Patient-Specific Femoral Guide with 3-Dimensional Support Software in Anterolateral Supine Approach of Total Hip Arthroplasty: A Single-Arm Trial.

Currently, there is no surgical assistance system that can perform a three-dimensional (3D) planned total hip arthroplasty (THA) by methods other than surgical assistance navigation or robots. However, they are expensive, cumbersome, and subject to additional invasiveness, so there is a need for a simpler and less expensive 3D surgical support system. In this study, THA was performed using the anterolateral approach (Watson-Jones) in the supine position in 23 subjects to examine the efficacy and safety of a patient-specific femoral guide linked to 3D surgery support software. In 48% of the subjects, the difference in anterior torsion angle from the preoperative plan was within ±5 degrees, while in 83% of the subjects, the difference was within ±10 degrees. The 95% confidence interval (4.61-8.70) of the absolute difference did not fall below the pre-defined threshold of 7.2 degrees (p = 0.293). No adverse events were observed other than 2 cases (8.7%) of hemorrhage that required a blood transfusion. We confirmed the efficacy and safety of the patient-specific femoral guide in anterolateral supine approach THA.

The Efficacy and Safety of a Novel Extramedullary Guide Coordinated with 3D Surgical Assistive Software for Total Knee Arthroplasty: an Open-Label Single-Arm Trial.

To improve component-placement accuracy in total knee arthroplasty, we developed two devices: an original extramedullary patient-specific guide for the femur and an original extramedullary universal guide for the tibia (EM-TIBIA). We also developed a new function in ZedView, a three-dimensional surgical assistive software, that provides the parameters necessary to install the EM-TIBIA. Compared with conventional manual methods based on X-ray two-dimensional images or ZedView, these newly developed devices function as an extramedullary intraoperative support guide in conjunction with ZedView, simplifying surgical procedures. We conducted a study to evaluate the efficacy and safety of the surgery using the new guides and software function. Nineteen patients underwent surgery. On the femoral side, the mean absolute difference of the installation alignment was within 3° for all parameters. On the other hand, on the tibial side, the mean absolute difference from the preoperative plan for the rotation was 5.26±5.30°. The proportion of patients whose difference fell within ±3° was 52.6% (95% confi dence interval: 28.9 to 75.6%), and did not meet the pre-specified criteria for efficacy (P=0.261). No serious adverse events were reported, and no excessive bleeding, thrombosis, infections, or intraoperative or postoperative fractures were noted. The two new guides can easily reproduce the preoperative plan as 3D intraoperative support jigs, but errors can occur on the tibia side due to soft tissue that is not recognized by CT, creating problems in installation accuracy.

A retrospective analysis of the relationship between anti-cyclic citrullinated peptide antibody and the effectiveness of abatacept in rheumatoid arthritis patients.

This study aimed to evaluate the effectiveness of abatacept (ABA) by anti-cyclic citrullinated peptide (ACPA) status on disease activity as well as radiographic progression in patients with rheumatoid arthritis (RA) in clinical settings. A retrospective cohort study was conducted using data from a multicenter registry. Data from a total of 553 consecutive RA patients treated with intravenous ABA were included. We primarily compared the status of disease activity (SDAI) and radiographic progression (van der Heijde modified total Sharp score: mTSS) between the ACPA-negative (N = 107) and ACPA-positive (N = 446) groups. 'ACPA positive' was defined as ≥ 13.5 U/mL of anti-CCP antibody. Baseline characteristics between groups were similar. The proportion of patients who achieved low disease activity (LDA; SDAI ≤ 11) at 52 weeks was significantly higher in the ACPA-positive group. Multivariate logistic regression analysis identified ACPA positivity as an independent predictor for achievement of LDA at 52 weeks. Drug retention rate at 52 weeks estimated by the Kaplan-Meier curve was significantly higher in the ACPA-positive group. Achievement rate of structural remission (ΔmTSS ≤ 0.5) at 52 weeks was similar between groups. ABA treatment demonstrated a significantly higher clinical response and higher drug retention rate in ACPA-positive patients. Progression of joint destruction was similar between the ACPA-negative and ACPA-positive groups. Close attention should be paid to joint destruction even in patients showing a favorable response to ABA, especially when the ACPA status is positive.

Improvement in matrix metalloproteinase-3 independently predicts low disease activity at 52 weeks in bio-switch rheumatoid arthritis patients treated with abatacept.

OBJECTIVES: To explore predictive factors including MMP-3 for achievement of low disease activity (LDA) at 52 weeks in bio-switch rheumatoid arthritis (RA) patients treated with abatacept, for whom obtaining a good clinical response can be difficult. METHODS: Participants were 423 consecutive patients with RA treated with abatacept who were observed for longer than 52 weeks and registered in the TBCR, a Japanese multicentre registry system. Multivariate logistic regression analysis was used to study factors that predict the achievement of LDA at 52 weeks in bio-naïve (n=234) and bio-switch (n=189) groups. RESULTS: ROC analysis revealed that MMP-3 improvement rates at 12 weeks in bio-switch patients had the highest AUC with a cut-off value of 20.0% for predicting LDA achievement at 52 weeks. Multivariate logistic regression analysis revealed that, in addition to DAS28-CRP at baseline, achieving 20% improvement in MMP-3 levels at 12 weeks was an independent predictive factor (adjusted OR: 4.277, p=0.003) in the bio-switch group, whereas DAS28 was the only predictor in the bio-naïve group. Patients who achieved 20% improvement in MMP-3 levels at 12 weeks had significantly higher achievement rates of LDA at 52 weeks compared to those who did not achieve 20% improvement in the bio-switch group (60.0 vs. 33.3%, p=0.001). CONCLUSIONS: Our findings suggest that improvement in MMP-3 levels is key to predicting the clinical efficacy of abatacept. Closer attention paid not only to major clinical indices, but also changes in MMP-3 levels, could improve our ability to optimise clinical results when treating bio-switch patients.

Clinical effectiveness and safety of additional administration of tacrolimus in rheumatoid arthritis patients with an inadequate response to abatacept: A retrospective cohort study.

OBJECTIVE: Abatacept (ABT) demonstrates good clinical efficacy and retention in rheumatoid arthritis (RA) patients. However, no rescue treatment option against inadequate response to ABT exists. Since tacrolimus (TAC) and ABT suppress T lymphocytes via different mechanisms and a combination of these agents could potentially be effective, this study aimed to examine the efficacy and safety of add-on TAC therapy in RA patients with inadequate response to ABT. METHODS: Of 550 patients treated with ABT and registered in a Japanese multicenter registry, 25 consecutive patients who underwent add-on TAC therapy and were followed for longer than 24 weeks were included in this study. RESULTS: Mean patient age was 67.0 years, disease duration was 16.2 years, and duration of ABT treatment was 1.2 years at the initiation of add-on TAC therapy. Mean TAC dose was 1.2 mg/d at baseline and 1.6 mg/d at week 24. Mean Disease Activity Score of 28 joints - erythrocyte sedimentation rate was significantly improved at week 24 (3.35) relative to baseline (4.97). The proportion of patients who achieved low disease activity or remission was 40.0%, and the European League Against Rheumatism moderate or good response was 72.0%. ABT retention rate was 92.0% at week 24, as calculated by Kaplan-Meier analysis. Only one patient discontinued add-on TAC therapy due to an adverse event (itching sensation). CONCLUSION: This is the first report describing the efficacy and safety profile of add-on TAC therapy with a focus on RA patients with inadequate response to ABT. Our findings suggest that add-on TAC therapy is a worthwhile complementary treatment option in daily clinical practice.

Concomitant methotrexate has little effect on clinical outcomes of abatacept in rheumatoid arthritis: a propensity score matching analysis.

OBJECTIVE: To compare the clinical outcomes of abatacept between rheumatoid arthritis patients with and without concomitant methotrexate (MTX) treatment in daily clinical practice. METHODS: A retrospective cohort study was performed using data from a multicentre registry. A total of 176 consecutive rheumatoid arthritis patients treated with abatacept were included. The propensity score based on multiple baseline characteristic variables was calculated, and 41 of 86 patients treated without MTX (MTX(-)) and 41 of 90 patients treated with concomitant MTX (MTX(+)) were statistically extracted and analysed. Clinical outcomes were evaluated and compared between the two groups over a 52-week period. RESULTS: Baseline characteristics were statistically comparable. No significant differences were observed in the following clinical outcomes from baseline throughout the 52-week period: drug retention rate (MTX(-)/MTX(+) 79.1%/80.5%), mean change in disease activity score based on 28 joints (DAS28-CRP) from baseline (- 1.35/- 1.54), low disease activity rate (48.8%/43.9%), clinical remission rate (31.7%/36.6%), moderate European League Against Rheumatism (EULAR) response rate (68.3%/68.3%), and good EULAR response rate (36.6%/41.1%) at 52 weeks. CONCLUSION: In rheumatoid arthritis patients with similar background characteristics undergoing abatacept treatment, concomitant MTX does not seem to affect clinical outcomes. Abatacept would be a suitable treatment option in daily clinical practice in patients with contraindications to MTX. KEY POINTS: • This is the first study to directly compare the clinical efficacy and safety of abatacept between patients with and without concomitant methotrexate (MTX) treatment in 'real-world' settings using the propensity score matching method. • There were no significant differences in clinical outcomes of abatacept between patients with and without concomitant MTX treatment. • We used data from a large Japanese multicentre registry for biologics in rheumatoid arthritis, thereby decreasing selection bias based on the personal preferences of physicians.

Normal serum matrix metalloproteinase-3 levels can be used to predict clinical remission and normal physical function in patients with rheumatoid arthritis.

This study aimed to evaluate whether normal serum matrix metalloproteinase-3 (MMP-3) levels can be used to predict clinical remission and normal physical function at a single time point when treating patients with rheumatoid arthritis (RA) in daily practice settings. Subjects were all 1321 RA patients who were treated at our hospital. The accuracy of serum MMP-3 levels was larger than those of C-reactive protein (CRP) levels for predicting clinical remission [Simplified Disease Activity Index (SDAI) ≤ 3.3], normal function [Disability Index of the Health Assessment Questionnaire (HAQ-DI) ≤ 0.5], and both in clinical remission and with normal function (clinical remission + normal function) using receiver operating characteristic curve analysis. Serum MMP-3 levels were significantly correlated with CRP levels [r 0.229 (men), r 0.476 (women)] using Pearson's correlation coefficients. Among patients with normal CRP levels (n = 807), the percentage of patients in clinical remission, with normal function, and with clinical remission + normal function having normal serum MMP-3 levels was significantly higher than those with abnormal serum MMP-3 levels. In addition, among patients with the 28-point count Disease Activity Score-CRP (DAS28-CRP) remission (DAS28-CRP < 2.3), the percentage of patients in clinical remission, with normal function, and with clinical remission + normal function having normal serum MMP-3 levels was significantly higher than those with abnormal serum MMP-3 levels. Our findings suggest that normal serum MMP-3 levels, in combination with CRP levels or disease activity, are useful for predicting clinical remission and normal physical function in patients with RA.

Clinical effectiveness and long-term retention of abatacept in elderly rheumatoid arthritis patients: Results from a multicenter registry system.

Objective: To study the clinical effectiveness and long-term retention rate of abatacept (ABA) in elderly rheumatoid arthritis (RA) patients in daily clinical practice.Methods: A retrospective cohort study was performed using data from a multicenter registry. Our study population comprised 500 consecutive RA patients treated with ABA. We compared clinical effectiveness and ABA retention rates between the Young (≤62 years), Middle (62 to 72 years), and Elderly (≥72 years) groups. We also performed separate examinations to identify predictive factors for ABA discontinuation in those with versus those without concomitant methotrexate (MTX) treatment.Results: Mean age was 52.7 years in the Young group, 67.7 years in the Middle group, and 78.1 years in the Elderly group. No significant group-dependent differences were found in mean DAS28 score, categorical distribution of DAS28, and EULAR response rate across the 52 weeks. The ABA retention rates at three years as determined by the Kaplan-Meier method were similar in all three groups. Patient age was not a significant predictor of ABA discontinuation due to adverse events in patients with concomitant MTX; however, it was found to be a significant predictor for those who did not use MTX (Cox hazard model).Conclusion: ABA would be a reasonable treatment option for elderly RA patients from the viewpoints of both clinical effectiveness and long-term retention. However, physicians should watch carefully for any serious adverse reactions in elderly RA patients with intolerance to MTX.

An Open-Label, Single-Arm Study of a Patient-Specific Femoral Guide for Total Hip Arthroplasty via the Anterolateral Supine Approach, Linked with Three-Dimensional Surgical Support Software: Study Protocol.

In total hip arthroplasty (THA), it is generally accepted that the bones of the acetabular cup and femur of hip joint must be accurately cut and components (artificial joint parts) be implanted in exact positions at exact angles to achieve improvement of daily living (ADL) and quality of life (QOL). However, with the conventional surgical method, it is difficult to grasp and measure the acetabular cup and femoral stem precisely during surgery, making some kind of reliable guide necessary. Although it was reported that an accurate angle was achieved in acetabular cup implantation by support instruments for surgical planning, an effective support instrument is now being developed for stem implantation on the out-of-reach femur side. This is the first clinical study to assess the efficacy and safety of anterolateral approach THA using an extracorporeal patient-specific femoral guide (PSG) for stem implantation with three-dimensional (3D) surgical support software in patients with hip joint disease.

An Open-label Single-arm Trial of a Novel Extramedullary Guide Coordinated with 3D Surgical Assistive Software for Total Knee Arthroplasty.

There is no assistive device for extramedullary surgery coordinated with 3D surgical assistive software for the total knee arthroplasty (TKA). We developed a novel extramedullary universal guide coordinated with 3D surgical assistive software and a novel extramedullary patient-specific assistive guide for the placement of femoral components by referring to an area not affected by cartilage or bone spurs, and filed a patent application. In this study, we visualize and reconstruct the total alignment of the lower extremity in TKA using these surgical devices, and validate their precision. A report releasing study results will be submitted in an appropriate journal.

Hospital Anxiety and Depression Scale Score Is an Independent Factor Associated With the EuroQoL 5-Dimensional Descriptive System in Patients With Rheumatoid Arthritis.

OBJECTIVE: This study aimed to examine anxiety and depression experienced by patients with rheumatoid arthritis (RA) using EuroQoL 5-Dimensional Descriptive System (EQ-5D) and Hospital Anxiety and Depression Scale (HADS) scores. METHODS: We analyzed 1005 Japanese patients with RA. Stepwise multiple linear regression analysis was performed to evaluate the independent influence of variables on EQ-5D and HADS scores. Pearson correlation coefficients were also calculated to explore relationships between variables. RESULTS: The mean EQ-5D score was 0.74 for all patients (mean age, 63.2 years; mean disease duration, 13.6 years; mean Health Assessment Questionnaire Disability Index [HAQ-DI], 0.78; mean HADS total [HADS-T] score, 10.3; mean disease activity score assessed by 28 joints based on CRP [DAS28-CRP], 2.8). The EQ-5D score was strongly correlated with HAQ-DI and was moderately correlated with age, Steinbrocker functional class, HADS-T score, tender joint count assessed by 28 joints, pain on a visual analog scale (pain-VAS), patient's global assessment of disease activity (general-VAS), and DAS28-CRP. The HADS-T score was moderately correlated with HAQ-DI, pain-VAS, general-VAS, and DAS28-CRP. Factors that influenced the EQ-5D score included HAQ-DI (ß = -0.533), pain-VAS (ß = -0.128), HADS-T score (ß = -0.142), DAS28-CRP (ß = -0.187), and prednisolone use (ß = -0.056). Factors that influenced the HADS score included HAQ-DI (ß = 0.348), general-VAS (ß = 0.145), disease duration (ß = 0.094), and worklessness (ß = 0.083). CONCLUSIONS: The HADS score is an independent factor associated with EQ-5D in patients with RA. Our findings suggest that the assessment of anxiety and depression is essential in achieving better quality of life for patients with RA.

High rate of improvement in serum matrix metalloproteinase-3 levels at 4 weeks predicts remission at 52 weeks in RA patients treated with adalimumab.

OBJECTIVE: This study aimed to determine whether serum matrix metalloproteinase-3 (MMP-3) levels can predict remission in rheumatoid arthritis (RA) patients treated with adalimumab (ADA). METHODS: Subjects were 114 RA patients continuously treated with ADA for 52 weeks. Predictive factors at baseline and 4 weeks after initiation of ADA therapy for the achievement of remission (28-point count Disease Activity Score-CRP (DAS28-CRP) < 2.3) at 52 weeks were evaluated by multivariate logistic regression analysis. RESULTS: DAS28-CRP at 4 weeks (odds ratio (OR) 0.614, 95% confidence interval (CI) 0.382-0.988) and improvement in serum MMP-3 levels at 4 weeks (OR 1.057, 95% CI 1.002-1.032) were independent predictors of remission at 52 weeks. The best cut-off level of DAS28-CRP and improvement in serum MMP-3 levels at 4 weeks for predicting remission at 52 weeks was 3.73 (sensitivity: 90%, specificity: 50%, area under the receiver operating characteristic curve (AUC): 62%) and 39.93% (sensitivity: 47%, specificity: 83%, AUC: 64%), respectively. CONCLUSION: Our findings suggest that a high rate of improvement in serum MMP-3 levels at 4 weeks after initiation of ADA therapy can predict remission at 52 weeks in RA patients.

Steroid therapy and renal dysfunction are independently associated with serum levels of matrix metalloproteinase-3 in patients with rheumatoid arthritis.

OBJECTIVE: This study aimed to evaluate whether the level of serum matrix metalloproteinase-3 (MMP-3), a marker of synovium inflammation, is affected by clinical characteristics of patients in rheumatoid arthritis (RA) patients. METHODS: We analyzed data from 1087 female patients with RA. Pearson's correlation coefficients were calculated to explore associations between variables. Stepwise multiple linear regression analysis was performed to evaluate patient background variables that could potentially affect serum MMP-3 levels. RESULTS: Serum MMP-3 was moderately correlated with C-reactive protein (CRP) (r: 0.478). Factors that independently influenced serum MMP-3 levels were CRP (ß: 0.450), prednisolone (PSL) use (ß: 0.100), estimated glomerular filtration rate (eGFR) (ß: -0.085), swollen joint count assessed on 28 joints (ß: 0.072), and body mass index (ß: -0.061) in female patients with RA. In RA patients with PSL use, factors that independently influenced serum MMP-3 levels were CRP (ß: 0.480), eGFR (ß: -0.175), and PSL dose (ß: 0.171). CONCLUSIONS: Our findings suggest that steroid therapy and renal dysfunction affect serum MMP-3 levels in patients with RA.

Comparison of physical function in early rheumatoid arthritis patients treated with biologics for 1 year who achieved clinical remission or low disease activity.

This study aimed to evaluate whether targeting clinical remission is appropriate for suppressing physical dysfunction in patients with early rheumatoid arthritis (RA). Subjects were all 75 early RA patients (within 2 years of onset) who were continuously treated with biologics for 12 months at our hospital. We evaluated the Simplified Disease Activity Index (SDAI) and Disability Index of the Health Assessment Questionnaire (HAQ-DI) at 3, 6, and 12 months from the initiation of biologics therapy. Rates of functional remission (HAQ-DI ≤ 0.5) at 12 months in the clinical remission (SDAI ≤ 3.3) group and the low disease activity [LDA (3.3 < SDAI ≤11)] group were 97 and 86%, respectively. Multivariate logistic regression analysis revealed that duration of disease and SDAI at 6 months were significantly associated with the achievement of functional remission at 12 months. The best cut-off value of SDAI at 6 months for predicting functional remission at 12 months was 15.7 by receiver operating characteristic curve analysis. HAQ-DI scores in the LDA group were significantly higher than those in the clinical remission group at 6 and 12 months. The mean HAQ-DI score at 12 months in the clinical remission group improved significantly relative to the mean HAQ-DI score at 6 months in the LDA group. Our findings highlight the importance of achieving LDA at least by 6 months after initiating biologics therapy, and achieving clinical remission as soon as possible, in order to minimize physical dysfunction in patients with early RA.

Longterm Retention Rate and Risk Factors for Adalimumab Discontinuation Due To Efficacy and Safety in Japanese Patients with Rheumatoid Arthritis: An Observational Cohort Study.

OBJECTIVE: To evaluate the rates of retention and discontinuation of adalimumab (ADA) due to efficacy and safety in Japanese patients with rheumatoid arthritis (RA). METHODS: All patients with RA (n = 476) who were treated with ADA in the Tsurumai Biologics Communication Registry were enrolled. RESULTS: The retention rate of ADA was 46% at 5 years. When focusing on insufficient efficacy, previous biologics use and high baseline disease activity were significant risk factors for up to 1 year. Methotrexate (MTX) use was a significantly low risk factor after 1 year of treatment. CONCLUSION: Concomitant MTX contributes to the longterm efficacy of ADA therapy.

Predictive factors for achieving low disease activity at 52 weeks after switching from tumor necrosis factor inhibitors to abatacept: results from a multicenter observational cohort study of Japanese patients.

This study aimed to identify predictive factors for achieving low disease activity (LDA) in rheumatoid arthritis (RA) patients switching from tumor necrosis factor inhibitors (TNFis) to abatacept (ABT). Patients who were registered in the multicenter observational Tsurumai Biologics Communication Registry (TBCR) were enrolled in this study. Predictive factors for LDA achievement at each time point were determined by univariate and multivariate logistic regression analyses. The cutoffs of 28-point count Disease Activity Score (DAS28)-C-reactive protein (CRP) and ΔDAS28-CRP from baseline up to 24 weeks for LDA achievement at 52 weeks were explored using receiver operating characteristic (ROC) curves. Of 2771 RA patients registered until 2013, 76 with moderate or high disease activity were selected. Twenty-six percent of the patients achieved LDA. Multivariate analysis confirmed that DAS28-CRP at 12 weeks and ΔDAS28-CRP from baseline to 12 weeks were independent factors for LDA achievement at 52 weeks [odds ratio (OR) 0.26, 95% confident interval (CI) (0.12-0.56), OR 0.25, 95% CI (0.11-0.57), respectively]. The best cutoff values of DAS28-CRP at 12 weeks and ΔDAS28-CRP from baseline to 12 weeks for LDA at 52 weeks were 3.9 (sensitivity 0.85, specificity 0.78) and -0.97 (sensitivity 0.70, specificity 0.70), respectively. Seventy-one percent of patients who achieved both of these cutoff values at 12 weeks achieved LDA at 52 weeks. Our findings suggest that the clinical course up to 12 weeks is important for predicting long-term outcomes when switching from TNFis to ABT.

Concomitant methotrexate and tacrolimus augment the clinical response to abatacept in patients with rheumatoid arthritis with a prior history of biological DMARD use.

This observational retrospective study examined whether abatacept efficacy could be augmented with concomitant methotrexate (MTX) or tacrolimus (TAC) in patients with rheumatoid arthritis (RA) who experienced failure with prior biological disease-modifying antirheumatic drugs (DMARDs) and in whom favorable therapeutic efficacy is difficult to achieve. All patients with a prior biological DMARD history who were treated with abatacept for 52 weeks and registered in a Japanese multicentre registry were included. Clinical efficacy and safety of abatacept according to the concomitant drug used, i.e., none (ABT-mono), MTX (ABT-MTX), and TAC (ABT-TAC), were compared. A greater mean percent change of DAS28-ESR was observed in the ABT-TAC group compared with the ABT-mono group at weeks 12 (-20.5 vs. -5.4 %, p = 0.035) and 24 (-25.0 vs. -11.0 %, p = 0.036). ABT-MTX and ABT-TAC groups had a significantly higher proportion of patients who achieved low disease activity (LDA) within 52 weeks compared with the respective baselines, while no significant change was observed in the ABT-mono group. A higher proportion of patients in the ABT-TAC group achieved EULAR moderate response compared with the ABT-mono group at week 52 (66.7 vs. 35.0 %, p = 0.025). Multivariate logistic regression analysis revealed that concomitant TAC use was independently associated with the achievement of LDA and EULAR response at 52 weeks, while concomitant MTX use was not. Concomitant TAC use may offer a suitable option for RA patients treated with abatacept after prior biological DMARD failure, likely because both abatacept and TAC affect T cell activation.

Sustainable Efficacy of Switching From Intravenous to Subcutaneous Tocilizumab Monotherapy in Patients With Rheumatoid Arthritis.

OBJECTIVE: To evaluate the efficacy and safety of switching from intravenous (IV) tocilizumab (TCZ) to subcutaneous (SC) TCZ monotherapy in rheumatoid arthritis patients. METHODS: Patients who had completed 24 weeks of TCZ-SC (162 mg/2 weeks) or TCZ-IV (8 mg/kg/4 weeks) monotherapy in the double-blind period of the MUSASHI study were enrolled in an 84-week open-label extension period. All received TCZ-SC (162 mg/2 weeks) monotherapy. Effects of the IV to SC switch were evaluated at week 36 (12 weeks after switching). RESULTS: Overall, 319 patients received ≥1 dose of TCZ-SC during the open-label extension period; 160 switched from TCZ-IV to TCZ-SC (TCZ IV/SC) and 159 continued TCZ-SC (TCZ SC/SC). Disease Activity Score in 28 joints using the erythrocyte sedimentation rate clinical remission rates were 62.5% (100 of 160) for TCZ IV/SC and 50.0% (79 of 158) for TCZ SC/SC at week 24, and were maintained at 62.5% (100 of 160) and 57.0% (90 of 158), respectively, at week 36. In the TCZ IV/SC group, 9% of patients (9 of 100) who had achieved remission at week 24 could not maintain remission at week 36. In TCZ IV/SC patients weighing ≥70 kg, the percentage with a sufficient serum TCZ concentration (≥1 µg/ml) decreased from 90.9% (10 of 11) at week 24 to 45.5% (5 of 11) at week 36. Overall safety profiles were similar in TCZ IV/SC and TCZ SC/SC except for mild injection site reactions in TCZ IV/SC. CONCLUSION: Efficacy is adequately maintained in most patients switching from TCZ-IV (8 mg/kg/4 weeks) to TCZ-SC (162 mg/2 weeks) monotherapy. Patients receiving TCZ-IV can switch to TCZ-SC without serious safety concerns. Clinical efficacy may be reduced after switching in some patients with high body weight.

Longterm efficacy and safety of abatacept in patients with rheumatoid arthritis treated in routine clinical practice: effect of concomitant methotrexate after 24 weeks.

OBJECTIVE: Our study aimed to evaluate the longterm efficacy and safety of abatacept (ABA), and to explore factors that increase its longterm efficacy in patients with rheumatoid arthritis (RA) treated in routine clinical practice. METHODS: There were 231 participants with RA treated with ABA who were prospectively registered in a Japanese multicenter registry. They were followed up for at least 52 weeks. RESULTS: Mean age of the patients was 64.3 years, mean disease duration was 12.1 years, mean 28-joint Disease Activity Score (DAS28)-C-reactive protein was 4.49, and 48.5% of patients were concomitantly treated with methotrexate (MTX). Overall retention rate of ABA was 77.1% at 52 weeks; 14.8% of patients discontinued because of inadequate response and 3.5% because of adverse events. The proportion of patients achieving DAS28-defined low disease activity (LDA) significantly increased from baseline to 52 weeks (7.3% to 43.8%, p < 0.01); 40.9% of patients who did not achieve LDA at 24 weeks had more than 1 categorical improvement in DAS28-defined disease activity at 52 weeks. Multivariate logistic regression revealed concomitant MTX use to be an independent predictor of the categorical improvement in DAS28-defined disease activity from 24 to 52 weeks (adjusted OR 3.124, p = 0.010). CONCLUSION: In routine clinical practice, ABA demonstrated satisfactory clinical efficacy and safety in patients with established RA for 52 weeks. The clinical efficacy of ABA increased with time even after 24 weeks, and this was strongly influenced by concomitant MTX use. Our study provides valuable real-world findings on the longterm management of RA with ABA.