61.0 and 74.0% (all p < 0.001) from baseline to 3-6 months, 6-12 months and ≥12 months after abatacept initiation, respectively. Of 279 patients not in CDAI low disease activity (LDA) or remission at baseline, 24.7% of patients achieved it within 6 months, 56.3% within 12 months and 71.0% at any point during follow-up after abatacept initiation. Median time to CDAI LDA/remission was 10.2 months. Serious AEs were reported in 2.4% of patients. Common reasons reported by rheumatologists for initiating abatacept were effectiveness/efficacy (52.7%), safety (31.4%) and patient preference (25.3%). Conclusion: In this analysis of patients with ACPA+ and RF+ RA treated with abatacept as a first-line bDMARD in a clinical practice setting, clinical outcomes and remission rates were improved at all time points, providing real-world evidence to further support the use of abatacept in this patient population.

Clinical presentation and treatment response in ACPA-negative rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation and potential extra-articular manifestations. This review compares the presentation and treatment response between anti-citrullinated protein antibodies (ACPA)-positive and ACPA-negative RA patients. The incidence of seronegative RA (rheumatoid factor [RF]-negative and ACPA-negative) has increased in recent decades, emphasizing the need for new diagnostic biomarkers. Diagnostically, ACPA is highly specific for RA, yet many patients remain ACPA-negative. The absence of RF and ACPA in RA should trigger further analysis to test alternative diagnosis, in particular when new symptoms arise. Emerging biomarkers like anti-PAD4 and anti-CarP antibodies provide additional diagnostic value, identifying some ACPA-negative patients. Clinically, ACPA-negative patients often exhibit higher disease activity at diagnosis, with more swollen joints and elevated CRP levels. They also tend to have fewer pulmonary and ocular manifestations compared to ACPA-positive patients. Radiographically, ACPA-positive patients are at a higher risk for joint erosions over time. Response to treatment also differs according to ACPA status. Abatacept and rituximab have demonstrated greater efficacy in ACPA-positive patients, showing better disease activity control and higher treatment retention rates. Continuous re-evaluation is crucial for ACPA-negative patients, especially when first-line treatments like methotrexate are ineffective, to rule out RA mimickers and adjust the treatment approach accordingly. These findings underscore the importance of personalized treatment strategies in RA management.

Preferable effect of CTLA4-Ig on both bone erosion and bone microarchitecture in rheumatoid arthritis revealed by HR-pQCT

This exploratory study aimed to examine the impact of abatacept treatment on bone structure in patients with rheumatoid arthritis (RA) using high-resolution peripheral quantitative computed tomography (HR-pQCT). RA patients initiating either abatacept or newly introduced csDMARDs were enrolled in this prospective, non-randomized, two-group study. Bone structure in the 2nd and 3rd metacarpal heads was assessed using HR-pQCT at 0, 6, and 12 months after enrollment. Synovitis was evaluated using musculoskeletal ultrasound and MRI. The adjusted mean between-group differences (abatacept-csDMARDs group) were estimated using a mixed-effect model. Thirty-five patients (abatacept group: n = 15; csDMARDs group: n = 20) were analyzed. Changes in erosion volume, depth and width were numerically smaller in the abatacept group compared to the csDMARDs group (adjusted mean between-group differences: - 1.86 mm3, - 0.02 mm, and - 0.09 mm, respectively). Over a 12-month period, 5 erosions emerged in the csDMARDs group, while only 1 erosion appeared in the abatacept group. Compared to csDMARDs, abatacept better preserved bone microarchitecture; several components of bone microarchitecture were significantly worsened at 6 months in the csDMARDs group, but were not deteriorated at 6 months in the abatacept group. Changes in synovitis scores were similar between the two treatment groups. Our results indicate that abatacept prevented the progression of bone erosion including new occurrence, and also prevented worsening of bone strength independently with synovitis compared to csDMARDs including MTX. Thus, abatacept treatment may provide benefits not only in inhibiting the progress of bone erosion but also in preventing bone microarchitectural deterioration.

Unlocking the Future: New Biologic Therapies for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that leads to joint destruction and functional disability. Traditional treatments, including disease-modifying antirheumatic drugs (DMARDs), often fail, leaving many patients without remission. The advent of biologic therapies that target specific immune system components (e.g., cytokines, T cells) has transformed RA treatment by offering new management options. These biologics (e.g., TNF inhibitors, interleukin blockers) are highly effective in controlling disease activity and preventing joint destruction. However, their use comes with safety concerns, particularly regarding immunosuppression and infection risks. Although still experimental, studies predict that future research will focus on enhancing the clinical response and safety of these agents through personalized approaches or novel mechanisms of action.

Biologics or Janus Kinase Inhibitors in Rheumatoid Arthritis Patients Who are Insufficient Responders to Conventional Anti-Rheumatic Drugs

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease which can induce progressive disability if not properly treated early. Over the last 20 years, the improvement of knowledge on the pathogenesis of the disease has made available several drugs targeting key elements of the pathogenetic process, which now represent the preferred treatment option after the failure of first-line therapy with conventional drugs such as methotrexate (MTX). To this category of targeted drugs belong anti-cytokine or cell-targeted biological agents and more recently also Janus kinase inhibitors (JAKis). In the absence to date of specific biomarkers to guide the therapeutic choice in the context of true precision medicine, the choice of the first targeted drug after MTX failure is guided by treatment cost (especially after the marketing of biosimilar products) and by the clinical characteristics of the patient (age, sex, comorbidities and compliance) and the disease (presence or absence of autoantibodies and systemic or extra-articular manifestations), which may influence the efficacy and safety profile of the available products. This viewpoint focuses on the decision-making process underlying the personalized approach to RA therapy and will analyse the evidence in the literature supporting the choice of individual products and in particular the differential choice between biological drugs and JAKis.

Should complete B cell depletion be maintained in patients treated long-term with rituximab for rheumatoid arthritis?

OBJECTIVE

To determine whether persistent complete B cell (BC) depletion was associated with a better clinical response in rheumatoid arthritis (RA) patients long-term treated with rituximab (RTX).

METHODS

We conducted a retrospective study including RA patients admitted for a new infusion between 2019 and 2021. The primary endpoint was the comparison of the mean disease activity score based on 28 joints (DAS28)-CRP at each of the four last infusion visits between patients with persistent complete BC depletion (mean CD19 counts <18/µl at each of the last four visits) or without persistent complete BC depletion (mean CD19 counts of the last four visits ≥18/µl). Secondary endpoints included DAS28, pain/fatigue visual analogue scale, CRP, gammaglobulins and the frequency of self-reported RA flares.

RESULTS

Of the 126 patients in maintenance therapy with RTX [exposure period: 76 (5) months, 14 (7) infusions received], 43 (34%) had persistent complete BC depletion at each of the four last infusions. The mean DAS28-CRP calculated at each of the four last infusion visits did not significantly differ according to persistence or not of complete BC depletion. This result remained unchanged after adjusting for antibody status, number of previous therapies, number of RTX infusion and cumulative RTX dose. All secondary outcomes were also not significantly different between the two groups.

CONCLUSION

Maintaining complete BC depletion does not appear to be a therapeutic target to achieve in RA patients in long-term maintenance therapy with RTX. There is a limited benefit of monitoring CD19 in RA patients long-term treated with RTX and having achieved low disease activity/remission.

Nipocalimab, an anti-FcRn monoclonal antibody, in participants with moderate to severe active rheumatoid arthritis and inadequate response or intolerance to anti-TNF therapy: results from the phase 2a IRIS-RA study

OBJECTIVES

To investigate the efficacy, safety, pharmacokinetics and pharmacodynamics of nipocalimab in participants with moderate to severe active rheumatoid arthritis (RA) and inadequate response or intolerance to ≥1 antitumour necrosis factor agent.

METHODS

In this phase 2a study, participants with RA seropositive for anticitrullinated protein antibodies (ACPA) or rheumatoid factors were randomised 3:2 to nipocalimab (15 mg/kg intravenously every 2 weeks) or placebo from Weeks 0 to 10. Efficacy endpoints (primary endpoint: change from baseline in Disease Activity Score 28 using C reactive protein (DAS28-CRP) at Week 12) and patient-reported outcomes (PROs) were assessed through Week 12. Safety, pharmacokinetics and pharmacodynamics were assessed through Week 18.

RESULTS

53 participants were enrolled (nipocalimab/placebo, n=33/20). Although the primary endpoint did not reach statistical significance for nipocalimab versus placebo, a numerically higher change from baseline in DAS28-CRP at Week 12 was observed (least squares mean (95% CI): -1.03 (-1.66 to -0.40) vs -0.58 (-1.24 to 0.07)), with numerically higher improvements in all secondary efficacy outcomes and PROs. Serious adverse events were reported in three participants (burn infection, infusion-related reaction and deep vein thrombosis). Nipocalimab significantly and reversibly reduced serum immunoglobulin G, ACPA and circulating immune complex levels but not serum inflammatory markers, including CRP. ACPA reduction was associated with DAS28-CRP remission and 50% response rate in American College of Rheumatology (ACR) criteria; participants with a higher baseline ACPA had greater clinical improvement.

CONCLUSIONS

Despite not achieving statistical significance in the primary endpoint, nipocalimab showed consistent, numerical efficacy benefits in participants with moderate to severe active RA, with greater benefit observed for participants with a higher baseline ACPA.

TRIAL REGISTRATION NUMBER

NCT04991753.

Anti-citrullinated protein antibody profiles predict changes in disease activity in patients with rheumatoid arthritis initiating biologics

OBJECTIVES

To determine whether an expanded antigen-specific ACPA profile predicts changes in disease activity in patients with RA initiating biologics.

METHODS

The study included participants from a prospective, non-randomized, observational RA cohort. For this sub-study, treatment groups of interest included biologic-naïve initiating anti-TNF, biologic-exposed initiating non-TNF, and biologic-naïve initiating abatacept. ACPAs to 25 citrullinated peptides were measured using banked enrolment serum. Principal component analysis (PCA) was performed and associations of resulting principal component (PC) scores (in quartiles) and anti-CCP3 antibody (≤15, 16-250 or >250 U/ml) with EULAR (good/moderate/none) treatment response at 6 months were examined using adjusted ordinal regression models.

RESULTS

Participants (n = 1092) had a mean age of 57 (13) years and 79% were women. At 6 months, 68.5% achieved a moderate/good EULAR response. There were three PCs that cumulatively explained 70% of variation in ACPA values. In models including the three components and anti-CCP3 antibody category, only PC1 and PC2 were associated with treatment response. The highest quartile for PC1 (odds ratio [OR] 1.76; 95% CI: 1.22, 2.53) and for PC2 (OR 1.74; 95% CI: 1.23, 2.46) were associated with treatment response after multivariable adjustment. There was no evidence of interaction between PCs and treatment group in EULAR responses (P-value for interaction >0.1).

CONCLUSION

An expanded ACPA profile appears to be more strongly associated with biologic treatment response in RA than commercially available anti-CCP3 antibody levels. However, further enhancements to PCA will be needed to effectively prioritize between different biologics available for the treatment of RA.

Comparative effectiveness of abatacept versus TNF inhibitors in rheumatoid arthritis patients who are ACPA and shared epitope positive

BACKGROUND

The HLA-DRB1 shared epitope (SE) is a risk factor for the development of rheumatoid arthritis (RA) and the production of anti-citrullinated protein antibodies (ACPAs) in RA patients. Our objective was to examine the real-world effectiveness of abatacept versus tumor necrosis factor inhibitors (TNFi) in patients with RA who were SE and anti-cyclic citrullinated peptide antibody (anti-CCP3) positive.

METHODS

Abatacept or TNFi initiators who were SE + and anti-CCP3+ (> 20 U/mL) at or prior to treatment and had moderate or high CDAI score (> 10) at initiation were identified. The primary outcome was mean change in CDAI score over six months. Analyses were conducted in propensity score (PS)-trimmed and -matched populations overall and a biologic-experienced subgroup. Mixed-effects models were used.

RESULTS

In the overall PS-trimmed (abatacept, n = 170; TNFi, n = 157) and PS-matched cohorts (abatacept, n = 111; TNFi, n = 111), there were numerically greater improvements in mean change in CDAI between abatacept and TNFi but were not statistically significant. Similar trends were seen for biologic-experienced patients, except that statistical significance was reached for mean change in CDAI in the PS-trimmed cohort (abatacept, 12.22 [95% confidence interval (95%CI) 10.13 to 14.31]; TNFi, 9.28 [95%CI 7.08 to 11.48]; p = 0.045).

CONCLUSION

In this real world cohort, there were numerical improvements in efficacy outcomes with abatacept over TNFi in patients with RA who were SE + and ACPA+, similar to results from a clinical trial population The only statistically significant finding after adjusting for covariates was greater improvement in CDAI with abatacept versus TNFi in the bio-experienced PS-trimmed cohort..

Hexokinase inhibitor 2-deoxyglucose coordinates citrullination of vimentin and apoptosis of fibroblast-like synoviocytes by inhibiting HK2 /mTORC1-induced autophagy

High hexokinase 2 (HK2) expression is associated with aberrant activation of fibroblast-like synoviocytes (FLSs) in rheumatoid arthritis (RA). However, the mechanism by which this occurs has not been fully elucidated. To investigate the role of HK2 and its underlying mechanism, adjuvant arthritis (AA) rats were treated with the HK2 inhibitor, 2-deoxyglucose (2-DG). In conjunction with HK2 knockdown experiments in FLSs, we evaluated the effect of HK2 on the citrullination of vimentin (cVIM), autophagy and apoptosis-associated protein expression, including that of cVIM, LC3, p62, Beclin1, Bax, Bcl2, and caspase 3. We further investigated the interaction of HK2 with downstream mTORC1 signaling effectors. Correlation analysis revealed that 2-DG treatment and HK2 knockdown upregulated the expression levels of caspase3, Bax, and p62 and downregulated the expression levels of LC3, Bcl2, and Beclin1, as well as decreasing vimentin citrullination. Furthermore, interactions between HK2 and mTOR decreased, coinciding with mTORC1 pathway activation. These findings suggest that the regulation of apoptosis and cVIM by HK2/mTORC1-dependent autophagy involves the inhibition of aberrant FLSs activation in the rat model of arthritis.

Baseline serum levels of cross-linked carboxy-terminal telopeptide of type I collagen predict abatacept treatment response in methotrexate-naive, anticitrullinated protein antibody-positive patients with early rheumatoid arthritis

OBJECTIVE

To investigate correlations between biomarkers of bone remodelling and extracellular matrix turnover with baseline disease activity and treatment response in patients with early rheumatoid arthritis (RA).

METHODS

Assessing Very Early Rheumatoid arthritis Treatment-2 (AVERT-2; NCT02504268) included disease-modifying antirheumatic drug-naive, anti-citrullinated protein antibody (ACPA)-positive patients randomised to weekly subcutaneous abatacept+methotrexate (MTX) or abatacept placebo+MTX for 56 weeks. This post hoc exploratory subanalysis assessed the association between baseline disease activity and eight biomarkers (Spearman's correlation coefficient), and whether baseline biomarkers (continuous or categorical variables) could predict treatment response at weeks 24 and 52 (logistic regression).

RESULTS

Patient characteristics were similar between overall (n=752) and biomarker subgroup (n=535) populations and across treatments. At baseline, neoepitopes of matrix metalloproteinase-mediated degradation products of types III and IV collagen and of C reactive protein (CRP) showed the greatest correlations with disease activity; cross-linked carboxy-terminal telopeptide of type I collagen (CTX-I) showed weak correlation. Only CTX-I predicted treatment response; baseline CTX-I levels were significantly associated with achieving Simplified Disease Activity Index remission and Disease Activity Score in 28 joints (DAS28 (CRP)) <2.6 (weeks 24 and 52), and American College of Rheumatology 70 response (week 52), in patients treated with abatacept+MTX but not abatacept placebo+MTX. CTX-I predicted significant differential response between arms for DAS28 (CRP) <2.6 (week 24). Treatment differences were greater for abatacept+MTX in patients with medium/high versus low baseline CTX-I.

CONCLUSION

In MTX-naive, ACPA-positive patients with early RA, baseline CTX-I predicted treatment response to abatacept+MTX but not abatacept placebo+MTX.

ACPA-negative rheumatoid arthritis: From immune mechanisms to clinical translation

The presence of anti-citrullinated protein autoantibodies (ACPA) is a hallmark feature of rheumatoid arthritis (RA), which causes chronic joint destruction and systemic inflammation. Based on ACPA status, RA patients can be sub-grouped into two major subsets: ACPA-positive RA (ACPA⁺ RA) and ACPA-negative RA (ACPA^– RA). Accumulating evidence have suggested that ACPA⁺ RA and ACPA^– RA are two distinct disease entities with different underlying pathophysiology. In contrast to the well-characterized pathogenic mechanisms of ACPA⁺ RA, the etiology of ACPA^– RA remains largely unknown. In this review, we summarized current knowledge about the primary drivers of ACPA^– RA, particularly focusing on the serological, cellular, and molecular aspects of immune mechanisms. A better understanding of the immunopathogenesis in ACPA^– RA will help in designing more precisely targeting strategies, and paving the road to personalized treatment. In addition, identification of novel biomarkers in ACPA^– RA will substantially promote early treatment and improve the outcomes.

Real-World Treatment Patterns and Clinical Outcomes of Baricitinib in Rheumatoid Arthritis Patients in Spain: Results of a Multicenter, Observational Study in Routine Clinical Practice (The ORBIT-RA Study)

INTRODUCTION

Baricitinib is an oral Janus kinase (JAK)1/JAK2 inhibitor approved to treat rheumatoid arthritis (RA). This study aimed to investigate patients' characteristics, prescription patterns, effectiveness, and treatment persistence in patients receiving baricitinib in real-world practice in Spain.

METHODS

This retrospective longitudinal cohort study conducted in five rheumatology units included adults with RA initiating baricitinib (Sep-2017-May-19) with at least a 6-month-follow-up. Demographic/clinical characteristics, prescription patterns, and changes in disease activity and pain level were collected until treatment discontinuation/end of follow-up. Treatment persistence was estimated by Kaplan-Meier methods.

RESULTS

Data from 182 patients were included (mean (SD)): 83.5% women, 62.2 (12.3) years, body mass index 26.8 (5.1), disease duration 13.2 (10.8) years and Charlson Comorbidity Index score 2.4 (2.0). All patients had received at least one conventional synthetic disease-modifying anti-rheumatic drugs (csDMARD) before starting baricitinib and 78.0% at least one biologic disease-modifying anti-rheumatic drugs (bDMARD). Furthermore, 90.1% started with baricitinib 4 mg/day; 43.4% in monotherapy. One hundred and twelve (61.5%) of patients continued baricitinib at data collection time; mean persistence was 14.1 (0.5) months. Overall treatment persistence was 79.7/64.8/59.1% at 6/12/18 months. Seventy (38.5%) patients discontinued baricitinib during follow-up due to loss of efficacy (68.6%) or adverse events (18.6%). In those patients with available scores at the different observed cut-off points, remission or low disease activity was reported in 71.6 and 76.3% of patients at 6/12 months at any index: Disease Activity Score 28 joints using erythrocyte sedimentation rate (DAS28-ESR) (73.1 and 73.5%), Simplified Disease Activity Index (SDAI) (62.4 and 75.0%), and Clinical Disease Activity Index (CDAI) (66.7 and 78.1%). Good or moderate European League Against Rheumatism (EULAR)-response was noted in 80.0 and 78.2% of patients, respectively. Improvement from baseline in pain (Visual Analog Scale) was 2.5 cm and 3.0 cm at 6/12 months, respectively.

CONCLUSIONS

This Spanish cohort of patients treated with baricitinib had a long-standing and refractory disease. Nevertheless, high persistence and improvements in disease activity and pain were found at 6 and 12 months after treatment initiation, independently of the composite disease activity measure used, reinforcing the effectiveness of baricitinib in routine clinical practice.