Predictors for clinical effectiveness of baricitinib in rheumatoid arthritis patients in routine clinical practice: data from a Japanese multicenter registry

The Real-World Effectiveness, Persistence, Adherence, and Safety of Janus Kinase Inhibitor Baricitinib in Rheumatoid Arthritis: A Long-Term Study

Background/Aim: Baricitinib (BAR) is the first oral selective Janus kinase inhibitor approved in Europe for rheumatoid arthritis (RA). Real-world data are still needed to clarify its long-term benefits/risk profile. This study aimed to evaluate the effectiveness, persistence, adherence, and safety of BAR in a real-world setting. Methods: An ambispective study was conducted between October 2017 and December 2021 in RA patients starting BAR. The effectiveness was evaluated, assessing changes from the baseline of the Disease Activity Score using 28-joint counts-C reactive protein (DAS28CRP), and the achievement of low disease activity/remission. Drug persistence was evaluated using Kaplan-Meier analysis. Adherence was estimated using the medication possession ratio (MPR) and the 5-item Compliance Questionnaire for Rheumatology. Safety was assessed determining global incidence proportion and adverse event adjusted incidence rates. Results: In total, 61/64 recruited patients were finally analyzed, 83.6% were female, 78.7% were seropositive, the mean age was 58.1 (15.4) years, and the disease duration was 13.9 (8.3) years. A total of 32.8% of patients were naïve to biologics and 16.4% received BAR as monotherapy. The median exposure to BAR was 12.4 (6.6-31.2) months (range 3.1-51.4). A significant change in DAS28CRP was observed after treatment (difference -1.2, p = 0.000). 70.5% and 60.7% of patients achieved low disease activity or remission, respectively, and 50.8% (31/61) remained on BAR throughout the follow-up, with a median persistence of 31.2 (9.3-53.1) months. The average MPR was 0.96 (0.08) and all patients exhibited "good adherence" according to the questionnaire. In total, 21.3% of patients discontinued baricitinib due to toxicity. Conclusions: In our real-world practice, BAR demonstrated effectiveness, large persistence, high adherence to treatment, and an acceptable safety profile.

The steroid-sparing effect of JAK inhibitors across multiple patient populations

Introduction

JAK-inhibitors (JAK-i) represent an effective treatment in Rheumatoid Arthritis (RA) and Psoriatic Arthritis (PsA). Oral glucocorticoids (OGC) are commonly used in combination with JAK-i to reach therapeutic target. We aimed to assess, in a real-life setting, the reduction of OGC dose during JAK-i treatment in active RA and PsA patients.

Methods

We prospectively enrolled 103 patients (88 RA, 15 PsA) treated with JAK-i: 24% bio-naïve (b-naïve), 76% bDMARD-insufficient responders (bDMARD-IR) and 40% difficult to treat (D2T), defined as failure of ≥2 bDMARDs with different mechanism of action. Disease activity (DAS28 and DAPSA, VAS-pain, GH) and OGC dose was collected at baseline and after 3, 6 and 12 months (T3, T6, T12) of treatment.

Results

In all the cohort and in b-naïve patients we reported a reduction of OGC dose at all time-points; bDMARD-IR patients were able to reduce OGC dose at T3 and T12; D2T ones only at T3. We reported an improvement of disease activity and withdrawal of OGC as early as three months of therapy, at all time-points, regardless of line of bDMARD treatment.

Conclusion

Chronic OGC may cause detrimental bone, metabolic, cardiovascular side effects and infections; therefore JAK-i steroid-sparing effect may be beneficial for patients in long-term treatment.

2023 Management Recommendations of Bangladesh Rheumatology Society on Pharmacological Treatment of Rheumatoid Arthritis With Synthetic and Biologic Disease-Modifying Drugs

Rheumatoid arthritis (RA) is the most common inflammatory polyarthritis in Bangladesh. Bangladesh Rheumatology Society (BRS) proposes these management recommendations to treat the considerable burden of RA in the resource-constrained situation based on the best current evidence combined with societal challenges and opportunities. BRS formed a task force (TF) comprising four rheumatologists. The TF searched for all available literature, including updated American College of Rheumatology (ACR), European Alliance of Associations for Rheumatology (EULAR), and Asia-Pacific League of Associations for Rheumatology (APLAR) and several other guidelines, and systematic literature reviews until October 2023, and then a steering committee was formed, which included rheumatologists and internists. We followed the EULAR standard operating procedures to categorize levels of evidence and grading of recommendations. This recommendation has two parts -- general (diagnosis of RA, nomenclature of disease-modifying anti-rheumatic drugs [DMARDs], disease activity indices) and management portion. The TF agreed on four overarching principles and 12 recommendations. Overarching principles deal with early diagnosis and disease activity monitoring. Recommendations 1-5 discuss using glucocorticoids, NSAIDs, and conventional synthetic DMARDs (csDMARD). Recommendations 6-9 stretch the use of targeted synthetic DMARDs (tsDMARDs) and biological DMARDs (bDMARDs). The suggested DMARD therapy includes initiation with methotrexate (MTX) or another csDMARD (in case of contraindication to MTX) in the first phase and the addition of a tsDMARD in the second phase, switching to an alternative tsDMARDs or bDMARDs in the subsequent phases. The TF included the Padua prediction score for the thromboembolism risk estimation. Recommendations 10-12 cover infection screening, vaccination, and DMARD tapering. Bangladesh has a higher prevalence of RA. This recommendation will serve as a tool to treat this high burden of patients with RA scientifically and more effectively.

Post hoc analysis of patients with rheumatoid arthritis under clinical remission in two Japanese Phase 3 trials of peficitinib treatment (RAJ3 and RAJ4)

OBJECTIVE

We evaluated remission rates and their relationship with baseline characteristics in patients with rheumatoid arthritis treated with the oral Janus kinase inhibitor peficitinib.

METHODS

This post hoc analysis of data from two Phase 3 studies (RAJ3 and RAJ4) of peficitinib (100 and 150 mg/day) in Asian rheumatoid arthritis patients investigated clinical disease activity index (CDAI) remission and low disease activity rates from baseline to Week 52. CDAI, Health Assessment Questionnaire-Disability Index, and van der Heijde-modified total Sharp score remission/low disease activity rates at Week 52 were evaluated among patients achieving CDAI remission at Weeks 12/28. Logistic regression analyses explored the relationship between baseline characteristics and CDAI remission/low disease activity rates.

RESULTS

CDAI remission rates increased over time in a dose-dependent manner in both peficitinib-treated groups. Most patients achieving CDAI remission at Weeks 12/28 also achieved remission at Week 52. Following the multivariate analysis of demographic and baseline characteristics, factors associated with the achievement of CDAI remission at Week 28 included male sex, low baseline prednisone dose (RAJ3 only), and low baseline Disease Activity Score 28-C-reactive protein (RAJ4 only).

CONCLUSIONS

Peficitinib demonstrated persistent efficacy in clinical remission to Week 52. Baseline characteristics associated with CDAI remission were mostly consistent with previous studies using other disease-modifying antirheumatic drugs.

Safety and effectiveness of peficitinib 100 mg/day in patients achieving clinical remission from a long-term open-label extension study in Japan, Korea, and Taiwan (RAJ2)

OBJECTIVES

This post hoc analysis of the RAJ2 study assessed long-term safety and effectiveness of peficitinib 100 mg/day for treatment of rheumatoid arthritis.

METHODS

Eligible patients previously completed two Phase 3 (RAJ3 and RAJ4) studies of peficitinib in Asia. All patients received peficitinib 100 mg/day at RAJ2 Week (W)0; dose change to 50 mg/day or 150 mg/day was permitted. Safety endpoints included treatment-emergent adverse events and laboratory test results. Effectiveness endpoints included peficitinib exposure pattern, achievement of Clinical Disease Activity Index (CDAI) remission by peficitinib exposure pattern at W0 and W48, and association of demographics/characteristics with CDAI remission at W0 and W48.

RESULTS

Overall, no new safety findings were reported at W48, and renal function was unaffected. Of patients included in effectiveness analyses at W48, 70.9% (451/636) had maintained peficitinib 100 mg/day since W0. Of patients who achieved CDAI remission at W0 and maintained peficitinib 100 mg/day to W48, 50.3% (79/157) maintained CDAI remission to W48. Low disease activity and a lower number of prior disease-modifying antirheumatic drugs were significantly associated with CDAI remission at W48.

CONCLUSIONS

Long-term peficitinib treatment at a dose of 100 mg/day was generally well tolerated and, following induction therapy, maintained effectiveness through to W48.

Characteristics of patients initiating treatment with baricitinib and outcomes at follow-up: analysis of BSRBR-RA Registry data

OBJECTIVES

To describe selected baseline characteristics, continuation with baricitinib and disease activity over time in patients initiating treatment with baricitinib in a UK real-world rheumatology setting.

METHODS

Baseline and follow-up data were analysed from baricitinib-treated patients newly recruited to the British Society for Rheumatology Biologics Registry-RA (BSRBR-RA) baricitinib cohort between 1 January 2018 and 31 March 2020. The primary objective was to evaluate continuation of baricitinib treatment in patients with at least one follow-up. Analyses were performed using the full baricitinib cohort, overall and by patient subgroup: biologic DMARD (bDMARD)/targeted synthetic (ts)DMARD-naive vs -experienced, baricitinib 4 vs 2 mg, age ≥65 vs <65 years, monotherapy vs combination therapy and male vs female.

RESULTS

At baseline, the study cohort (n = 561) was 76.5% female, mean age 60.0 years, had longstanding (mean 13.1 years) and severe RA, and 54.0% had previously received a bDMARD/tsDMARD. Of 265 and 110 patients completing the 6- and 12-month follow-ups with available data, 77.7 and 69.1% remained on baricitinib at each time, respectively. In all Kaplan-Meier analyses, >60% of patients remained on baricitinib at 540 days. Continuation of baricitinib therapy differed between some subgroup pairs (bDMARD/tsDMARD naive/experienced, baricitinib 2 mg/4 mg). Disease activity was lower at both follow-ups than at baseline, overall and in all subgroups.

CONCLUSION

In the early years of real-world baricitinib use in the UK, a high proportion of patients continued with treatment at both 6 and 12 months, at which times disease activity was lower than at baseline.

A JAK Inhibitor for Treatment of Rheumatoid Arthritis: The Baricitinib Experience

Baricitinib, an oral selective Janus kinase (JAK)1/JAK2 inhibitor, is approved as monotherapy or in combination with methotrexate for treating adults with moderate-to-severe active rheumatoid arthritis (RA) and provides improvements in clinical signs, symptoms and patient-reported outcomes. Currently, baricitinib is approved for treating RA in more than 75 countries. In several pivotal Phase II and III RA trials (RA-BALANCE, RA-BEGIN, RA-BEAM, RA-BUILD, RA-BEACON, RA-BEYOND), up to seven years of baricitinib treatment was well tolerated and provided rapid and sustained efficacy, which was confirmed in real-world settings. Safety signals for another JAK inhibitor, tofacitinib, have emerged, as observed in the post-marketing Phase IIIb/IV trial Oral Rheumatoid Arthritis Trial (ORAL) Surveillance; safety signals were subsequently highlighted in a retrospective study of baricitinib and consequently new recommendations and warnings and precautions for all JAK inhibitors have been issued. Ongoing studies to further characterise and clarify the benefit:risk of JAK inhibitors include registries and controlled trials. This capstone review summarises clinical and real-world data outlining the benefit:risk profile of baricitinib, confirming that the improved disease activity and physical function of patients with RA treated with this JAK inhibitor observed in clinical trials is translated into effectiveness in clinical practice, with a low rate of discontinuations.

Baricitinib retention rate: 'real-life' data from a mono-centric cohort of patients affected by rheumatoid arthritis

Objectives

The aim of this retrospective study was to evaluate baricitinib retention rate in patients affected by rheumatoid arthritis. Secondary aims were to compare the impact on treatment persistence of monotherapy and other variables such as systemic corticosteroid use, line of treatment, disease duration, sex, biomarkers positivity, and Herpes Zoster virus infection.

Materials and methods

Patients with Rheumatoid Arthritis undergoing baricitinib were consecutively enrolled. Rheumatoid Arthritis diagnosis was performed with 2010 ACR/EULAR classification criteria. The cohort's demographic, clinical and therapeutical data were retrospectively collected. The whole follow-up duration was 104 weeks.

Results

Ninety-five patients affected by rheumatoid arthritis and treated with baricitinib were consecutively enrolled. At the end of follow-up, the overall retention rate was 69.3%. No statistically significant difference in retention rate was observed between patients treated with baricitinib in monotherapy or in combination with methotrexate (p = 0.638) while patients undergoing a steroidal treatment showed a significantly reduced treatment retention (p = 0.028). Contrarily, patients treated with baricitinib as a first-line b/tsDMARD showed higher drug retention (p = 0.002) compared to further treatment lines. Steroid employment, steroid dosage and previous treatment with bDMARDs correlated with risk of treatment discontinuation and at univariate analysis (p = 0.028, p < 0.001, and p = 0.002 respectively). Multivariate analysis confirmed significance for higher steroid dosage and previous treatment with bDMARDs (p = 0.002 and p = 0.046). No adverse events such as deep venous thrombosis, pulmonary embolism or tubercular infection/reactivation were reported during the study observation.

Conclusion

Our data show a good baricitinib retention rate after 12 and 24 months of observation (75.1 and 69.3%, respectively). In our cohort, concomitant treatment with methotrexate did not influence treatment persistence while retention was reduced in patients undergoing a steroidal treatment and/or in multi-failure subjects.

Tailored therapeutic decision of rheumatoid arthritis using proteomic strategies: how to start and when to stop?

Unpredictable treatment responses have been an obstacle for the successful management of rheumatoid arthritis. Although numerous serum proteins have been proposed, there is a lack of integrative survey to compare their relevance in predicting treatment outcomes in rheumatoid arthritis. Also, little is known about their applications in various treatment stages, such as dose modification, drug switching or withdrawal. Here we present an in-depth exploration of the potential usefulness of serum proteins in clinical decision-making and unveil the spectrum of immunopathology underlying responders to different drugs. Patients with robust autoimmunity and inflammation are more responsive to biological treatments and prone to relapse during treatment de-escalation. Moreover, the concentration changes of serum proteins at the beginning of the treatments possibly assist early recognition of treatment responders. With a better understanding of the relationship between the serum proteome and treatment responses, personalized medicine in rheumatoid arthritis will be more achievable in the near future.

Efficacy of Janus kinase inhibitors in rheumatoid arthritis

BACKGROUND

Janus kinase inhibitors (JAKis) is a new therapeutic class in autoimmune and inflammatory diseases. Four molecules are approved in rheumatoid arthritis (RA) in Europe. Recently, questions have raised about adverse events. In this context, a synthesis of the efficacy data of JAKis in RA is of use.

METHOD

We performed a literature review based on published articles about efficacy of JAKis in RA, including clinical trials, registries, retrospective and prospective cohorts as well as database analysis.

RESULTS

Based on the phase III clinical trials, JAKis are effective in comparison to placebo, methotrexate and tumour necrosis factor inhibitors. Based on registries, cohorts and post hoc analysis of phase III clinical trials, several parameters might modulate the efficacy of JAKis: the serological status, a short duration of the disease or the presence of poor prognostic factors. Preliminary data suggest that early ultrasonographic evaluation might help to predict the medium-term progression.

CONCLUSION

Some clinical, biological and imaging parameters seem to influence the response to JAKis and should be evaluated in larger studies. In addition to factors that might influence the efficacy of JAKis, the safety profile and risk factors should be considered before initiating JAKis in a patient.

Herpes zoster in patients with inflammatory arthritides or ulcerative colitis treated with tofacitinib, baricitinib or upadacitinib: a systematic review of clinical trials and real-world studies

JAK inhibitors (JAKi) are new targeted-synthetic drugs, approved for various immune-mediated inflammatory diseases (IMIDs), including inflammatory arthritides (rheumatoid arthritis-RA, psoriatic arthritis-PsA, ankylosing spondylitis-AS) and ulcerative colitis (UC). JAKi have been associated with increased risk for herpes zoster (HZ), but the relative risk among different JAKi in these IMIDs remains unclear. We aimed to systematically review the incidence of HZ among RA, PsA, AS and UC patients treated with the approved doses of tofacitinib (TOFA), baricitinib (BARI) or upadacitinib (UPA). PubMed, Embase, Scopus, Cochrane and Web-of-Science were searched up to 30 March 2022. Clinical trials and real-world studies (RWS) were included. Outcomes assessed were the incidence rate (/100 patient-years) or/and cumulative incidence of HZ. From 1710 records, 53 clinical trials and 25 RWS were included (RA: 54, PsA: 8, AS: 4, and UC: 12). In clinical trials, the HZ-incidence was higher in TOFA-treated patients with RA (2.2-7.1/100 patient-years) or UC (1.3-7.6/100 patient-years) compared to PsA (1.7/100 patient-years), and with higher doses of TOFA in UC (10 mg/twice daily: 3.2-7.6/100 patient-years vs. 5 mg/twice daily: 1.3-2.3/100 patient-years). Evidence for HZ-risk in JAKi-treated patients with AS and in UPA-treated patients was limited. The HZ-incidence between TOFA and BARI groups in 2 RA RWS did not differ significantly. Concomitant glucocorticoid, but not methotrexate, use in RA increased the HZ-risk. This systematic review showed higher HZ-risk in RA or UC than PsA patients treated with TOFA, in those treated with higher TOFA doses or with concomitant glucocorticoids. Preventive measures and monitoring of JAKi-treated patients with IMIDs are essential in daily practice.

The RA-BE-REAL Multinational, Prospective, Observational Study in Patients with Rheumatoid Arthritis Receiving Baricitinib, Targeted Synthetic, or Biologic Disease-Modifying Therapies: a 6-Month Interim Analysis

INTRODUCTION

RA-BE-REAL has the overall aim of defining a profile of patients with rheumatoid arthritis (RA) starting baricitinib or any other targeted synthetic (ts) or any biologic (b) disease-modifying antirheumatic drug (DMARD) for the first time, and the primary objective of estimating time until discontinuation from any cause (excluding sustained response) of the initial treatment.

METHODS

RA-BE-REAL is an ongoing, prospective, observational, 36-month study in patients with RA initiating treatment with baricitinib (cohort A) or any other tsDMARD or any bDMARD (cohort B) for the first time. The primary objective is to assess the time until treatment discontinuation from any cause (excluding sustained response) at 24 months, (i.e., the rate of discontinuation of initial baricitinib or ts/bDMARD). Patient profiles of each cohort are described and compared. Post-baseline data are descriptively analyzed. This manuscript presents baseline and interim (6-month) outcomes for European patients with RA participating in the global RA-BE-REAL study.

RESULTS

Data from 1074 patients (cohort A: 509; cohort B: 565) were analyzed. For cohorts A and B, respectively, the 6-month cumulative incidence (95% confidence interval) of treatment discontinuation was 16.5 (12.9-21.1) and 23.3 (19.1-28.2), and the proportions of patients achieving remission were 25.6% and 18.5%. At baseline, mean patient age was 59.1 and 57.0 years (p = 0.010) and mean disease duration was 10.0 and 8.9 years (p = 0.047), respectively. The proportions of patients exposed to ts/bDMARDs at any time before study entry were 51.9% and 39.1%, and the proportions of patients initiated on monotherapy were 50.9% and 31.2%, respectively.

CONCLUSION

In real-world settings, patients with RA initiating treatment with baricitinib were older and had longer disease duration than those initiating treatment with any other tsDMARD or any bDMARD. Initial descriptive data regarding treatment discontinuation (including reasons for discontinuation), effectiveness, and treatment patterns will be enriched as the study progresses.

Toward Overcoming Treatment Failure in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by inflammation and bone erosion. The exact mechanism of RA is still unknown, but various immune cytokines, signaling pathways and effector cells are involved. Disease-modifying antirheumatic drugs (DMARDs) are commonly used in RA treatment and classified into different categories. Nevertheless, RA treatment is based on a "trial-and-error" approach, and a substantial proportion of patients show failed therapy for each DMARD. Over the past decades, great efforts have been made to overcome treatment failure, including identification of biomarkers, exploration of the reasons for loss of efficacy, development of sequential or combinational DMARDs strategies and approval of new DMARDs. Here, we summarize these efforts, which would provide valuable insights for accurate RA clinical medication. While gratifying, researchers realize that these efforts are still far from enough to recommend specific DMARDs for individual patients. Precision medicine is an emerging medical model that proposes a highly individualized and tailored approach for disease management. In this review, we also discuss the potential of precision medicine for overcoming RA treatment failure, with the introduction of various cutting-edge technologies and big data.

Factors affecting drug retention of Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study

This multi-center, retrospective study aimed to clarify the factors affecting drug retention of the Janus kinase inhibitors (JAKi) including baricitinib (BAR) and tofacitinib (TOF) in patients with RA. Patients were as follows; females, 80.6%; age, 60.5 years; DAS28-ESR, 4.3; treated with either BAR (n = 166) or TOF (n = 185); bDMARDs- or JAKi-switched cases (76.6%). The reasons for drug discontinuation were classified into four major categories. The drug retention was evaluated at 24 months using the Kaplan–Meier method and multivariate Cox proportional hazards modelling adjusted by confounders. Discontinuation rates for the corresponding reasons were as follows; ineffectiveness (22.3%), toxic adverse events (13.3%), non-toxic reasons (7.2%) and remission (0.0%). Prior history of anti-interleukin-6 receptor antibody (aIL-6R) ineffectiveness significantly increased the risk of treatment discontinuation due to ineffectiveness (p = 0.020). Aging (≥ 75 years) (p = 0.028), usage of PSL ≥ 5 mg/day (p = 0.017) and female sex (p = 0.041) significantly increased the risk of treatment discontinuation due to toxic adverse events. Factors not associated with treatment discontinuation were: number of prior bDMARDs or JAKi, concomitant MTX usage, difference of JAKi, and prior use of TNF inhibitor, CTLA4-Ig or other JAKi.

How effective are JAK-inhibitors? Perspectives from clinical trials and real-world studies

INTRODUCTION

JAK-inhibitors have emerged as a new treatment option for rheumatoid arthritis, with five molecules currently available in different parts of the world: tofacitinib, baricitinib, upadacitinib, peficitinib, and filgotinib. These molecules have been the subject of numerous trials looking at their efficacy (how well they perform in controlled conditions) but also some observational studies from the general population to assess their effectiveness (how well treatment perform under real conditions). With each their own weaknesses and strengths, they give different but complementary information.

AREAS COVERED

We will review what we can learn from trials and real-world studies on how effective JAK-inhibitors are in the treatment of rheumatoid arthritis.

EXPERT OPINION

Trials of JAK-inhibitors have shown that JAK-inhibitors are efficacious for the treatment of rheumatoid arthritis. However, their main outcomes are not clinically meaningful as their aim is mainly the regulatory authorization of the product. Real-world studies are important as they evaluate the real-life effectiveness of the compounds, however, they are scarce at the moment, mainly evaluating tofacitinib and of variable quality. Future high-quality studies are needed to assess the real-world effectiveness of JAK-inhibitors in a more complete manner.

Comparison of the effects of baricitinib and tocilizumab on disease activity in patients with rheumatoid arthritis: a propensity score matching analysis

OBJECTIVE

This study aimed to compare the effects of baricitinib, a Janus kinase inhibitor, and tocilizumab, a monoclonal anti-interleukin-6 receptor antibody, on disease activity in patients with rheumatoid arthritis (RA), and to investigate the influence of inflammation on improvement in patient global assessment (PGA) of disease activity.

METHODS

This study was performed based on data from a multicenter registry, and included 284 and 113 patients treated with tocilizumab and baricitinib, respectively, who were observed for longer than 24 weeks. Propensity score matching was performed to address potential treatment-selection bias. To assess the influence of inflammation on PGA, patients were divided into two groups based on whether or not they achieved improvement in C-reactive protein (CRP, an objective marker of inflammation) at 24 weeks.

RESULTS

A total of 48 matched pairs of patients were identified. Compared to treatment with tocilizumab, baricitinib showed a similar improvement in tender and swollen joint count and serum CRP levels, and a significantly greater improvement in PGA at 24 weeks. As a result, the baricitinib group had a significantly higher proportion of patients who achieved Boolean remission at 24 weeks. In subgroups of patients who did not achieve 50% or 70% CRP improvement, significant decreases from baseline to 24 weeks were observed in PGA in patients treated with baricitinib, but not in those treated with tocilizumab.

CONCLUSION

Compared to tocilizumab, baricitinib significantly improved PGA despite similar effects on inflammation in patients with RA. Moreover, the influence of inflammation on PGA improvement differed between baricitinib and tocilizumab. Key-points • Baricitinib and tocilizumab had similar effects on inflammation in RA patients. • Baricitinib improved patient global assessment (PGA) more than tocilizumab. • Baricitinib had a higher Boolean remission rate than tocilizumab at 24 weeks. • Influence of inflammation on PGA improvement differed between the two drugs.

Autoantibodies in Rheumatoid Arthritis - Laboratory and Clinical Perspectives

Measurement of two groups of autoantibodies, rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) have gained increasing significance in the diagnosis and classification of rheumatoid arthritis (RA) over the last 65 years. Despite this rising importance of autoimmune serology in RA, there is a palpable lack of harmonization between different commercial RF and ACPA tests. While a minimal diagnostic specificity has been defined for RF tests, which almost always are related to an international reference preparation, neither of this applies to ACPA. Especially assays with low diagnostic specificity are associated with very low positive predictive values or post-test probabilities in real world settings. In this review we focus on issues of practical bearing for the clinical physician diagnosing patients who potentially have RA, or treating patients diagnosed with RA. We advocate that all clinically used assays for RF and ACPA should be aligned to a common diagnostic specificity of 98-99% compared to healthy controls. This high and rather narrow interval corresponds to the diagnostic specificity seen for many commercial ACPA tests, and represents a specificity that is higher than what is customary for most RF assays. Data on antibody occurrence harmonized in this way should be accompanied by test result-specific likelihood ratios for the target diagnosis RA on an ordinal or interval scale, which will provide the clinical physician with more granular and richer information than merely relating numerical values to a single cut-off point. As many physicians today are used to evaluate autoantibodies as positive or negative on a nominal scale, the introduction of test result-specific likelihood ratios will require a change in clinical mindset. We also discuss the use of autoantibodies to prognosticate future arthritis development in at-risk patients as well as predict severe disease course and outcome of pharmacological treatment.