Published papers

Objectives: This study investigated the effects of dose step-down in patients with rheumatoid arthritis (RA) who achieved sustained disease control with baricitinib 4 mg once a day. Methods: Patients who completed a baricitinib phase 3 study could enter a long-term extension (LTE). In the LTE, patients who received baricitinib 4 mg for ≥15 months and maintained CDAI low disease activity (LDA) or remission (REM) were blindly randomised to continue 4 mg or taper to 2 mg. Patients could rescue (to 4 mg) if needed. Efficacy and safety were assessed through 48 weeks. Results: Patients in both groups maintained LDA (80% 4 mg; 67% 2 mg) or REM (40% 4 mg; 33% 2 mg) over 48 weeks. However, dose reduction resulted in small, statistically significant increases in disease activity at 12, 24 and 48 weeks. Dose reduction also produced earlier and more frequent relapse (loss of step-down criteria) over 48 weeks compared with 4 mg maintenance (23% 4 mg vs 37% 2 mg, p=0.001). Rescue rates were 10% for baricitinib 4 mg and 18% for baricitinib 2 mg. Dose reduction was associated with a numerically lower rate of non-serious infections (30.6 for baricitinib 4 mg vs 24.9 for 2 mg). Rates of serious adverse events and adverse events leading to discontinuation were similar across groups. Conclusions: In a large randomised, blinded phase 3 study, maintenance of RA control following induction of sustained LDA/REM with baricitinib 4 mg was greater with continued 4 mg than after taper to 2 mg. Nonetheless, most patients tapered to 2 mg could maintain LDA/REM or recapture with return to 4 mg if needed.

Objective: Evaluate the safety and efficacy of golimumab through week 120 in Japanese patients with active rheumatoid arthritis (RA) previously treated with DMARDs. Methods: Japanese patients with active RA despite prior DMARDs were randomized to placebo (Group 1, n = 105), golimumab 50 mg (Group 2, n = 101), or golimumab 100 mg (Group 3, n = 102). At week 16, Group 1 patients crossed over to golimumab 50mg; after week 52, a one-time golimumab dose reduction from 100 to 50 mg was permitted. Assessments included ACR20/50/70 responses and good/moderate DAS28-ESR responses. Radiographic progression was assessed with the van der Heijde-modified Sharp (vdH-S) score. Safety and efficacy were assessed through week 120. Results: ACR20 response rates at week 52 in Group 1, Group 2, and Group 3 were 70.6%, 71.4%, and 81.9%, respectively, and maintained through week 104 (87.2%, 85.1%, 88.9%, respectively) and week 120 (86.1%, 87.0%, 89.5%, respectively). Similar trends were observed for ACR50, ACR 70, and DAS28-ESR. Median change in total vdH-S at weeks 52, 104, and 120 ranged from 0.0 to 1.5 across treatment groups. Through week 120, 93.8%/97.1% had an AE with golimumab 50 mg/100 mg, respectively, and 19.7%/11.8% had an SAE. Infections were the most common AE. Conclusion: Clinical response to golimumab 50 mg and 100 mg was maintained over 2 years in Japanese patients with active RA despite prior DMARDs.

Objective: To evaluate the sustained remission and low disease activity after discontinuation of tocilizumab in patients with rheumatoid arthritis who were treated with tocilizumab alone or in combination with methotrexate. Methods: The SURPRISE study was a 2-year, open-label randomised controlled study. Among patients who had been randomised to additional tocilizumab (ADD-ON) or switch to tocilizumab (SWITCH) in the first year, those who achieved remission based on the disease activity score for 28 joints (DAS28-ESR<2.6) discontinued tocilizumab at week 52 and were observed for the following 52 weeks. The endpoint of the second year included tocilizumab-free remission and low disease-Activity rates, functional outcome, radiological outcomes assessed with the modified total Sharp score (mTSS) and safety. The efficacy of reinstituted tocilizumab/methotrexate was also evaluated. Results: A total of 105 patients who achieved remission at week 52 discontinued tocilizumab; 51 in ADD-ON continued methotrexate and 54 in SWITCH received no disease-modifying antirheumatic drugs. Sustained DAS28 low disease-Activity rates were significantly higher in ADD-ON than in SWITCH (55%vs27%, p=0.005). Sustained remission rates at week 104 were 24% for ADD-ON and 14% for SWITCH (p=0.29). Radiological progression was comparable between both groups (mTSS; 0.37vs0.64, p=0.36). The restart of tocilizumab induced remission in all except two patients after 36 weeks, irrespective of concomitant methotrexate. Conclusion: Sustained low disease activity after tocilizumab discontinuation could be maintained with continued methotrexate in more than half of the patients. Retreatment with tocilizumab led to remission in more than 90% of patients. Trial registration number: NCT01120366; Results.

Objective: To evaluate the efficacy and safety of sirukumab, a human anti-interleukin six monoclonal antibody, in Japanese patients with rheumatoid arthritis who were refractory to anti-tumor necrosis factor therapy. Methods: This subgroup analysis, based on a double-blind, placebo-controlled, 52-week phase 3, global study (SIRROUND-T) assessed the American College of Rheumatology (ACR) 20 response at week 16 (primary endpoint). Secondary endpoints: ACR 50, Disease Activity Score in 28 joints-C reactive protein, Health Assessment Questionnaire-Disability Index and safety were assessed. Results 116/878 patients received sirukumab 50 mg/4 weeks (q4w, n = 35), 100 mg/2 weeks (q2w, n = 44) or placebo (n = 37) subcutaneously. Significantly more patients achieved ACR 20 response at week 16 with sirukumab (50 mg q4w:20 [57.1%]; p < .001, 100 mg q2w:24 [54.5%]; p = .001) versus placebo (7 [18.9%]); consistent significant improvement in secondary endpoints at week 24 and 52 was observed. At week 24, incidence of treatment-emergent adverse events (TEAEs) was numerically higher with sirukumab groups (50 mg q4w:29 [82.9%]; 100 mg q2w:38 [86.4%] versus placebo (28 [75.7%]); however, at week 52, sirukumab combined groups had comparable incidence of TEAEs. Conclusion: Efficacy findings through 52 weeks were comparable between sirukumab doses in Japanese patients and consistent with primary SIRROUND-T study results. No new safety signals were observed.

IgG4-related disease is a heterogeneous immune-mediated fibroinflammatory condition that can affect every single organ. This disease is more prevalent in the elderly (the mean age of patients is above 60 years) and the prevalence rate is estimated to be over 4.6 per 100,000 population. Before making a diagnosis, the exclusion of malignancies, lymphoma, anti-neutrophil cytoplasmic antibody-associated vasculitis, multicentric Castleman disease, and other mimickers is crucial for appropriate treatment. Broad management guidelines have been published emphasizing the need for prompt treatment and the use of glucocorticoids as first-line drug therapy for induction of remission. However, the toxic effects of glucocorticoids are problematic because IgG4-related disease is more prevalent in patients above 60 years of age, a population with frequent comorbid conditions and polypharmacy. Immunosuppressants (cyclophosphamide, methotrexate, leflunomide, and tacrolimus) and targeted immunomodulators (rituximab, XmAb5871, and abatacept) are appealing to overcome potential toxic effects of glucocorticoids and as emerging glucocorticoid-sparing and/or maintenance treatments. In this review, we provide an overview of our understanding of the pathophysiology of the disease (T follicular helper cells, CD4+ cytotoxic T cells, plasmablasts, and alternatively activated M2 macrophages) and clinical characteristics, and highlight the potential targets for treatment intervention.

Background: Sirukumab, a high-affinity human monoclonal antibody that selectively binds to interleukin-6, has demonstrated efficacy in the treatment of rheumatoid arthritis (RA) in global phase 1 and phase 2 studies. The present study evaluated the safety and efficacy of sirukumab, as monotherapy in Japanese patients with RA refractory to methotrexate or sulfasalazine. Methods: In this phase 3, double-blind study, 122 patients (age ≥ 20 years) were randomized (1:1, 61 patients in each arm) to sirukumab administered subcutaneously: 50 mg once every 4 weeks (q4w) or 100 mg once every 2 weeks (q2w) through 52 weeks. Disease-modifying anti-rheumatic drugs were allowed after 24 weeks. Safety was assessed and efficacy was evaluated using American College of Rheumatology (ACR) responses, Disease Activity Score C-reactive protein (DAS28-CRP) and Health Assessment Questionnaire-Disability Index (HAQ-DI). Results: Amongst the 122 randomized patients, 99 (81.1%) patients completed the study. Adverse events (AEs) were reported in 114/122 (93.4%) patients and serious AEs were reported in 9/122 (7.4%) patients. No deaths, major cardiovascular AEs, serious gastrointestinal perforations or tuberculosis cases were reported during this study period. Grade 3 hematologic abnormalities (neutropenia and leukopenia) were reported in seven patients and no grade 4 abnormalities were observed. ACR20 responses were observed within 2 weeks, achieved in 47/61 (77.0%, 50 mg q4w) patients and 44/61 (72.1%, 100 mg q2w) patients at week 16 and maintained through week 52. ACR50/70, DAS28-CRP and HAQ-DI responses were also maintained through week 52 in both groups. Conclusions: Safety findings were comparable between the two treatment groups. The 52-week administration of sirukumab at 50 mg q4w and 100 mg q2w was generally tolerable and with measurable efficacy in Japanese patients with RA refractory to methotrexate and sulfasalazine.

Objective: To assess the efficacy and safety of secukinumab in patients with rheumatoid arthritis (RA) who failed to respond to tumour necrosis factor- α (TNF-α) inhibitors. Method: This phase III double-blind, double-dummy, placebo-controlled study (NCT01770379) randomized (1:1:1) patients to subcutaneous secukinumab 150 mg, secukinumab 75 mg, or placebo at baseline, weeks 1, 2, 3, and 4, and then every 4 weeks. American College of Rheumatology (ACR) 20 response at week 24 was the primary endpoint. Secondary outcomes included the 28-joint Disease Activity Score using C-reactive protein (DAS28-CRP), Health Assessment Questionnaire Disability Index (HAQ-DI), and ACR50 at week 24. Long-term treatment was planned for 5 years. Results: ACR20 response rates at week 24 for the secukinumab 150 mg and 75 mg groups were not statistically superior to placebo. None of the secondary endpoints was met for either secukinumab dose. Although not statistically significant, compared with placebo, numerically greater differences in least squares mean changes from baseline in HAQ-DI score and numerically higher ACR50 response rates were observed at week 24 in both secukinumab treatment groups. No new or unexpected adverse events were observed in this study compared with the large secukinumab safety database across psoriasis, psoriatic arthritis, ankylosing spondylitis, and other RA studies. Conclusions: Given that other second-line therapies have demonstrated efficacy in RA patients who failed to respond to TNF-α inhibitors, these findings may suggest that interleukin-17A inhibition with secukinumab does not provide additional benefit to these patients. This study further confirms the well-characterized safety profile of secukinumab.

IgG4-related disease (IgG4-RD) is a recently recognized disease entity characterized by high serum IgG4 concentrations and infiltration of IgG4+ plasma cells with hyperplastic ectopic germinal centres at affected sites. Although the underlying immune mechanism of this disease remains unclear, T cells are abundantly present at affected sites and key players in IgG4-RD pathogenesis. The role of T cell subsets has been investigated thoroughly in this disease. Recent advances in this field have clarified the importance of T follicular helper cells. In this review, we describe the role of T follicular helper cells in the disease process of IgG4-RD, in particular, for IgG4 class-switching, plasmablast and plasma cell differentiation, and germinal centre formation.

Objectives: To assess the determinants of Patient’s Global Assessment of Disease Activity (PtGA) and Physician’s Global Assessment of Disease Activity (PhGA) in overall and Japanese patients with rheumatoid arthritis (RA) from two large randomized controlled trials. Methods: Post hoc analysis of overall and Japanese RA patients who had previous inadequate responses to methotrexate or who had no/minimal previous disease-modifying antirheumatic drug treatment. We examined correlations between PtGA/PhGA and tender joint count in 28 joints (TJC28), swollen joint count in 28 joints (SJC28), inflammatory markers, pain visual analog scale (VAS), and other patient-reported outcomes at baseline, Week 12, and Week 24. Determinants of PtGA/PhGA were identified. Results: In overall populations, pain VAS was the main determinant of PtGA, whereas TJC28 was the main determinant of PhGA in both studies. In Japanese populations, consistent with overall populations, pain VAS was the main determinant of PtGA in both studies; in contrast to overall populations, pain VAS and SJC28/TJC28 played an important role in PhGA. Conclusion: Pain was the most important determinant of PtGA, whereas determinants of PhGA varied between populations/studies and were mostly explained by pain/joint counts. Physicians should be aware of patients’ perceptions of disease activity when performing assessments/prescribing treatments.

The aim of this study was to prospectively evaluate the efficacy and safety of tacrolimus for treating rheumatoid arthritis (RA) patients in clinical practice. Fifty-five active RA patients who had been resistant or intolerant to other disease-modifying antirheumatic drugs were enrolled in this open-label trial. Patients were administered tacrolimus at a dosage of 1, 2 or 3 mg once daily, and followed up for 24 weeks. They were divided into three groups according to their dosage. Efficacy and safety were evaluated utilizing clinical and laboratory findings. Eighty percent of the patients had moderate or high disease activity; 55% were elderly and 53% had complications; 65% of the patients were started on tacrolimus as a monotherapy. Moderate or good response rates were achieved as follows: 38.2% (4 weeks); 41.8% (12 weeks); and 45.6% (24 weeks). Adverse events were observed in seven cases (12.7%). Only one case required hospitalization due to severe hyperglycemia caused by a high tacrolimus concentration (24.2 ng/ml); we suspected a drug interaction in this subject. Mean concentrations were dose-dependent in the 1, 2, and 3 mg/day groups (2.96, 4.29, and 8.32 ng/ml, respectively). Four cases of high concentration (over 10 ng/ml), without any signs or symptoms, were observed in the 3 mg/day group; in these cases, doses were decreased and no severe adverse events occurred. Tacrolimus was found to be both effective and safe in treating active RA patients with complicated backgrounds in clinical practice. Blood concentration measurements and dose adjustments should be performed to prevent severe adverse events in a 3 mg/day group. © 2009 Springer-Verlag.

The killer cell lectin-like receptor G1 (KLRG1) is an inhibitory receptor expressed by memory T cells and NK cells in man and mice. It is frequently used as a cell differentiation marker and members of the cadherin family are ligands for KLRG1. The present study provides new insights into the interaction of mouse KLRG1 with E-cadherin. Firstly, we demonstrate that co-engagement of KLRG1 and CD3/TCR in a spatially linked manner was required for inhibition arguing against the notion that KLRG1-ligation per se transmits inhibitory signals. Secondly, experiments with T cells carrying Y7F-mutant KLRG1 molecules with a replacement of the tyrosine residue to phenylalanine in the single ITIM indicated that the inhibitory activity of KLRG1 is counteracted to some degree by increased interaction of KLRG1+ T cells with E-cadherin expressing target cells. Thirdly, we demonstrate that deletion of the first or the second external domain of E-cadherin abolished reactivity in KLRG1-reporter cell assays. Finally, we made the intriguing observation that KLRG1 formed multimeric protein complexes in T cells in addition to the previously described mono- and dimeric molecules. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.

The anti-TNF-α chimeric monoclonal antibody infliximab is the first biologic to be approved for rheumatoid arthritis (RA) in Japan, and post-marketing surveillance of all of the Japanese cases treated with infliximab has been conducted to explore the safety of infliximab therapy. In addition, a retrospective clinical study on the notable efficacy and related factors of infliximab therapy in an RA management group in Japan (RECONFIRM and RECONFIRM-2) has demonstrated clinical responses. However, information on the effect of infliximab on joint destruction in Japanese RA patients remains insufficient. In this study, we retrospectively analyzed X-ray data from 67 patients in whom both hand and foot X-rays at baseline and at 54 weeks had been available among the 410 cases in the RECONFIRM-2 study. By scoring the X-rays according to the modified van der Heijde (vdH)-Sharp method, we found that the total vdH-Sharp score in the RA patients before infliximab therapy was 104.40 ± 87.34 and the yearly progression was 21.33, indicating relatively rapid progression. After infliximab therapy for 54 weeks, the total vdH-Sharp score at 54 weeks was 104.37 ± 86.87 and the estimated yearly progression was -0.03, indicating the almost complete inhibition of progression. The RECONFIRM-2J study confirmed the significant ability of infliximab to halt joint destruction in Japanese RA patients, and showed that joint destruction was significantly associated with disease activity and the dose of MTX in the patients with moderate and advanced disease durations, respectively, before infliximab therapy. © Japan College of Rheumatology 2008.

Among the 5,043 consecutive patients registered in the postmarketing surveillance for leflunomide, 61 were reported to have lung injury and 24 died from it. The adjusted multivariate logistic regression analysis of the risk factors showed that preexisting interstitial lung disease posed the greatest risk, as well as loading dose, smoking history, and low body weight of 40 kg or less with odds ratios of 8.17, 3.97, 3.12, and 2.91, respectively. In 12 patients, lung injury developed even 2 months after leflunomide withdrawal. When patients with (n = 9) and without (n = 13) fatal outcome were compared, eight out of the former, and six out of the latter had preexisting interstitial lung disease; the former showed severe hypoxemia, high serum C-reactive protein level, hypoalbuminemia, and continuous lymphocytopenia, and required mechanical ventilation. On the basis of these results and literature review, the committee proposes that leflunomide should only be recommended as a second-line drug, should not be administered to patients with preexisting interstitial lung disease, should also not be administered to patients with smoking history or those with low body weight, and should be administered without loading dose. Careful monitoring is necessary, and when lung injury develops, leflunomide elimination using colestyramine is mandatory. © Japan College of Rheumatology 2008.